diff --git a/benchmark/_cli.js b/benchmark/_cli.js
index fa2bfb83955e73..8b9f22d0fb4b57 100644
--- a/benchmark/_cli.js
+++ b/benchmark/_cli.js
@@ -16,7 +16,7 @@ function CLI(usage, settings) {
   if (!(this instanceof CLI)) return new CLI(usage, settings);
 
   if (process.argv.length < 3) {
-    this.abort(usage); // abort will exit the process
+    this.abort(usage); // Abort will exit the process
   }
 
   this.usage = usage;
diff --git a/benchmark/common.js b/benchmark/common.js
index cad0550986bd18..b4778d71935e25 100644
--- a/benchmark/common.js
+++ b/benchmark/common.js
@@ -202,7 +202,7 @@ Benchmark.prototype.end = function(operations) {
   if (elapsed[0] === 0 && elapsed[1] === 0) {
     if (!process.env.NODEJS_BENCHMARK_ZERO_ALLOWED)
       throw new Error('insufficient clock precision for short benchmark');
-    // avoid dividing by zero
+    // Avoid dividing by zero
     elapsed[1] = 1;
   }
 
diff --git a/benchmark/crypto/hash-stream-creation.js b/benchmark/crypto/hash-stream-creation.js
index 8ffbe148bb71a5..0a98eb1471c9d4 100644
--- a/benchmark/crypto/hash-stream-creation.js
+++ b/benchmark/crypto/hash-stream-creation.js
@@ -1,4 +1,4 @@
-// throughput benchmark
+// Throughput benchmark
 // creates a single hasher, then pushes a bunch of data through it
 'use strict';
 const common = require('../common.js');
diff --git a/benchmark/crypto/hash-stream-throughput.js b/benchmark/crypto/hash-stream-throughput.js
index 6ce7a6767e4880..52be3d4caf8501 100644
--- a/benchmark/crypto/hash-stream-throughput.js
+++ b/benchmark/crypto/hash-stream-throughput.js
@@ -1,4 +1,4 @@
-// throughput benchmark
+// Throughput benchmark
 // creates a single hasher, then pushes a bunch of data through it
 'use strict';
 const common = require('../common.js');
diff --git a/benchmark/fixtures/simple-http-server.js b/benchmark/fixtures/simple-http-server.js
index 0eb7d9ee374615..013ac468f551ff 100644
--- a/benchmark/fixtures/simple-http-server.js
+++ b/benchmark/fixtures/simple-http-server.js
@@ -9,7 +9,7 @@ const storedUnicode = Object.create(null);
 
 const useDomains = process.env.NODE_USE_DOMAINS;
 
-// set up one global domain.
+// Set up one global domain.
 if (useDomains) {
   var domain = require('domain');
   const gdom = domain.create();
diff --git a/benchmark/http/cluster.js b/benchmark/http/cluster.js
index 35d0ba98d00b43..7f72db533ed142 100644
--- a/benchmark/http/cluster.js
+++ b/benchmark/http/cluster.js
@@ -5,7 +5,7 @@ const PORT = common.PORT;
 const cluster = require('cluster');
 if (cluster.isMaster) {
   var bench = common.createBenchmark(main, {
-    // unicode confuses ab on os x.
+    // Unicode confuses ab on os x.
     type: ['bytes', 'buffer'],
     len: [4, 1024, 102400],
     c: [50, 500]
diff --git a/benchmark/http/incoming_headers.js b/benchmark/http/incoming_headers.js
index 7d9955766c7882..f10178c1891805 100644
--- a/benchmark/http/incoming_headers.js
+++ b/benchmark/http/incoming_headers.js
@@ -3,7 +3,7 @@ const common = require('../common.js');
 const http = require('http');
 
 const bench = common.createBenchmark(main, {
-  // unicode confuses ab on os x.
+  // Unicode confuses ab on os x.
   c: [50, 500],
   n: [0, 5, 20]
 });
diff --git a/benchmark/http/simple.js b/benchmark/http/simple.js
index c6faaaa9efdfd2..2d89dce9be9b98 100644
--- a/benchmark/http/simple.js
+++ b/benchmark/http/simple.js
@@ -2,7 +2,7 @@
 const common = require('../common.js');
 
 const bench = common.createBenchmark(main, {
-  // unicode confuses ab on os x.
+  // Unicode confuses ab on os x.
   type: ['bytes', 'buffer'],
   len: [4, 1024, 102400],
   chunks: [1, 4],
diff --git a/benchmark/net/net-c2s-cork.js b/benchmark/net/net-c2s-cork.js
index 34c4b50296ec75..12d15fe0795e57 100644
--- a/benchmark/net/net-c2s-cork.js
+++ b/benchmark/net/net-c2s-cork.js
@@ -33,7 +33,7 @@ function main({ dur, len, type }) {
 
   const writer = new Writer();
 
-  // the actual benchmark.
+  // The actual benchmark.
   const server = net.createServer((socket) => {
     socket.pipe(writer);
   });
diff --git a/benchmark/net/net-c2s.js b/benchmark/net/net-c2s.js
index 732bda131d6b5a..4b64cbeca18124 100644
--- a/benchmark/net/net-c2s.js
+++ b/benchmark/net/net-c2s.js
@@ -34,7 +34,7 @@ function main({ dur, len, type }) {
   const reader = new Reader();
   const writer = new Writer();
 
-  // the actual benchmark.
+  // The actual benchmark.
   const server = net.createServer((socket) => {
     socket.pipe(writer);
   });
diff --git a/benchmark/net/net-pipe.js b/benchmark/net/net-pipe.js
index 12db1e13b836d2..c4e1da3f6f0c8b 100644
--- a/benchmark/net/net-pipe.js
+++ b/benchmark/net/net-pipe.js
@@ -34,7 +34,7 @@ function main({ dur, len, type }) {
   const reader = new Reader();
   const writer = new Writer();
 
-  // the actual benchmark.
+  // The actual benchmark.
   const server = net.createServer((socket) => {
     socket.pipe(socket);
   });
diff --git a/benchmark/net/net-s2c.js b/benchmark/net/net-s2c.js
index 848168cda45d83..e3c5c7e5eb41c6 100644
--- a/benchmark/net/net-s2c.js
+++ b/benchmark/net/net-s2c.js
@@ -33,7 +33,7 @@ function main({ dur, len, type }) {
   const reader = new Reader();
   const writer = new Writer();
 
-  // the actual benchmark.
+  // The actual benchmark.
   const server = net.createServer((socket) => {
     reader.pipe(socket);
   });
diff --git a/benchmark/net/net-wrap-js-stream-passthrough.js b/benchmark/net/net-wrap-js-stream-passthrough.js
index 1c597b6ed0a199..1e8a1ee1c5a092 100644
--- a/benchmark/net/net-wrap-js-stream-passthrough.js
+++ b/benchmark/net/net-wrap-js-stream-passthrough.js
@@ -38,7 +38,7 @@ function main({ dur, len, type }) {
   const reader = new Reader();
   const writer = new Writer();
 
-  // the actual benchmark.
+  // The actual benchmark.
   const fakeSocket = new JSStreamWrap(new PassThrough());
   bench.start();
   reader.pipe(fakeSocket);
diff --git a/benchmark/url/legacy-vs-whatwg-url-parse.js b/benchmark/url/legacy-vs-whatwg-url-parse.js
index e4af2e0b7c2db5..e3f50a76a45c77 100644
--- a/benchmark/url/legacy-vs-whatwg-url-parse.js
+++ b/benchmark/url/legacy-vs-whatwg-url-parse.js
@@ -13,7 +13,7 @@ const bench = common.createBenchmark(main, {
 
 function useLegacy(data) {
   const len = data.length;
-  var result = url.parse(data[0]);  // avoid dead code elimination
+  var result = url.parse(data[0]);  // Avoid dead code elimination
   bench.start();
   for (var i = 0; i < len; ++i) {
     result = url.parse(data[i]);
@@ -24,7 +24,7 @@ function useLegacy(data) {
 
 function useWHATWGWithBase(data) {
   const len = data.length;
-  var result = new URL(data[0][0], data[0][1]);  // avoid dead code elimination
+  var result = new URL(data[0][0], data[0][1]);  // Avoid dead code elimination
   bench.start();
   for (var i = 0; i < len; ++i) {
     const item = data[i];
@@ -36,7 +36,7 @@ function useWHATWGWithBase(data) {
 
 function useWHATWGWithoutBase(data) {
   const len = data.length;
-  var result = new URL(data[0]);  // avoid dead code elimination
+  var result = new URL(data[0]);  // Avoid dead code elimination
   bench.start();
   for (var i = 0; i < len; ++i) {
     result = new URL(data[i]);
diff --git a/benchmark/url/url-searchparams-sort.js b/benchmark/url/url-searchparams-sort.js
index 6720b66dca366f..0d4f605fa8edd6 100644
--- a/benchmark/url/url-searchparams-sort.js
+++ b/benchmark/url/url-searchparams-sort.js
@@ -3,7 +3,7 @@ const common = require('../common.js');
 const URLSearchParams = require('url').URLSearchParams;
 
 const inputs = {
-  wpt: 'wpt',  // to work around tests
+  wpt: 'wpt',  // To work around tests
   empty: '',
   sorted: 'a&b&c&d&e&f&g&h&i&j&k&l&m&n&o&p&q&r&s&t&u&v&w&x&y&z',
   almostsorted: 'a&b&c&d&e&f&g&i&h&j&k&l&m&n&o&p&q&r&s&t&u&w&v&x&y&z',
diff --git a/doc/api/cluster.md b/doc/api/cluster.md
index 90e64239b3b198..340c2968cb6fb0 100644
--- a/doc/api/cluster.md
+++ b/doc/api/cluster.md
@@ -315,7 +315,7 @@ if (cluster.isMaster) {
 } else if (cluster.isWorker) {
   const net = require('net');
   const server = net.createServer((socket) => {
-    // connections never end
+    // Connections never end
   });
 
   server.listen(8000);
diff --git a/doc/api/console.md b/doc/api/console.md
index 1fe1949664920f..a8369290dfbf0f 100644
--- a/doc/api/console.md
+++ b/doc/api/console.md
@@ -114,12 +114,12 @@ error output. If `stderr` is not provided, `stdout` is used for `stderr`.
 ```js
 const output = fs.createWriteStream('./stdout.log');
 const errorOutput = fs.createWriteStream('./stderr.log');
-// custom simple logger
+// Custom simple logger
 const logger = new Console({ stdout: output, stderr: errorOutput });
 // use it like console
 const count = 5;
 logger.log('count: %d', count);
-// in stdout.log: count 5
+// In stdout.log: count 5
 ```
 
 The global `console` is a special `Console` whose output is sent to
diff --git a/doc/api/domain.md b/doc/api/domain.md
index 226eb660f4b0bf..63dbcabbbc205d 100644
--- a/doc/api/domain.md
+++ b/doc/api/domain.md
@@ -135,7 +135,7 @@ if (cluster.isMaster) {
         // But don't keep the process open just for that!
         killtimer.unref();
 
-        // stop taking new requests.
+        // Stop taking new requests.
         server.close();
 
         // Let the master know we're dead. This will trigger a
@@ -316,14 +316,13 @@ const d = domain.create();
 
 function readSomeFile(filename, cb) {
   fs.readFile(filename, 'utf8', d.bind((er, data) => {
-    // If this throws, it will also be passed to the domain
+    // If this throws, it will also be passed to the domain.
     return cb(er, data ? JSON.parse(data) : null);
   }));
 }
 
 d.on('error', (er) => {
-  // an error occurred somewhere.
-  // if we throw it now, it will crash the program
+  // An error occurred somewhere. If we throw it now, it will crash the program
   // with the normal line number and stack message.
 });
 ```
@@ -377,7 +376,7 @@ function readSomeFile(filename, cb) {
     // callback since it is assumed to be the 'Error' argument
     // and thus intercepted by the domain.
 
-    // if this throws, it will also be passed to the domain
+    // If this throws, it will also be passed to the domain
     // so the error-handling logic can be moved to the 'error'
     // event on the domain instead of being repeated throughout
     // the program.
@@ -386,8 +385,7 @@ function readSomeFile(filename, cb) {
 }
 
 d.on('error', (er) => {
-  // an error occurred somewhere.
-  // if we throw it now, it will crash the program
+  // An error occurred somewhere. If we throw it now, it will crash the program
   // with the normal line number and stack message.
 });
 ```
diff --git a/doc/api/errors.md b/doc/api/errors.md
index 18774a9b951884..7e32ba1cfc94be 100644
--- a/doc/api/errors.md
+++ b/doc/api/errors.md
@@ -407,7 +407,7 @@ program.
 try {
   require('vm').runInThisContext('binary ! isNotOk');
 } catch (err) {
-  // err will be a SyntaxError
+  // 'err' will be a SyntaxError.
 }
 ```
 
@@ -422,7 +422,7 @@ string would be considered a `TypeError`.
 
 ```js
 require('url').parse(() => { });
-// throws TypeError, since it expected a string
+// Throws TypeError, since it expected a string.
 ```
 
 Node.js will generate and throw `TypeError` instances *immediately* as a form
diff --git a/doc/api/events.md b/doc/api/events.md
index 8525bf5f2483f2..74846995c2e9aa 100644
--- a/doc/api/events.md
+++ b/doc/api/events.md
@@ -648,7 +648,7 @@ emitter.on('log', () => console.log('log persistently'));
 // Will return a new Array with a single function bound by `.on()` above
 const newListeners = emitter.rawListeners('log');
 
-// logs "log persistently" twice
+// Logs "log persistently" twice
 newListeners[0]();
 emitter.emit('log');
 ```
diff --git a/doc/api/http.md b/doc/api/http.md
index d27fa462a85346..455195d79f0c93 100644
--- a/doc/api/http.md
+++ b/doc/api/http.md
@@ -358,7 +358,7 @@ const proxy = http.createServer((req, res) => {
   res.end('okay');
 });
 proxy.on('connect', (req, cltSocket, head) => {
-  // connect to an origin server
+  // Connect to an origin server
   const srvUrl = url.parse(`http://${req.url}`);
   const srvSocket = net.connect(srvUrl.port, srvUrl.hostname, () => {
     cltSocket.write('HTTP/1.1 200 Connection Established\r\n' +
@@ -370,7 +370,7 @@ proxy.on('connect', (req, cltSocket, head) => {
   });
 });
 
-// now that proxy is running
+// Now that proxy is running
 proxy.listen(1337, '127.0.0.1', () => {
 
   // Make a request to a tunneling proxy
@@ -504,7 +504,7 @@ srv.on('upgrade', (req, socket, head) => {
   socket.pipe(socket); // echo back
 });
 
-// now that server is running
+// Now that server is running
 srv.listen(1337, '127.0.0.1', () => {
 
   // make a request
@@ -626,11 +626,11 @@ request.setHeader('content-type', 'text/html');
 request.setHeader('Content-Length', Buffer.byteLength(body));
 request.setHeader('Cookie', ['type=ninja', 'language=javascript']);
 const contentType = request.getHeader('Content-Type');
-// contentType is 'text/html'
+// 'contentType' is 'text/html'
 const contentLength = request.getHeader('Content-Length');
-// contentLength is of type number
+// 'contentLength' is of type number
 const cookie = request.getHeader('Cookie');
-// cookie is of type string[]
+// 'cookie' is of type string[]
 ```
 
 ### request.maxHeadersCount
@@ -745,7 +745,7 @@ req.once('response', (res) => {
   const ip = req.socket.localAddress;
   const port = req.socket.localPort;
   console.log(`Your IP address is ${ip} and your source port is ${port}.`);
-  // consume response object
+  // Consume response object
 });
 ```
 
@@ -2065,7 +2065,7 @@ req.on('error', (e) => {
   console.error(`problem with request: ${e.message}`);
 });
 
-// write data to request body
+// Write data to request body
 req.write(postData);
 req.end();
 ```
diff --git a/doc/api/http2.md b/doc/api/http2.md
index 04a4972de785d2..1416c976362afe 100644
--- a/doc/api/http2.md
+++ b/doc/api/http2.md
@@ -2437,7 +2437,7 @@ const client = http2.connect('http://localhost');
 
 client.on('stream', (pushedStream, requestHeaders) => {
   pushedStream.on('push', (responseHeaders) => {
-    // process response headers
+    // Process response headers
   });
   pushedStream.on('data', (chunk) => { /* handle pushed data */ });
 });
diff --git a/doc/api/process.md b/doc/api/process.md
index 27ba6db319ac8e..ed5e38dd4c817a 100644
--- a/doc/api/process.md
+++ b/doc/api/process.md
@@ -295,8 +295,8 @@ process.on('unhandledRejection', (reason, p) => {
 });
 
 somePromise.then((res) => {
-  return reportToUser(JSON.pasre(res)); // note the typo (`pasre`)
-}); // no `.catch()` or `.then()`
+  return reportToUser(JSON.pasre(res)); // Note the typo (`pasre`)
+}); // No `.catch()` or `.then()`
 ```
 
 The following will also trigger the `'unhandledRejection'` event to be
diff --git a/doc/api/querystring.md b/doc/api/querystring.md
index 1a1d0adb25f0d5..15fb35d22f627f 100644
--- a/doc/api/querystring.md
+++ b/doc/api/querystring.md
@@ -126,7 +126,7 @@ querystring.stringify({ foo: 'bar', baz: ['qux', 'quux'], corge: '' });
 // Returns 'foo=bar&baz=qux&baz=quux&corge='
 
 querystring.stringify({ foo: 'bar', baz: 'qux' }, ';', ':');
-// returns 'foo:bar;baz:qux'
+// Returns 'foo:bar;baz:qux'
 ```
 
 By default, characters requiring percent-encoding within the query string will
diff --git a/doc/api/stream.md b/doc/api/stream.md
index 156f09f374c5bf..df171b95369741 100644
--- a/doc/api/stream.md
+++ b/doc/api/stream.md
@@ -683,7 +683,7 @@ pass.unpipe(writable);
 // readableFlowing is now false
 
 pass.on('data', (chunk) => { console.log(chunk.toString()); });
-pass.write('ok');  // will not emit 'data'
+pass.write('ok');  // Will not emit 'data'
 pass.resume();     // Must be called to make stream emit 'data'
 ```
 
@@ -1206,7 +1206,7 @@ function parseHeader(stream, callback) {
     while (null !== (chunk = stream.read())) {
       const str = decoder.write(chunk);
       if (str.match(/\n\n/)) {
-        // found the header boundary
+        // Found the header boundary
         const split = str.split(/\n\n/);
         header += split.shift();
         const remaining = split.join('\n\n');
@@ -1219,7 +1219,7 @@ function parseHeader(stream, callback) {
         // Now the body of the message can be read from the stream.
         callback(null, header, stream);
       } else {
-        // still reading the header.
+        // Still reading the header.
         header += str;
       }
     }
diff --git a/doc/api/timers.md b/doc/api/timers.md
index 9460028928bba1..66ee2ca97e8455 100644
--- a/doc/api/timers.md
+++ b/doc/api/timers.md
@@ -163,7 +163,7 @@ setImmediatePromise('foobar').then((value) => {
   // This is executed after all I/O callbacks.
 });
 
-// or with async function
+// Or with async function
 async function timerExample() {
   console.log('Before I/O callbacks');
   await setImmediatePromise();
diff --git a/doc/api/util.md b/doc/api/util.md
index 2ef115bc7d4dec..beb79ae0f85616 100644
--- a/doc/api/util.md
+++ b/doc/api/util.md
@@ -758,7 +758,7 @@ option properties directly is also supported.
 const util = require('util');
 const arr = Array(101).fill(0);
 
-console.log(arr); // logs the truncated array
+console.log(arr); // Logs the truncated array
 util.inspect.defaultOptions.maxArrayLength = null;
 console.log(arr); // logs the full array
 ```
diff --git a/doc/api/zlib.md b/doc/api/zlib.md
index 6efc2a709c339d..6d0371a8d9a083 100644
--- a/doc/api/zlib.md
+++ b/doc/api/zlib.md
@@ -69,7 +69,7 @@ See [Memory Usage Tuning][] for more information on the speed/memory/compression
 tradeoffs involved in `zlib` usage.
 
 ```js
-// client request example
+// Client request example
 const zlib = require('zlib');
 const http = require('http');
 const fs = require('fs');
diff --git a/lib/_http_server.js b/lib/_http_server.js
index 5941e5740fcf91..fc02a66e2eecc7 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -239,10 +239,10 @@ function writeHead(statusCode, reason, obj) {
     if (k === undefined && this._header) {
       throw new ERR_HTTP_HEADERS_SENT('render');
     }
-    // only progressive api is used
+    // Only progressive api is used
     headers = this[outHeadersKey];
   } else {
-    // only writeHead() called
+    // Only writeHead() called
     headers = obj;
   }
 
@@ -440,7 +440,7 @@ function socketOnTimeout() {
 
 function socketOnClose(socket, state) {
   debug('server socket close');
-  // mark this parser as reusable
+  // Mark this parser as reusable
   if (socket.parser) {
     freeParser(socket.parser, null, socket);
   }
@@ -455,7 +455,7 @@ function abortIncoming(incoming) {
     req.emit('aborted');
     req.emit('close');
   }
-  // abort socket._httpMessage ?
+  // Abort socket._httpMessage ?
 }
 
 function socketOnEnd(server, socket, parser, state) {
diff --git a/lib/_stream_duplex.js b/lib/_stream_duplex.js
index 05140acac30fc9..11651e2ace65a5 100644
--- a/lib/_stream_duplex.js
+++ b/lib/_stream_duplex.js
@@ -96,13 +96,13 @@ Object.defineProperty(Duplex.prototype, 'writableLength', {
   }
 });
 
-// the no-half-open enforcer
+// The no-half-open enforcer
 function onend() {
   // If the writable side ended, then we're ok.
   if (this._writableState.ended)
     return;
 
-  // no more data can be written.
+  // No more data can be written.
   // But allow more writes to happen in this tick.
   process.nextTick(onEndNT, this);
 }
diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index 79a12dd4350d31..81e8de310c240f 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -130,7 +130,7 @@ function ReadableState(options, stream, isDuplex) {
   // Should .destroy() be called after 'end' (and potentially 'finish')
   this.autoDestroy = !!options.autoDestroy;
 
-  // has it been destroyed
+  // Has it been destroyed
   this.destroyed = false;
 
   // Crypto is kind of old and crusty.  Historically, its default string
@@ -295,7 +295,7 @@ function addChunk(stream, state, chunk, addToFront) {
     state.awaitDrain = 0;
     stream.emit('data', chunk);
   } else {
-    // update the buffer info.
+    // Update the buffer info.
     state.length += state.objectMode ? 1 : chunk.length;
     if (addToFront)
       state.buffer.unshift(chunk);
@@ -323,7 +323,7 @@ Readable.prototype.isPaused = function() {
   return this._readableState.flowing === false;
 };
 
-// backwards compatibility.
+// Backwards compatibility.
 Readable.prototype.setEncoding = function(enc) {
   if (!StringDecoder)
     StringDecoder = require('string_decoder').StringDecoder;
@@ -459,7 +459,7 @@ Readable.prototype.read = function(n) {
     // If the length is currently zero, then we *need* a readable event.
     if (state.length === 0)
       state.needReadable = true;
-    // call internal read method
+    // Call internal read method
     this._read(state.highWaterMark);
     state.sync = false;
     // If _read pushed data synchronously, then `reading` will be false,
@@ -818,7 +818,7 @@ Readable.prototype.unpipe = function(dest) {
     return this;
   }
 
-  // try to find the right one.
+  // Try to find the right one.
   var index = state.pipes.indexOf(dest);
   if (index === -1)
     return this;
@@ -1006,8 +1006,7 @@ Readable.prototype.wrap = function(stream) {
     }
   });
 
-  // proxy all the other methods.
-  // important when wrapping filters and duplexes.
+  // Proxy all the other methods. Important when wrapping filters and duplexes.
   for (var i in stream) {
     if (this[i] === undefined && typeof stream[i] === 'function') {
       this[i] = function methodWrap(method) {
diff --git a/lib/_stream_writable.js b/lib/_stream_writable.js
index fa7b851249e284..486d044cb0091d 100644
--- a/lib/_stream_writable.js
+++ b/lib/_stream_writable.js
@@ -80,14 +80,14 @@ function WritableState(options, stream, isDuplex) {
 
   // drain event flag.
   this.needDrain = false;
-  // at the start of calling end()
+  // At the start of calling end()
   this.ending = false;
   // When end() has been called, and returned
   this.ended = false;
-  // when 'finish' is emitted
+  // When 'finish' is emitted
   this.finished = false;
 
-  // has it been destroyed
+  // Has it been destroyed
   this.destroyed = false;
 
   // Should we decode strings into buffers before passing to _write?
@@ -152,7 +152,7 @@ function WritableState(options, stream, isDuplex) {
   // Should .destroy() be called after 'finish' (and potentially 'end')
   this.autoDestroy = !!options.autoDestroy;
 
-  // count buffered requests
+  // Count buffered requests
   this.bufferedRequestCount = 0;
 
   // Allocate the first CorkedRequest, there is always
@@ -681,7 +681,7 @@ function onCorkedFinish(corkReq, state, err) {
     entry = entry.next;
   }
 
-  // reuse the free corkReq.
+  // Reuse the free corkReq.
   state.corkedRequestsFree.next = corkReq;
 }
 
diff --git a/lib/buffer.js b/lib/buffer.js
index b072ac407d6ffc..66c345885a7d59 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -356,7 +356,7 @@ function fromArrayLike(obj) {
 }
 
 function fromArrayBuffer(obj, byteOffset, length) {
-  // convert byteOffset to integer
+  // Convert byteOffset to integer
   if (byteOffset === undefined) {
     byteOffset = 0;
   } else {
diff --git a/lib/dgram.js b/lib/dgram.js
index 97709b1d948ded..a81c08f7285eab 100644
--- a/lib/dgram.js
+++ b/lib/dgram.js
@@ -262,7 +262,7 @@ Socket.prototype.bind = function(port_, address_ /* , callback */) {
       address = '::';
   }
 
-  // resolve address first
+  // Resolve address first
   state.handle.lookup(address, (err, ip) => {
     if (err) {
       state.bindState = BIND_STATE_UNBOUND;
diff --git a/lib/domain.js b/lib/domain.js
index 46b810857482f6..144d66862449c1 100644
--- a/lib/domain.js
+++ b/lib/domain.js
@@ -68,7 +68,7 @@ const asyncHook = createHook({
   },
   before(asyncId) {
     const current = pairing.get(asyncId);
-    if (current !== undefined) { // enter domain for this cb
+    if (current !== undefined) { // Enter domain for this cb
       // We will get the domain through current.get(), because the resource
       // object's .domain property makes sure it is not garbage collected.
       current.get().enter();
@@ -76,7 +76,7 @@ const asyncHook = createHook({
   },
   after(asyncId) {
     const current = pairing.get(asyncId);
-    if (current !== undefined) { // exit domain for this cb
+    if (current !== undefined) { // Exit domain for this cb
       current.get().exit();
     }
   },
diff --git a/lib/fs.js b/lib/fs.js
index 8aeaffb8ec17c3..206ab1fcfe669f 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -121,7 +121,7 @@ function handleErrorFromBinding(ctx) {
     Error.captureStackTrace(err, handleErrorFromBinding);
     throw err;
   }
-  if (ctx.error !== undefined) {  // errors created in C++ land.
+  if (ctx.error !== undefined) {  // Errors created in C++ land.
     // TODO(joyeecheung): currently, ctx.error are encoding errors
     // usually caused by memory problems. We need to figure out proper error
     // code(s) for this.
@@ -289,7 +289,7 @@ function readFile(path, options, callback) {
   if (!ReadFileContext)
     ReadFileContext = require('internal/fs/read_file_context');
   const context = new ReadFileContext(callback, options.encoding);
-  context.isUserFd = isFd(path); // file descriptor ownership
+  context.isUserFd = isFd(path); // File descriptor ownership
 
   const req = new FSReqCallback();
   req.context = context;
@@ -349,14 +349,14 @@ function tryReadSync(fd, isUserFd, buffer, pos, len) {
 
 function readFileSync(path, options) {
   options = getOptions(options, { flag: 'r' });
-  const isUserFd = isFd(path); // file descriptor ownership
+  const isUserFd = isFd(path); // File descriptor ownership
   const fd = isUserFd ? path : fs.openSync(path, options.flag, 0o666);
 
   const stats = tryStatSync(fd, isUserFd);
   const size = isFileType(stats, S_IFREG) ? stats[8] : 0;
   let pos = 0;
-  let buffer; // single buffer with file data
-  let buffers; // list for when size is unknown
+  let buffer; // Single buffer with file data
+  let buffers; // List for when size is unknown
 
   if (size === 0) {
     buffers = [];
@@ -1242,7 +1242,7 @@ function writeFileSync(path, data, options) {
   options = getOptions(options, { encoding: 'utf8', mode: 0o666, flag: 'w' });
   const flag = options.flag || 'w';
 
-  const isUserFd = isFd(path); // file descriptor ownership
+  const isUserFd = isFd(path); // File descriptor ownership
   const fd = isUserFd ? path : fs.openSync(path, flag, options.mode);
 
   if (!isArrayBufferView(data)) {
diff --git a/lib/internal/child_process.js b/lib/internal/child_process.js
index dddfd7cbeceb73..390feef96abf30 100644
--- a/lib/internal/child_process.js
+++ b/lib/internal/child_process.js
@@ -565,7 +565,7 @@ function setupChannel(target, channel) {
   // Object where socket lists will live
   channel.sockets = { got: {}, send: {} };
 
-  // handlers will go through this
+  // Handlers will go through this
   target.on('internalMessage', function(message, handle) {
     // Once acknowledged - continue sending handles.
     if (message.cmd === 'NODE_HANDLE_ACK' ||
diff --git a/lib/internal/freeze_intrinsics.js b/lib/internal/freeze_intrinsics.js
index effac318539270..5d58121a25511c 100644
--- a/lib/internal/freeze_intrinsics.js
+++ b/lib/internal/freeze_intrinsics.js
@@ -14,7 +14,7 @@
 // limitations under the License.
 // SPDX-License-Identifier: MIT
 
-// based upon:
+// Based upon:
 // https://github.com/google/caja/blob/master/src/com/google/caja/ses/startSES.js
 // https://github.com/google/caja/blob/master/src/com/google/caja/ses/repairES5.js
 // https://github.com/tc39/proposal-frozen-realms/blob/91ac390e3451da92b5c27e354b39e52b7636a437/shim/src/deep-freeze.js
@@ -176,11 +176,11 @@ module.exports = function() {
           // NB: handle for any new cases in future
         }
         if (frozenSet.has(val) || freezingSet.has(val)) {
-          // todo use uncurried form
+          // TODO: Use uncurried form
           // Ignore if already frozen or freezing
           return;
         }
-        freezingSet.add(val); // todo use uncurried form
+        freezingSet.add(val); // TODO: Use uncurried form
       }
 
       function doFreeze(obj) {
@@ -201,8 +201,8 @@ module.exports = function() {
         const descs = getOwnPropertyDescriptors(obj);
         enqueue(proto);
         ownKeys(descs).forEach((name) => {
-          // todo uncurried form
-          // todo: getOwnPropertyDescriptors is guaranteed to return well-formed
+          // TODO: Uncurried form
+          // TODO: getOwnPropertyDescriptors is guaranteed to return well-formed
           // descriptors, but they still inherit from Object.prototype. If
           // someone has poisoned Object.prototype to add 'value' or 'get'
           // properties, then a simple 'if ("value" in desc)' or 'desc.value'
@@ -222,12 +222,12 @@ module.exports = function() {
 
       function dequeue() {
         // New values added before forEach() has finished will be visited.
-        freezingSet.forEach(doFreeze); // todo curried forEach
+        freezingSet.forEach(doFreeze); // TODO: Curried forEach
       }
 
       function commit() {
-        // todo curried forEach
-        // we capture the real WeakSet.prototype.add above, in case someone
+        // TODO: Curried forEach
+        // We capture the real WeakSet.prototype.add above, in case someone
         // changes it. The two-argument form of forEach passes the second
         // argument as the 'this' binding, so we add to the correct set.
         freezingSet.forEach(frozenSet.add, frozenSet);
diff --git a/lib/internal/fs/streams.js b/lib/internal/fs/streams.js
index b057ddb9bd2740..24c79dffb54ee5 100644
--- a/lib/internal/fs/streams.js
+++ b/lib/internal/fs/streams.js
@@ -121,7 +121,7 @@ ReadStream.prototype.open = function() {
     this.fd = fd;
     this.emit('open', fd);
     this.emit('ready');
-    // start the flow of data.
+    // Start the flow of data.
     this.read();
   });
 };
@@ -137,7 +137,7 @@ ReadStream.prototype._read = function(n) {
     return;
 
   if (!pool || pool.length - pool.used < kMinPoolSpace) {
-    // discard the old pool.
+    // Discard the old pool.
     allocNewPool(this.readableHighWaterMark);
   }
 
diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index f205b47a4a2798..b7486db6e47c05 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -711,7 +711,7 @@ Module.prototype.load = function(filename) {
     const module = ESMLoader.moduleMap.get(url);
     // Create module entry at load time to snapshot exports correctly
     const exports = this.exports;
-    if (module !== undefined) { // called from cjs translator
+    if (module !== undefined) { // Called from cjs translator
       module.reflect.onReady((reflect) => {
         reflect.exports.default.set(exports);
       });
@@ -885,7 +885,7 @@ if (experimentalModules) {
   };
 }
 
-// bootstrap main module.
+// Bootstrap main module.
 Module.runMain = function() {
   // Load the main module--the command line argument.
   if (experimentalModules) {
diff --git a/lib/internal/modules/esm/translators.js b/lib/internal/modules/esm/translators.js
index 97a7f4a2f354f2..de09910872e133 100644
--- a/lib/internal/modules/esm/translators.js
+++ b/lib/internal/modules/esm/translators.js
@@ -86,7 +86,7 @@ translators.set('cjs', async (url, isMain) => {
 // through normal resolution
 translators.set('builtin', async (url) => {
   debug(`Translating BuiltinModule ${url}`);
-  // slice 'node:' scheme
+  // Slice 'node:' scheme
   const id = url.slice(5);
   const module = NativeModule.map.get(id);
   if (!module) {
diff --git a/lib/internal/process/per_thread.js b/lib/internal/process/per_thread.js
index 5706d560baeb9c..7d2e83100c7939 100644
--- a/lib/internal/process/per_thread.js
+++ b/lib/internal/process/per_thread.js
@@ -167,7 +167,7 @@ function wrapProcessMethods(binding) {
       throw new ERR_INVALID_ARG_TYPE('pid', 'number', pid);
     }
 
-    // preserve null signal
+    // Preserve null signal
     if (sig === (sig | 0)) {
       // XXX(joyeecheung): we have to use process._kill here because
       // it's monkey-patched by tests.
@@ -268,12 +268,12 @@ function buildAllowedFlags() {
     }
 
     delete() {
-      // noop, `Set` API compatible
+      // No-op, `Set` API compatible
       return false;
     }
 
     clear() {
-      // noop
+      // No-op
     }
 
     has(key) {
diff --git a/lib/internal/readline.js b/lib/internal/readline.js
index b05c2d575a31dc..a5611942977df8 100644
--- a/lib/internal/readline.js
+++ b/lib/internal/readline.js
@@ -186,7 +186,7 @@ function* emitKeys(stream) {
     }
 
     if (escaped && (ch === 'O' || ch === '[')) {
-      // ansi escape sequence
+      // ANSI escape sequence
       let code = ch;
       let modifier = 0;
 
@@ -407,7 +407,7 @@ function* emitKeys(stream) {
       key.name = String.fromCharCode(ch.charCodeAt(0) + 'a'.charCodeAt(0) - 1);
       key.ctrl = true;
     } else if (/^[0-9A-Za-z]$/.test(ch)) {
-      // letter, number, shift+letter
+      // Letter, number, shift+letter
       key.name = ch.toLowerCase();
       key.shift = /^[A-Z]$/.test(ch);
       key.meta = escaped;
diff --git a/lib/internal/streams/async_iterator.js b/lib/internal/streams/async_iterator.js
index 0d22e4efeec99c..16d1316b168f01 100644
--- a/lib/internal/streams/async_iterator.js
+++ b/lib/internal/streams/async_iterator.js
@@ -18,9 +18,7 @@ function readAndResolve(iter) {
   const resolve = iter[kLastResolve];
   if (resolve !== null) {
     const data = iter[kStream].read();
-    // we defer if data is null
-    // we can be expecting either 'end' or
-    // 'error'
+    // We defer if data is null. We can be expecting either 'end' or 'error'.
     if (data !== null) {
       iter[kLastPromise] = null;
       iter[kLastResolve] = null;
@@ -32,7 +30,7 @@ function readAndResolve(iter) {
 
 function onReadable(iter) {
   // We wait for the next tick, because it might
-  // emit an error with process.nextTick
+  // emit an error with `process.nextTick()`.
   process.nextTick(readAndResolve, iter);
 }
 
@@ -59,7 +57,7 @@ const ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf({
 
   next() {
     // If we have detected an error in the meanwhile
-    // reject straight away
+    // reject straight away.
     const error = this[kError];
     if (error !== null) {
       return Promise.reject(error);
@@ -110,9 +108,9 @@ const ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf({
   },
 
   return() {
-    // destroy(err, cb) is a private API
-    // we can guarantee we have that here, because we control the
-    // Readable class this is attached to
+    // destroy(err, cb) is a private API.
+    // We can guarantee we have that here, because we control the
+    // Readable class this is attached to.
     return new Promise((resolve, reject) => {
       this[kStream].destroy(null, (err) => {
         if (err) {
@@ -135,9 +133,8 @@ const createReadableStreamAsyncIterator = (stream) => {
       value: stream._readableState.endEmitted,
       writable: true
     },
-    // The function passed to new Promise
-    // is cached so we avoid allocating a new
-    // closure at every run
+    // The function passed to new Promise is cached so we avoid allocating a new
+    // closure at every run.
     [kHandlePromise]: {
       value: (resolve, reject) => {
         const data = iterator[kStream].read();
@@ -159,8 +156,8 @@ const createReadableStreamAsyncIterator = (stream) => {
   finished(stream, (err) => {
     if (err && err.code !== 'ERR_STREAM_PREMATURE_CLOSE') {
       const reject = iterator[kLastReject];
-      // Reject if we are waiting for data in the Promise
-      // returned by next() and store the error
+      // Reject if we are waiting for data in the Promise returned by next() and
+      // store the error.
       if (reject !== null) {
         iterator[kLastPromise] = null;
         iterator[kLastResolve] = null;
diff --git a/lib/internal/timers.js b/lib/internal/timers.js
index d485c3ff65a8a5..9a1b0dea0b0dfb 100644
--- a/lib/internal/timers.js
+++ b/lib/internal/timers.js
@@ -154,7 +154,7 @@ function initAsyncResource(resource, type) {
 // Timer constructor function.
 // The entire prototype is defined in lib/timers.js
 function Timeout(callback, after, args, isRepeat) {
-  after *= 1; // coalesce to number or NaN
+  after *= 1; // Coalesce to number or NaN
   if (!(after >= 1 && after <= TIMEOUT_MAX)) {
     if (after > TIMEOUT_MAX) {
       process.emitWarning(`${after} does not fit into` +
diff --git a/lib/internal/trace_events_async_hooks.js b/lib/internal/trace_events_async_hooks.js
index 05bb7b85644915..3b69a85fabf5c7 100644
--- a/lib/internal/trace_events_async_hooks.js
+++ b/lib/internal/trace_events_async_hooks.js
@@ -60,7 +60,7 @@ function createHook() {
 
       trace(kEndEvent, kTraceEventCategory, type, asyncId);
 
-      // cleanup asyncId to type map
+      // Cleanup asyncId to type map
       typeMemory.delete(asyncId);
     }
   });
diff --git a/lib/internal/url.js b/lib/internal/url.js
index 95f0fc21e56c90..9bbd80148cded5 100644
--- a/lib/internal/url.js
+++ b/lib/internal/url.js
@@ -136,7 +136,7 @@ class URLSearchParams {
           throw new ERR_ARG_NOT_ITERABLE('Query pairs');
         }
 
-        // sequence<sequence<USVString>>
+        // Sequence<sequence<USVString>>
         // Note: per spec we have to first exhaust the lists then process them
         const pairs = [];
         for (const pair of init) {
@@ -159,7 +159,7 @@ class URLSearchParams {
           this[searchParams].push(pair[0], pair[1]);
         }
       } else {
-        // record<USVString, USVString>
+        // Record<USVString, USVString>
         // Need to use reflection APIs for full spec compliance.
         this[searchParams] = [];
         const keys = Reflect.ownKeys(init);
@@ -230,7 +230,7 @@ function onParseComplete(flags, protocol, username, password,
   ctx.query = query;
   ctx.fragment = fragment;
   ctx.host = host;
-  if (!this[searchParams]) { // invoked from URL constructor
+  if (!this[searchParams]) { // Invoked from URL constructor
     this[searchParams] = new URLSearchParams();
     this[searchParams][context] = this;
   }
@@ -455,7 +455,7 @@ Object.defineProperties(URL.prototype, {
             try {
               return (new URL(ctx.path[0])).origin;
             } catch {
-              // fall through... do nothing
+              // Fall through... do nothing
             }
           }
           return kOpaqueOrigin;
diff --git a/lib/net.js b/lib/net.js
index 7b4f3f29da84d6..e1a8f1e518f8af 100644
--- a/lib/net.js
+++ b/lib/net.js
@@ -1261,7 +1261,7 @@ function emitErrorNT(self, err) {
 
 
 function emitListeningNT(self) {
-  // ensure handle hasn't closed
+  // Ensure handle hasn't closed
   if (self._handle)
     self.emit('listening');
 }
diff --git a/lib/readline.js b/lib/readline.js
index 4012af8bce6d00..67e71fee4164fc 100644
--- a/lib/readline.js
+++ b/lib/readline.js
@@ -96,7 +96,7 @@ function Interface(input, output, completer, terminal) {
   let prompt = '> ';
 
   if (input && input.input) {
-    // an options object was given
+    // An options object was given
     output = input.output;
     completer = input.completer;
     terminal = input.terminal;
@@ -222,7 +222,7 @@ function Interface(input, output, completer, terminal) {
 
     emitKeypressEvents(input, this);
 
-    // input usually refers to stdin
+    // `input` usually refers to stdin
     input.on('keypress', onkeypress);
     input.on('end', ontermend);
 
@@ -496,7 +496,7 @@ Interface.prototype._tabComplete = function(lastKeypressWasTab) {
     }
 
     const completions = rv[0];
-    const completeOn = rv[1];  // the text that was completed
+    const completeOn = rv[1];  // The text that was completed
     if (completions && completions.length) {
       // Apply/show completions.
       if (lastKeypressWasTab) {
@@ -688,7 +688,7 @@ Interface.prototype._historyNext = function() {
   if (this.historyIndex > 0) {
     this.historyIndex--;
     this.line = this.history[this.historyIndex];
-    this.cursor = this.line.length; // set cursor to end of line.
+    this.cursor = this.line.length; // Set cursor to end of line.
     this._refreshLine();
 
   } else if (this.historyIndex === 0) {
@@ -704,7 +704,7 @@ Interface.prototype._historyPrev = function() {
   if (this.historyIndex + 1 < this.history.length) {
     this.historyIndex++;
     this.line = this.history[this.historyIndex];
-    this.cursor = this.line.length; // set cursor to end of line.
+    this.cursor = this.line.length; // Set cursor to end of line.
 
     this._refreshLine();
   }
@@ -814,7 +814,7 @@ function _ttyWriteDumb(s, key) {
   }
 
   switch (key.name) {
-    case 'return':  // carriage return, i.e. \r
+    case 'return':  // Carriage return, i.e. \r
       this._sawReturnAt = Date.now();
       this._line();
       break;
@@ -837,7 +837,7 @@ function _ttyWriteDumb(s, key) {
   }
 }
 
-// handle a write from the tty
+// Handle a write from the tty
 Interface.prototype._ttyWrite = function(s, key) {
   const previousKey = this._previousKey;
   key = key || {};
@@ -893,11 +893,11 @@ Interface.prototype._ttyWrite = function(s, key) {
         this._deleteLineRight();
         break;
 
-      case 'a': // go to the start of the line
+      case 'a': // Go to the start of the line
         this._moveCursor(-Infinity);
         break;
 
-      case 'e': // go to the end of the line
+      case 'e': // Go to the end of the line
         this._moveCursor(+Infinity);
         break;
 
@@ -905,11 +905,11 @@ Interface.prototype._ttyWrite = function(s, key) {
         this._moveCursor(-charLengthLeft(this.line, this.cursor));
         break;
 
-      case 'f': // forward one character
+      case 'f': // Forward one character
         this._moveCursor(+charLengthAt(this.line, this.cursor));
         break;
 
-      case 'l': // clear the whole screen
+      case 'l': // Clear the whole screen
         cursorTo(this.output, 0, 0);
         clearScreenDown(this.output);
         this._refreshLine();
@@ -919,7 +919,7 @@ Interface.prototype._ttyWrite = function(s, key) {
         this._historyNext();
         break;
 
-      case 'p': // previous history item
+      case 'p': // Previous history item
         this._historyPrev();
         break;
 
@@ -997,7 +997,7 @@ Interface.prototype._ttyWrite = function(s, key) {
       this._sawReturnAt = 0;
 
     switch (key.name) {
-      case 'return':  // carriage return, i.e. \r
+      case 'return':  // Carriage return, i.e. \r
         this._sawReturnAt = Date.now();
         this._line();
         break;
diff --git a/lib/repl.js b/lib/repl.js
index ea4f6ac7e79c52..0ca136023080ee 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -1016,12 +1016,12 @@ function complete(line, callback) {
       if (kill.isFunction)
         tmp[kill.line] = '';
     }
-    var flat = new ArrayStream();         // make a new "input" stream
-    var magic = new REPLServer('', flat); // make a nested REPL
+    var flat = new ArrayStream();         // Make a new "input" stream.
+    var magic = new REPLServer('', flat); // Make a nested REPL.
     replMap.set(magic, replMap.get(this));
-    flat.run(tmp);                        // eval the flattened code
-    // all this is only profitable if the nested REPL
-    // does not have a bufferedCommand
+    flat.run(tmp);                        // `eval` the flattened code.
+    // All this is only profitable if the nested REPL does not have a
+    // bufferedCommand.
     if (!magic[kBufferedCommandSymbol]) {
       magic._domain.on('error', (err) => { throw err; });
       return magic.complete(line, callback);
@@ -1188,7 +1188,7 @@ function complete(line, callback) {
                 // https://github.com/nodejs/node/issues/2119
               }
             }
-            // works for non-objects
+            // Works for non-objects
             try {
               var sentinel = 5;
               var p;
diff --git a/lib/url.js b/lib/url.js
index f50d180c7a1585..edc55c87aaaec7 100644
--- a/lib/url.js
+++ b/lib/url.js
@@ -258,7 +258,7 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
     rest = rest.slice(proto.length);
   }
 
-  // figure out if it's got a host
+  // Figure out if it's got a host
   // user@server is *always* interpreted as a hostname, and url
   // resolution will treat //foo/bar as host=foo,path=bar because that's
   // how the browser resolves relative URLs.
@@ -448,7 +448,7 @@ Url.prototype.parse = function parse(url, parseQueryString, slashesDenoteHost) {
     this.pathname = '/';
   }
 
-  // to support http.request
+  // To support http.request
   if (this.pathname || this.search) {
     const p = this.pathname || '';
     const s = this.search || '';
@@ -746,7 +746,7 @@ Url.prototype.resolveObject = function resolveObject(relative) {
     result.auth = relative.auth;
     result.hostname = relative.hostname || relative.host;
     result.port = relative.port;
-    // to support http.request
+    // To support http.request
     if (result.pathname || result.search) {
       var p = result.pathname || '';
       var s = result.search || '';
@@ -819,7 +819,7 @@ Url.prototype.resolveObject = function resolveObject(relative) {
     result.search = relative.search;
     result.query = relative.query;
   } else if (relative.search !== null && relative.search !== undefined) {
-    // just pull out the search.
+    // Just pull out the search.
     // like href='?foo'.
     // Put this after the other two cases because it simplifies the booleans
     if (noLeadingSlashes) {
@@ -846,8 +846,7 @@ Url.prototype.resolveObject = function resolveObject(relative) {
   }
 
   if (!srcPath.length) {
-    // no path at all.  easy.
-    // we've already handled the other stuff above.
+    // No path at all. All other things were already handled above.
     result.pathname = null;
     // To support http.request
     if (result.search) {
diff --git a/lib/zlib.js b/lib/zlib.js
index 9220b11b0f5971..f598f8b64f0bc5 100644
--- a/lib/zlib.js
+++ b/lib/zlib.js
@@ -555,7 +555,7 @@ function processCallback() {
     self.push(null);
   }
 
-  // finished with the chunk.
+  // Finished with the chunk.
   this.buffer = null;
   this.cb();
 }
diff --git a/test/addons/openssl-client-cert-engine/test.js b/test/addons/openssl-client-cert-engine/test.js
index 6466b0fd9d31ef..1320e7b945d66d 100644
--- a/test/addons/openssl-client-cert-engine/test.js
+++ b/test/addons/openssl-client-cert-engine/test.js
@@ -38,7 +38,7 @@ const server = https.createServer(serverOptions, (req, res) => {
     host: common.localhostIPv4,
     port: server.address().port,
     path: '/test',
-    clientCertEngine: engine,  // engine will provide key+cert
+    clientCertEngine: engine,  // `engine` will provide key+cert
     rejectUnauthorized: false, // Prevent failing on self-signed certificates
     headers: {}
   };
diff --git a/test/async-hooks/test-async-await.js b/test/async-hooks/test-async-await.js
index 8aee59a36ff561..19a22d3076b8c0 100644
--- a/test/async-hooks/test-async-await.js
+++ b/test/async-hooks/test-async-await.js
@@ -12,7 +12,7 @@ const initHooks = require('./init-hooks');
 const util = require('util');
 
 const sleep = util.promisify(setTimeout);
-// either 'inited' or 'resolved'
+// Either 'inited' or 'resolved'
 const promisesInitState = new Map();
 // Either 'before' or 'after' AND asyncId must be present in the other map
 const promisesExecutionState = new Map();
diff --git a/test/async-hooks/test-graph.signal.js b/test/async-hooks/test-graph.signal.js
index c2f889e7b02569..67bf1cf6d8d3ab 100644
--- a/test/async-hooks/test-graph.signal.js
+++ b/test/async-hooks/test-graph.signal.js
@@ -13,7 +13,7 @@ const { exec } = require('child_process');
 const hooks = initHooks();
 
 hooks.enable();
-const interval = setInterval(() => {}, 9999); // keep event loop open
+const interval = setInterval(() => {}, 9999); // Keep event loop open
 process.on('SIGUSR2', common.mustCall(onsigusr2, 2));
 
 let count = 0;
@@ -35,7 +35,7 @@ function onsigusr2() {
 }
 
 function onsigusr2Again() {
-  clearInterval(interval); // let the event loop close
+  clearInterval(interval); // Let the event loop close
 }
 
 process.on('exit', onexit);
diff --git a/test/async-hooks/test-graph.statwatcher.js b/test/async-hooks/test-graph.statwatcher.js
index 3067045d2bf8ac..96376926a67450 100644
--- a/test/async-hooks/test-graph.statwatcher.js
+++ b/test/async-hooks/test-graph.statwatcher.js
@@ -10,16 +10,16 @@ const hooks = initHooks();
 hooks.enable();
 
 function onchange() { }
-// install first file watcher
+// Install first file watcher
 fs.watchFile(__filename, onchange);
 
-// install second file watcher
+// Install second file watcher
 fs.watchFile(commonPath, onchange);
 
-// remove first file watcher
+// Remove first file watcher
 fs.unwatchFile(__filename);
 
-// remove second file watcher
+// Remove second file watcher
 fs.unwatchFile(commonPath);
 
 process.on('exit', onexit);
diff --git a/test/async-hooks/test-immediate.js b/test/async-hooks/test-immediate.js
index 7b51902f77cbeb..fa9475abaed2ef 100644
--- a/test/async-hooks/test-immediate.js
+++ b/test/async-hooks/test-immediate.js
@@ -9,7 +9,7 @@ const { checkInvocations } = require('./hook-checks');
 const hooks = initHooks();
 hooks.enable();
 
-// install first immediate
+// Install first immediate
 setImmediate(common.mustCall(onimmediate));
 
 const as = hooks.activitiesOfTypes('Immediate');
@@ -29,7 +29,7 @@ function onimmediate() {
   checkInvocations(imd1, { init: 1, before: 1 },
                    'imd1: when first set immediate triggered');
 
-  // install second immediate
+  // Install second immediate
   setImmediate(common.mustCall(onimmediateTwo));
   as = hooks.activitiesOfTypes('Immediate');
   assert.strictEqual(as.length, 2);
diff --git a/test/async-hooks/test-statwatcher.js b/test/async-hooks/test-statwatcher.js
index 92832a46803bd4..d67bef26eb1d09 100644
--- a/test/async-hooks/test-statwatcher.js
+++ b/test/async-hooks/test-statwatcher.js
@@ -22,7 +22,7 @@ const hooks = initHooks();
 hooks.enable();
 
 function onchange() {}
-// install first file watcher
+// Install first file watcher
 const w1 = fs.watchFile(file1, { interval: 10 }, onchange);
 
 let as = hooks.activitiesOfTypes('STATWATCHER');
@@ -35,7 +35,7 @@ assert.strictEqual(statwatcher1.triggerAsyncId, 1);
 checkInvocations(statwatcher1, { init: 1 },
                  'watcher1: when started to watch file');
 
-// install second file watcher
+// Install second file watcher
 const w2 = fs.watchFile(file2, { interval: 10 }, onchange);
 as = hooks.activitiesOfTypes('STATWATCHER');
 assert.strictEqual(as.length, 2);
diff --git a/test/async-hooks/test-timers.setTimeout.js b/test/async-hooks/test-timers.setTimeout.js
index 748fa5565eee64..540c88abade3b6 100644
--- a/test/async-hooks/test-timers.setTimeout.js
+++ b/test/async-hooks/test-timers.setTimeout.js
@@ -10,7 +10,7 @@ const TIMEOUT = common.platformTimeout(100);
 const hooks = initHooks();
 hooks.enable();
 
-// install first timeout
+// Install first timeout
 setTimeout(common.mustCall(ontimeout), TIMEOUT);
 const as = hooks.activitiesOfTypes('Timeout');
 assert.strictEqual(as.length, 1);
diff --git a/test/async-hooks/test-ttywrap.readstream.js b/test/async-hooks/test-ttywrap.readstream.js
index bf81a3266c1fb6..e6fb3cdc28a4fe 100644
--- a/test/async-hooks/test-ttywrap.readstream.js
+++ b/test/async-hooks/test-ttywrap.readstream.js
@@ -3,7 +3,7 @@
 const common = require('../common');
 const assert = require('assert');
 
-// general hook test setup
+// General hook test setup
 const tick = require('../common/tick');
 const initHooks = require('./init-hooks');
 const { checkInvocations } = require('./hook-checks');
diff --git a/test/async-hooks/test-ttywrap.writestream.js b/test/async-hooks/test-ttywrap.writestream.js
index 44f32e80f015c2..bcc164c659beed 100644
--- a/test/async-hooks/test-ttywrap.writestream.js
+++ b/test/async-hooks/test-ttywrap.writestream.js
@@ -3,7 +3,7 @@
 const common = require('../common');
 const assert = require('assert');
 
-// general hook test setup
+// General hook test setup
 const tick = require('../common/tick');
 const initHooks = require('./init-hooks');
 const { checkInvocations } = require('./hook-checks');
diff --git a/test/common/index.js b/test/common/index.js
index d6a24dd944f82a..b0e7e0cd115cef 100644
--- a/test/common/index.js
+++ b/test/common/index.js
@@ -795,7 +795,7 @@ module.exports = {
     if (opensslCli !== null) return opensslCli;
 
     if (process.config.variables.node_shared_openssl) {
-      // use external command
+      // Use external command
       opensslCli = 'openssl';
     } else {
       // Use command built from sources included in Node.js repository
diff --git a/test/es-module/test-esm-preserve-symlinks-main.js b/test/es-module/test-esm-preserve-symlinks-main.js
index 38ef5d8fcce6ad..239fdddc2e8d79 100644
--- a/test/es-module/test-esm-preserve-symlinks-main.js
+++ b/test/es-module/test-esm-preserve-symlinks-main.js
@@ -52,6 +52,6 @@ function doTest(flags, done) {
 
 // First test the commonjs module loader
 doTest([], () => {
-  // now test the new loader
+  // Now test the new loader
   doTest(['--experimental-modules'], () => {});
 });
diff --git a/test/js-native-api/test_general/test.js b/test/js-native-api/test_general/test.js
index f0be79085b6658..44b672cdc1f77f 100644
--- a/test/js-native-api/test_general/test.js
+++ b/test/js-native-api/test_general/test.js
@@ -18,12 +18,12 @@ class ExtendedClass extends BaseClass {
 const baseObject = new BaseClass();
 const extendedObject = new ExtendedClass();
 
-// test napi_strict_equals
+// Test napi_strict_equals
 assert.ok(test_general.testStrictEquals(val1, val1));
 assert.strictEqual(test_general.testStrictEquals(val1, val2), false);
 assert.ok(test_general.testStrictEquals(val2, val3));
 
-// test napi_get_prototype
+// Test napi_get_prototype
 assert.strictEqual(test_general.testGetPrototype(baseObject),
                    Object.getPrototypeOf(baseObject));
 assert.strictEqual(test_general.testGetPrototype(extendedObject),
diff --git a/test/js-native-api/test_number/test.js b/test/js-native-api/test_number/test.js
index a7a6009852d884..808d1d9d5c374f 100644
--- a/test/js-native-api/test_number/test.js
+++ b/test/js-native-api/test_number/test.js
@@ -4,7 +4,7 @@ const assert = require('assert');
 const test_number = require(`./build/${common.buildType}/test_number`);
 
 
-// testing api calls for number
+// Testing api calls for number
 function testNumber(num) {
   assert.strictEqual(num, test_number.Test(num));
 }
diff --git a/test/js-native-api/test_string/test.js b/test/js-native-api/test_string/test.js
index 86fdc1640602bc..1be34212a11c3f 100644
--- a/test/js-native-api/test_string/test.js
+++ b/test/js-native-api/test_string/test.js
@@ -2,7 +2,7 @@
 const common = require('../../common');
 const assert = require('assert');
 
-// testing api calls for string
+// Testing api calls for string
 const test_string = require(`./build/${common.buildType}/test_string`);
 
 const empty = '';
diff --git a/test/js-native-api/test_symbol/test1.js b/test/js-native-api/test_symbol/test1.js
index 9232210c46da46..c0a4634c88e898 100644
--- a/test/js-native-api/test_symbol/test1.js
+++ b/test/js-native-api/test_symbol/test1.js
@@ -2,7 +2,7 @@
 const common = require('../../common');
 const assert = require('assert');
 
-// testing api calls for symbol
+// Testing api calls for symbol
 const test_symbol = require(`./build/${common.buildType}/test_symbol`);
 
 const sym = test_symbol.New('test');
diff --git a/test/js-native-api/test_symbol/test2.js b/test/js-native-api/test_symbol/test2.js
index 8bc731b40cb5fe..2060409b9bf8df 100644
--- a/test/js-native-api/test_symbol/test2.js
+++ b/test/js-native-api/test_symbol/test2.js
@@ -2,7 +2,7 @@
 const common = require('../../common');
 const assert = require('assert');
 
-// testing api calls for symbol
+// Testing api calls for symbol
 const test_symbol = require(`./build/${common.buildType}/test_symbol`);
 
 const fooSym = test_symbol.New('foo');
diff --git a/test/js-native-api/test_symbol/test3.js b/test/js-native-api/test_symbol/test3.js
index a7c6c18c025480..445fa3f891954c 100644
--- a/test/js-native-api/test_symbol/test3.js
+++ b/test/js-native-api/test_symbol/test3.js
@@ -2,7 +2,7 @@
 const common = require('../../common');
 const assert = require('assert');
 
-// testing api calls for symbol
+// Testing api calls for symbol
 const test_symbol = require(`./build/${common.buildType}/test_symbol`);
 
 assert.notStrictEqual(test_symbol.New(), test_symbol.New());
diff --git a/test/known_issues/test-vm-ownkeys.js b/test/known_issues/test-vm-ownkeys.js
index 12d3ba7470bf8f..f245b0f7b52a37 100644
--- a/test/known_issues/test-vm-ownkeys.js
+++ b/test/known_issues/test-vm-ownkeys.js
@@ -24,5 +24,5 @@ const ctx = vm.createContext(sandbox);
 const nativeKeys = vm.runInNewContext('Reflect.ownKeys(this);');
 const ownKeys = vm.runInContext('Reflect.ownKeys(this);', ctx);
 const restKeys = ownKeys.filter((key) => !nativeKeys.includes(key));
-// this should not fail
+// This should not fail
 assert.deepStrictEqual(Array.from(restKeys), ['a', 'b', sym1, sym2]);
diff --git a/test/known_issues/test-vm-ownpropertynames.js b/test/known_issues/test-vm-ownpropertynames.js
index cb8184babc8904..d1c03186ab19ee 100644
--- a/test/known_issues/test-vm-ownpropertynames.js
+++ b/test/known_issues/test-vm-ownpropertynames.js
@@ -24,5 +24,5 @@ const ctx = vm.createContext(sandbox);
 const nativeNames = vm.runInNewContext('Object.getOwnPropertyNames(this);');
 const ownNames = vm.runInContext('Object.getOwnPropertyNames(this);', ctx);
 const restNames = ownNames.filter((name) => !nativeNames.includes(name));
-// this should not fail
+// This should not fail
 assert.deepStrictEqual(Array.from(restNames), ['a', 'b']);
diff --git a/test/known_issues/test-vm-ownpropertysymbols.js b/test/known_issues/test-vm-ownpropertysymbols.js
index f11c4999cd463b..2f501627907164 100644
--- a/test/known_issues/test-vm-ownpropertysymbols.js
+++ b/test/known_issues/test-vm-ownpropertysymbols.js
@@ -24,5 +24,5 @@ const ctx = vm.createContext(sandbox);
 const nativeSym = vm.runInNewContext('Object.getOwnPropertySymbols(this);');
 const ownSym = vm.runInContext('Object.getOwnPropertySymbols(this);', ctx);
 const restSym = ownSym.filter((sym) => !nativeSym.includes(sym));
-// this should not fail
+// This should not fail
 assert.deepStrictEqual(Array.from(restSym), [sym1, sym2]);
diff --git a/test/message/throw_custom_error.js b/test/message/throw_custom_error.js
index 7290df53e12420..3e0e6a271c7415 100644
--- a/test/message/throw_custom_error.js
+++ b/test/message/throw_custom_error.js
@@ -22,6 +22,6 @@
 'use strict';
 require('../common');
 
-// custom error throwing
+// Custom error throwing
 // eslint-disable-next-line no-throw-literal
 throw ({ name: 'MyCustomError', message: 'This is a custom message' });
diff --git a/test/message/throw_non_error.js b/test/message/throw_non_error.js
index e7d2f54b85f78f..fc1a568015aaf2 100644
--- a/test/message/throw_non_error.js
+++ b/test/message/throw_non_error.js
@@ -22,6 +22,6 @@
 'use strict';
 require('../common');
 
-// custom error throwing
+// Custom error throwing
 // eslint-disable-next-line no-throw-literal
 throw ({ foo: 'bar' });
diff --git a/test/parallel/test-assert-deep.js b/test/parallel/test-assert-deep.js
index 5b711734780064..3675a18a284fd4 100644
--- a/test/parallel/test-assert-deep.js
+++ b/test/parallel/test-assert-deep.js
@@ -356,7 +356,7 @@ assertNotDeepOrStrict(
   new Map([['1', 5], [0, 5], ['0', 5]])
 );
 
-// undefined value in Map
+// Undefined value in Map
 assertDeepAndStrictEqual(
   new Map([[1, undefined]]),
   new Map([[1, undefined]])
diff --git a/test/parallel/test-buffer-alloc.js b/test/parallel/test-buffer-alloc.js
index ddf2edd896dfb2..8369936b4d8eca 100644
--- a/test/parallel/test-buffer-alloc.js
+++ b/test/parallel/test-buffer-alloc.js
@@ -537,7 +537,7 @@ assert.strictEqual(Buffer.from('A', 'base64').length, 0);
 
 
 {
-  // test an invalid slice end.
+  // Test an invalid slice end.
   const b = Buffer.from([1, 2, 3, 4, 5]);
   const b2 = b.toString('hex', 1, 10000);
   const b3 = b.toString('hex', 1, 5);
@@ -737,7 +737,7 @@ assert.strictEqual(x.inspect(), '<Buffer 81 a3 66 6f 6f a3 62 61 72>');
 }
 
 {
-  // test for buffer overrun
+  // Test for buffer overrun
   const buf = Buffer.from([0, 0, 0, 0, 0]); // length: 5
   const sub = buf.slice(0, 4);         // length: 4
   assert.strictEqual(sub.write('12345', 'latin1'), 4);
@@ -747,7 +747,7 @@ assert.strictEqual(x.inspect(), '<Buffer 81 a3 66 6f 6f a3 62 61 72>');
 }
 
 {
-  // test alloc with fill option
+  // Test alloc with fill option
   const buf = Buffer.alloc(5, '800A', 'hex');
   assert.strictEqual(buf[0], 128);
   assert.strictEqual(buf[1], 10);
diff --git a/test/parallel/test-buffer-compare-offset.js b/test/parallel/test-buffer-compare-offset.js
index 47e5f3041e12e6..8c590f52ed480c 100644
--- a/test/parallel/test-buffer-compare-offset.js
+++ b/test/parallel/test-buffer-compare-offset.js
@@ -48,7 +48,7 @@ assert.strictEqual(a.compare(b, 0, 7, 4, 6), -1);
 // zero length target
 assert.strictEqual(a.compare(b, 0, null), 1);
 
-// coerces to targetEnd == 5
+// Coerces to targetEnd == 5
 assert.strictEqual(a.compare(b, 0, { valueOf: () => 5 }), -1);
 
 // zero length target
diff --git a/test/parallel/test-buffer-copy.js b/test/parallel/test-buffer-copy.js
index b35609743764b3..9810c9824b7b58 100644
--- a/test/parallel/test-buffer-copy.js
+++ b/test/parallel/test-buffer-copy.js
@@ -128,7 +128,7 @@ common.expectsError(
   }
 }
 
-// throw with negative sourceEnd
+// Throw with negative sourceEnd
 common.expectsError(
   () => b.copy(c, 0, -1), errorProperty);
 
diff --git a/test/parallel/test-buffer-includes.js b/test/parallel/test-buffer-includes.js
index 605f988de5c648..5bad445adec524 100644
--- a/test/parallel/test-buffer-includes.js
+++ b/test/parallel/test-buffer-includes.js
@@ -88,7 +88,7 @@ assert.strictEqual(
   true
 );
 
-// test base64 encoding
+// Test base64 encoding
 assert.strictEqual(
   Buffer.from(b.toString('base64'), 'base64')
     .includes('ZA==', 0, 'base64'),
@@ -112,7 +112,7 @@ assert.strictEqual(
   true
 );
 
-// test latin1 encoding
+// Test latin1 encoding
 assert.strictEqual(
   Buffer.from(b.toString('latin1'), 'latin1')
     .includes('d', 0, 'latin1'),
@@ -124,7 +124,7 @@ assert.strictEqual(
   true
 );
 
-// test binary encoding
+// Test binary encoding
 assert.strictEqual(
   Buffer.from(b.toString('binary'), 'binary')
     .includes('d', 0, 'binary'),
diff --git a/test/parallel/test-buffer-indexof.js b/test/parallel/test-buffer-indexof.js
index 44353c127602d8..3f0449ceb084f1 100644
--- a/test/parallel/test-buffer-indexof.js
+++ b/test/parallel/test-buffer-indexof.js
@@ -96,7 +96,7 @@ assert.strictEqual(
   3
 );
 
-// test base64 encoding
+// Test base64 encoding
 assert.strictEqual(
   Buffer.from(b.toString('base64'), 'base64')
     .indexOf('ZA==', 0, 'base64'),
@@ -120,7 +120,7 @@ assert.strictEqual(
   3
 );
 
-// test latin1 encoding
+// Test latin1 encoding
 assert.strictEqual(
   Buffer.from(b.toString('latin1'), 'latin1')
     .indexOf('d', 0, 'latin1'),
@@ -147,7 +147,7 @@ assert.strictEqual(
   0
 );
 
-// test binary encoding
+// Test binary encoding
 assert.strictEqual(
   Buffer.from(b.toString('binary'), 'binary')
     .indexOf('d', 0, 'binary'),
diff --git a/test/parallel/test-buffer-iterator.js b/test/parallel/test-buffer-iterator.js
index 72b775c71313d7..0016b021c078bf 100644
--- a/test/parallel/test-buffer-iterator.js
+++ b/test/parallel/test-buffer-iterator.js
@@ -6,7 +6,7 @@ const buffer = Buffer.from([1, 2, 3, 4, 5]);
 let arr;
 let b;
 
-// buffers should be iterable
+// Buffers should be iterable
 
 arr = [];
 
diff --git a/test/parallel/test-buffer-slow.js b/test/parallel/test-buffer-slow.js
index 1dbc217bdae970..baab6107c4d7f7 100644
--- a/test/parallel/test-buffer-slow.js
+++ b/test/parallel/test-buffer-slow.js
@@ -7,7 +7,7 @@ const SlowBuffer = buffer.SlowBuffer;
 
 const ones = [1, 1, 1, 1];
 
-// should create a Buffer
+// Should create a Buffer
 let sb = SlowBuffer(4);
 assert(sb instanceof Buffer);
 assert.strictEqual(sb.length, 4);
@@ -19,7 +19,7 @@ for (const [key, value] of sb.entries()) {
 // underlying ArrayBuffer should have the same length
 assert.strictEqual(sb.buffer.byteLength, 4);
 
-// should work without new
+// Should work without new
 sb = SlowBuffer(4);
 assert(sb instanceof Buffer);
 assert.strictEqual(sb.length, 4);
@@ -28,7 +28,7 @@ for (const [key, value] of sb.entries()) {
   assert.deepStrictEqual(value, ones[key]);
 }
 
-// should work with edge cases
+// Should work with edge cases
 assert.strictEqual(SlowBuffer(0).length, 0);
 try {
   assert.strictEqual(
diff --git a/test/parallel/test-child-process-constructor.js b/test/parallel/test-child-process-constructor.js
index f0bebd61efc057..9c9ed2d0e84900 100644
--- a/test/parallel/test-child-process-constructor.js
+++ b/test/parallel/test-child-process-constructor.js
@@ -73,7 +73,7 @@ function typeName(value) {
   });
 }
 
-// test that we can call spawn
+// Test that we can call spawn
 const child = new ChildProcess();
 child.spawn({
   file: process.execPath,
diff --git a/test/parallel/test-child-process-disconnect.js b/test/parallel/test-child-process-disconnect.js
index 7ba30b28db3d3e..fb8a2dd0ea2213 100644
--- a/test/parallel/test-child-process-disconnect.js
+++ b/test/parallel/test-child-process-disconnect.js
@@ -80,7 +80,7 @@ if (process.argv[2] === 'child') {
   // The process should also self terminate without using signals
   child.on('exit', common.mustCall());
 
-  // when child is listening
+  // When child is listening
   child.on('message', function(obj) {
     if (obj && obj.msg === 'ready') {
 
@@ -90,7 +90,7 @@ if (process.argv[2] === 'child') {
       socket.on('data', function(data) {
         data = data.toString();
 
-        // ready to be disconnected
+        // Ready to be disconnected
         if (data === 'ready') {
           child.disconnect();
           assert.throws(
@@ -101,7 +101,7 @@ if (process.argv[2] === 'child') {
           return;
         }
 
-        // disconnect is emitted
+        // 'disconnect' is emitted
         childFlag = (data === 'true');
       });
 
diff --git a/test/parallel/test-child-process-exec-error.js b/test/parallel/test-child-process-exec-error.js
index cb8ace0a9bf3e8..eaddeb6614e921 100644
--- a/test/parallel/test-child-process-exec-error.js
+++ b/test/parallel/test-child-process-exec-error.js
@@ -32,9 +32,9 @@ function test(fn, code) {
 }
 
 if (common.isWindows) {
-  test(child_process.exec, 1); // exit code of cmd.exe
+  test(child_process.exec, 1); // Exit code of cmd.exe
 } else {
-  test(child_process.exec, 127); // exit code of /bin/sh
+  test(child_process.exec, 127); // Exit code of /bin/sh
 }
 
 test(child_process.execFile, 'ENOENT');
diff --git a/test/parallel/test-child-process-fork-net-server.js b/test/parallel/test-child-process-fork-net-server.js
index 340b3075f9622a..9d39e149af26f7 100644
--- a/test/parallel/test-child-process-fork-net-server.js
+++ b/test/parallel/test-child-process-fork-net-server.js
@@ -124,7 +124,7 @@ if (process.argv[2] === 'child') {
         }
 
       } else if (msg.what === 'connection') {
-        // child got connection
+        // Child got connection
         connections.done();
       } else if (msg.what === 'close') {
         child.removeListener('message', messageHandlers);
diff --git a/test/parallel/test-child-process-fork-net.js b/test/parallel/test-child-process-fork-net.js
index 90ce482309b98f..6607d7981666de 100644
--- a/test/parallel/test-child-process-fork-net.js
+++ b/test/parallel/test-child-process-fork-net.js
@@ -48,7 +48,7 @@ if (process.argv[2] === 'child') {
       console.error(`[${id}] socket.end ${m}`);
     });
 
-    // store the unfinished socket
+    // Store the unfinished socket
     if (m === 'write') {
       needEnd.push(socket);
     }
diff --git a/test/parallel/test-child-process-spawnsync-input.js b/test/parallel/test-child-process-spawnsync-input.js
index 6e4a22c0e32d97..d1a602460e92fc 100644
--- a/test/parallel/test-child-process-spawnsync-input.js
+++ b/test/parallel/test-child-process-spawnsync-input.js
@@ -29,7 +29,7 @@ const spawnSync = require('child_process').spawnSync;
 const msgOut = 'this is stdout';
 const msgErr = 'this is stderr';
 
-// this is actually not os.EOL?
+// This is actually not os.EOL?
 const msgOutBuf = Buffer.from(`${msgOut}\n`);
 const msgErrBuf = Buffer.from(`${msgErr}\n`);
 
diff --git a/test/parallel/test-child-process-stdio-inherit.js b/test/parallel/test-child-process-stdio-inherit.js
index dfffb70c582016..034a0770168bc9 100644
--- a/test/parallel/test-child-process-stdio-inherit.js
+++ b/test/parallel/test-child-process-stdio-inherit.js
@@ -51,6 +51,6 @@ function grandparent() {
 }
 
 function parent() {
-  // should not immediately exit.
+  // Should not immediately exit.
   spawn('cat', [], { stdio: 'inherit' });
 }
diff --git a/test/parallel/test-cluster-bind-twice.js b/test/parallel/test-cluster-bind-twice.js
index 4ef319ae80d409..7bd818a5e1fe8c 100644
--- a/test/parallel/test-cluster-bind-twice.js
+++ b/test/parallel/test-cluster-bind-twice.js
@@ -102,7 +102,7 @@ if (!id) {
     }));
   }, 2));
 } else {
-  assert(0); // bad command line argument
+  assert(0); // Bad command line argument
 }
 
 function startWorker() {
diff --git a/test/parallel/test-cluster-disconnect.js b/test/parallel/test-cluster-disconnect.js
index 51cbb43c63f5a4..3d1f14257bca59 100644
--- a/test/parallel/test-cluster-disconnect.js
+++ b/test/parallel/test-cluster-disconnect.js
@@ -37,7 +37,7 @@ if (cluster.isWorker) {
   const servers = 2;
   const serverPorts = new Set();
 
-  // test a single TCP server
+  // Test a single TCP server
   const testConnection = (port, cb) => {
     const socket = net.connect(port, '127.0.0.1', () => {
       // buffer result
diff --git a/test/parallel/test-cluster-eaccess.js b/test/parallel/test-cluster-eaccess.js
index 4c2d28429307dc..cf6eae1d38eaa6 100644
--- a/test/parallel/test-cluster-eaccess.js
+++ b/test/parallel/test-cluster-eaccess.js
@@ -66,7 +66,7 @@ if (cluster.isMaster && process.argv.length !== 3) {
     server.on('error', function(err) {
       // Message to child process tells it to exit
       cp.send('end');
-      // propagate error to parent
+      // Propagate error to parent
       process.send(err);
     });
   }));
diff --git a/test/parallel/test-cluster-master-kill.js b/test/parallel/test-cluster-master-kill.js
index 2cc800398147f6..3c22e07edeaad2 100644
--- a/test/parallel/test-cluster-master-kill.js
+++ b/test/parallel/test-cluster-master-kill.js
@@ -26,7 +26,7 @@ const cluster = require('cluster');
 
 if (cluster.isWorker) {
 
-  // keep the worker alive
+  // Keep the worker alive
   const http = require('http');
   http.Server().listen(0, '127.0.0.1');
 
@@ -39,7 +39,7 @@ if (cluster.isWorker) {
     pid: worker.process.pid
   });
 
-  // terminate the cluster process
+  // Terminate the cluster process
   worker.once('listening', common.mustCall(() => {
     setTimeout(() => {
       process.exit(0);
@@ -67,7 +67,7 @@ if (cluster.isWorker) {
     // Make sure that the master died on purpose
     assert.strictEqual(code, 0);
 
-    // check worker process status
+    // Check worker process status
     const pollWorker = () => {
       alive = common.isAlive(pid);
       if (alive) {
diff --git a/test/parallel/test-cluster-worker-exit.js b/test/parallel/test-cluster-worker-exit.js
index ba9c4f8775760e..f93a3f587096ab 100644
--- a/test/parallel/test-cluster-worker-exit.js
+++ b/test/parallel/test-cluster-worker-exit.js
@@ -116,7 +116,7 @@ if (cluster.isWorker) {
   };
 }
 
-// some helper functions ...
+// Some helper functions ...
 
 function checkResults(expected_results, results) {
   for (const k in expected_results) {
diff --git a/test/parallel/test-cluster-worker-kill.js b/test/parallel/test-cluster-worker-kill.js
index 1f2978bdb5b406..0cd6d0321cf670 100644
--- a/test/parallel/test-cluster-worker-kill.js
+++ b/test/parallel/test-cluster-worker-kill.js
@@ -103,7 +103,7 @@ if (cluster.isWorker) {
   });
 }
 
-// some helper functions ...
+// Some helper functions ...
 
 function checkResults(expected_results, results) {
   for (const k in expected_results) {
diff --git a/test/parallel/test-console.js b/test/parallel/test-console.js
index 65e1645f7b1e7b..8f259b7c940b76 100644
--- a/test/parallel/test-console.js
+++ b/test/parallel/test-console.js
@@ -134,7 +134,7 @@ console.dir(custom_inspect, { showHidden: false });
 console.dir({ foo: { bar: { baz: true } } }, { depth: 0 });
 console.dir({ foo: { bar: { baz: true } } }, { depth: 1 });
 
-// test console.dirxml()
+// Test console.dirxml()
 console.dirxml(custom_inspect, custom_inspect);
 console.dirxml(
   { foo: { bar: { baz: true } } },
@@ -142,7 +142,7 @@ console.dirxml(
   { foo: { bar: { quux: true } } }
 );
 
-// test console.trace()
+// Test console.trace()
 console.trace('This is a %j %d', { formatted: 'trace' }, 10, 'foo');
 
 // Test console.time() and console.timeEnd() output
diff --git a/test/parallel/test-crypto-cipher-decipher.js b/test/parallel/test-crypto-cipher-decipher.js
index e7ab8f73b02b0b..ce6ea4e3b81ea4 100644
--- a/test/parallel/test-crypto-cipher-decipher.js
+++ b/test/parallel/test-crypto-cipher-decipher.js
@@ -36,7 +36,7 @@ function testCipher1(key) {
 
   assert.strictEqual(txt, plaintext);
 
-  // streaming cipher interface
+  // Streaming cipher interface
   // NB: In real life, it's not guaranteed that you can get all of it
   // in a single read() like this.  But in this case, we know it's
   // quite small, so there's no harm.
diff --git a/test/parallel/test-crypto-cipheriv-decipheriv.js b/test/parallel/test-crypto-cipheriv-decipheriv.js
index b0ad7a97daab18..d9cc725da1d393 100644
--- a/test/parallel/test-crypto-cipheriv-decipheriv.js
+++ b/test/parallel/test-crypto-cipheriv-decipheriv.js
@@ -23,7 +23,7 @@ function testCipher1(key, iv) {
   assert.strictEqual(txt, plaintext,
                      `encryption/decryption with key ${key} and iv ${iv}`);
 
-  // streaming cipher interface
+  // Streaming cipher interface
   // NB: In real life, it's not guaranteed that you can get all of it
   // in a single read() like this.  But in this case, we know it's
   // quite small, so there's no harm.
diff --git a/test/parallel/test-crypto-dh.js b/test/parallel/test-crypto-dh.js
index 5a63667c995b09..ead77d6a30c811 100644
--- a/test/parallel/test-crypto-dh.js
+++ b/test/parallel/test-crypto-dh.js
@@ -230,7 +230,7 @@ if (availableCurves.has('prime256v1') && availableCurves.has('secp256k1')) {
   assert(firstByte === 2 || firstByte === 3);
   firstByte = ecdh1.getPublicKey('buffer', 'hybrid')[0];
   assert(firstByte === 6 || firstByte === 7);
-  // format value should be string
+  // Format value should be string
 
   common.expectsError(
     () => ecdh1.getPublicKey('buffer', 10),
diff --git a/test/parallel/test-crypto-keygen.js b/test/parallel/test-crypto-keygen.js
index 7a164dffe9059b..64964cc7aedf7d 100644
--- a/test/parallel/test-crypto-keygen.js
+++ b/test/parallel/test-crypto-keygen.js
@@ -606,7 +606,7 @@ const sec1EncExp = (cipher) => getRegExpForPEM('EC PRIVATE KEY', cipher);
     });
   }
 
-  // cipher of invalid type.
+  // Cipher of invalid type.
   for (const cipher of [0, true, {}]) {
     common.expectsError(() => generateKeyPairSync('rsa', {
       modulusLength: 4096,
diff --git a/test/parallel/test-crypto-padding-aes256.js b/test/parallel/test-crypto-padding-aes256.js
index d6c395f0a42d35..14d853bdfd0a5d 100644
--- a/test/parallel/test-crypto-padding-aes256.js
+++ b/test/parallel/test-crypto-padding-aes256.js
@@ -46,7 +46,7 @@ function decrypt(val, pad) {
 // echo 0123456789abcdef0123456789abcdef \
 // | openssl enc -e -aes256 -nopad -K <key> -iv <iv> \
 // | openssl enc -d -aes256 -nopad -K <key> -iv <iv>
-let plaintext = '0123456789abcdef0123456789abcdef'; // multiple of block size
+let plaintext = '0123456789abcdef0123456789abcdef'; // Multiple of block size
 let encrypted = encrypt(plaintext, false);
 let decrypted = decrypt(encrypted, false);
 assert.strictEqual(decrypted, plaintext);
diff --git a/test/parallel/test-crypto-scrypt.js b/test/parallel/test-crypto-scrypt.js
index 55b5aeaf8ff06b..e1d0ddf10c98f4 100644
--- a/test/parallel/test-crypto-scrypt.js
+++ b/test/parallel/test-crypto-scrypt.js
@@ -97,9 +97,9 @@ const good = [
 const bad = [
   { N: 1, p: 1, r: 1 },         // N < 2
   { N: 3, p: 1, r: 1 },         // Not power of 2.
-  { N: 1, cost: 1 },            // both N and cost
-  { p: 1, parallelization: 1 }, // both p and parallelization
-  { r: 1, blockSize: 1 }        // both r and blocksize
+  { N: 1, cost: 1 },            // Both N and cost
+  { p: 1, parallelization: 1 }, // Both p and parallelization
+  { r: 1, blockSize: 1 }        // Both r and blocksize
 ];
 
 // Test vectors where 128*N*r exceeds maxmem.
diff --git a/test/parallel/test-debugger-pid.js b/test/parallel/test-debugger-pid.js
index e11d23152f7057..f269ff310b145c 100644
--- a/test/parallel/test-debugger-pid.js
+++ b/test/parallel/test-debugger-pid.js
@@ -6,7 +6,7 @@ const spawn = require('child_process').spawn;
 
 let buffer = '';
 
-// connect to debug agent
+// Connect to debug agent
 const interfacer = spawn(process.execPath, ['debug', '-p', '655555']);
 
 interfacer.stdout.setEncoding('utf-8');
diff --git a/test/parallel/test-dgram-bind.js b/test/parallel/test-dgram-bind.js
index 0b8447c3115da1..e3b358bdd2f1f5 100644
--- a/test/parallel/test-dgram-bind.js
+++ b/test/parallel/test-dgram-bind.js
@@ -38,6 +38,6 @@ socket.on('listening', common.mustCall(() => {
   socket.close();
 }));
 
-const result = socket.bind(); // should not throw
+const result = socket.bind(); // Should not throw.
 
-assert.strictEqual(result, socket); // should have returned itself
+assert.strictEqual(result, socket); // Should have returned itself.
diff --git a/test/parallel/test-dgram-close-in-listening.js b/test/parallel/test-dgram-close-in-listening.js
index 16432d85d6f345..ae3ab71d7e2cff 100644
--- a/test/parallel/test-dgram-close-in-listening.js
+++ b/test/parallel/test-dgram-close-in-listening.js
@@ -13,7 +13,7 @@ socket.on('listening', function() {
   socket.close();
 });
 
-// get a random port for send
+// Get a random port for send
 const portGetter = dgram.createSocket('udp4')
   .bind(0, 'localhost', common.mustCall(() => {
     // Adds a listener to 'listening' to send the data when
diff --git a/test/parallel/test-dgram-close-is-not-callback.js b/test/parallel/test-dgram-close-is-not-callback.js
index 69c166f42f3151..bfb0bcd2bb86d4 100644
--- a/test/parallel/test-dgram-close-is-not-callback.js
+++ b/test/parallel/test-dgram-close-is-not-callback.js
@@ -6,7 +6,7 @@ const buf = Buffer.alloc(1024, 42);
 
 const socket = dgram.createSocket('udp4');
 
-// get a random port for send
+// Get a random port for send
 const portGetter = dgram.createSocket('udp4')
   .bind(0, 'localhost', common.mustCall(() => {
     socket.send(buf, 0, buf.length,
diff --git a/test/parallel/test-dgram-close.js b/test/parallel/test-dgram-close.js
index 7b49cee73bed6a..3a91069c306efa 100644
--- a/test/parallel/test-dgram-close.js
+++ b/test/parallel/test-dgram-close.js
@@ -34,7 +34,7 @@ const buf = Buffer.alloc(1024, 42);
 let socket = dgram.createSocket('udp4');
 const { handle } = socket[kStateSymbol];
 
-// get a random port for send
+// Get a random port for send
 const portGetter = dgram.createSocket('udp4')
   .bind(0, 'localhost', common.mustCall(() => {
     socket.send(buf, 0, buf.length,
diff --git a/test/parallel/test-file-write-stream2.js b/test/parallel/test-file-write-stream2.js
index 5e18ad44ae7dfa..2654c8bca20712 100644
--- a/test/parallel/test-file-write-stream2.js
+++ b/test/parallel/test-file-write-stream2.js
@@ -106,7 +106,7 @@ for (let i = 0; i < 11; i++) {
   const ret = file.write(String(i));
   console.error(`${i} ${ret}`);
 
-  // return false when i hits 10
+  // Return false when i hits 10
   assert.strictEqual(ret, i !== 10);
 }
 cb_occurred += 'write ';
diff --git a/test/parallel/test-fs-error-messages.js b/test/parallel/test-fs-error-messages.js
index 370b4f46977a20..05e4515ad40abd 100644
--- a/test/parallel/test-fs-error-messages.js
+++ b/test/parallel/test-fs-error-messages.js
@@ -190,7 +190,7 @@ function re(literals, ...values) {
   );
 }
 
-// link nonexistent file
+// Link nonexistent file
 {
   const validateError = (err) => {
     assert.strictEqual(nonexistentFile, err.path);
@@ -308,7 +308,7 @@ function re(literals, ...values) {
   );
 }
 
-// rename non-empty directory
+// Rename non-empty directory
 {
   const validateError = (err) => {
     assert.strictEqual(existingDir, err.path);
diff --git a/test/parallel/test-fs-mkdir.js b/test/parallel/test-fs-mkdir.js
index 2a15627a0f1767..9bd2df180112f0 100644
--- a/test/parallel/test-fs-mkdir.js
+++ b/test/parallel/test-fs-mkdir.js
@@ -98,7 +98,7 @@ function nextdir() {
   const pathname = path.join(tmpdir.path, nextdir(), nextdir());
 
   fs.mkdirSync(pathname, { recursive: true });
-  // should not cause an error.
+  // Should not cause an error.
   fs.mkdirSync(pathname, { recursive: true });
 
   const exists = fs.existsSync(pathname);
@@ -143,7 +143,7 @@ function nextdir() {
   }));
 }
 
-// mkdirp when path is a file.
+// `mkdirp` when path is a file.
 {
   const pathname = path.join(tmpdir.path, nextdir(), nextdir());
 
diff --git a/test/parallel/test-fs-promises.js b/test/parallel/test-fs-promises.js
index 2e6ba0e8a24985..c12b0135191821 100644
--- a/test/parallel/test-fs-promises.js
+++ b/test/parallel/test-fs-promises.js
@@ -143,7 +143,7 @@ async function getHandle(dest) {
       assert.deepStrictEqual((await readFile(dest)).toString(), 'hello');
     }
 
-    // invalid change of ownership
+    // Invalid change of ownership
     {
       const handle = await getHandle(dest);
 
@@ -181,7 +181,7 @@ async function getHandle(dest) {
         });
     }
 
-    // set modification times
+    // Set modification times
     {
       const handle = await getHandle(dest);
 
@@ -271,7 +271,7 @@ async function getHandle(dest) {
       await unlink(newFile);
     }
 
-    // mkdir when options is number.
+    // `mkdir` when options is number.
     {
       const dir = path.join(tmpDir, nextdir());
       await mkdir(dir, 777);
@@ -279,7 +279,7 @@ async function getHandle(dest) {
       assert(stats.isDirectory());
     }
 
-    // mkdir when options is string.
+    // `mkdir` when options is string.
     {
       const dir = path.join(tmpDir, nextdir());
       await mkdir(dir, '777');
@@ -295,7 +295,7 @@ async function getHandle(dest) {
       assert(stats.isDirectory());
     }
 
-    // mkdirp when path is a file.
+    // `mkdirp` when path is a file.
     {
       const dir = path.join(tmpDir, nextdir(), nextdir());
       await mkdir(path.dirname(dir));
diff --git a/test/parallel/test-fs-realpath-on-substed-drive.js b/test/parallel/test-fs-realpath-on-substed-drive.js
index 1c86dc364974dc..d5c684f33c073f 100644
--- a/test/parallel/test-fs-realpath-on-substed-drive.js
+++ b/test/parallel/test-fs-realpath-on-substed-drive.js
@@ -12,7 +12,7 @@ const spawnSync = require('child_process').spawnSync;
 
 let result;
 
-// create a subst drive
+// Create a subst drive
 const driveLetters = 'ABCDEFGHIJKLMNOPQRSTUWXYZ';
 let drive;
 let i;
diff --git a/test/parallel/test-fs-realpath.js b/test/parallel/test-fs-realpath.js
index 48294d4a62e0ec..d12c8a28d2a69b 100644
--- a/test/parallel/test-fs-realpath.js
+++ b/test/parallel/test-fs-realpath.js
@@ -41,7 +41,7 @@ tmpdir.refresh();
 let root = '/';
 let assertEqualPath = assert.strictEqual;
 if (common.isWindows) {
-  // something like "C:\\"
+  // Something like "C:\\"
   root = process.cwd().substr(0, 3);
   assertEqualPath = function(path_left, path_right, message) {
     assert
diff --git a/test/parallel/test-http-agent-getname.js b/test/parallel/test-http-agent-getname.js
index 31dc255ba558db..ab946a4bde3ddf 100644
--- a/test/parallel/test-http-agent-getname.js
+++ b/test/parallel/test-http-agent-getname.js
@@ -9,7 +9,7 @@ const tmpdir = require('../common/tmpdir');
 
 const agent = new http.Agent();
 
-// default to localhost
+// Default to localhost
 assert.strictEqual(
   agent.getName({
     port: 80,
diff --git a/test/parallel/test-http-agent-keepalive.js b/test/parallel/test-http-agent-keepalive.js
index 7e2cef4e3e7ee6..5902c5867968cf 100644
--- a/test/parallel/test-http-agent-keepalive.js
+++ b/test/parallel/test-http-agent-keepalive.js
@@ -119,7 +119,7 @@ function remoteError() {
 
 server.listen(0, common.mustCall(() => {
   name = `localhost:${server.address().port}:`;
-  // request first, and keep alive
+  // Request first, and keep alive
   get('/first', common.mustCall((res) => {
     assert.strictEqual(res.statusCode, 200);
     res.on('data', checkDataAndSockets);
diff --git a/test/parallel/test-http-client-override-global-agent.js b/test/parallel/test-http-client-override-global-agent.js
index c36c9d26a8dd63..f046abaa74e45d 100644
--- a/test/parallel/test-http-client-override-global-agent.js
+++ b/test/parallel/test-http-client-override-global-agent.js
@@ -14,7 +14,7 @@ server.listen(0, common.mustCall(() => {
   http.globalAgent = agent;
 
   makeRequest();
-  assert(agent.sockets.hasOwnProperty(name)); // agent has indeed been used
+  assert(agent.sockets.hasOwnProperty(name)); // Agent has indeed been used
 }));
 
 function makeRequest() {
diff --git a/test/parallel/test-http-client-timeout-agent.js b/test/parallel/test-http-client-timeout-agent.js
index 154f788c188f9d..66c0c0f6b917e8 100644
--- a/test/parallel/test-http-client-timeout-agent.js
+++ b/test/parallel/test-http-client-timeout-agent.js
@@ -36,7 +36,7 @@ const server = http.createServer((req, res) => {
   const m = /\/(.*)/.exec(req.url);
   const reqid = parseInt(m[1], 10);
   if (reqid % 2) {
-    // do not reply the request
+    // Do not reply the request
   } else {
     res.writeHead(200, { 'Content-Type': 'text/plain' });
     res.write(reqid.toString());
diff --git a/test/parallel/test-http-many-ended-pipelines.js b/test/parallel/test-http-many-ended-pipelines.js
index d17090cec918a0..eb6f1341c55927 100644
--- a/test/parallel/test-http-many-ended-pipelines.js
+++ b/test/parallel/test-http-many-ended-pipelines.js
@@ -22,7 +22,7 @@
 'use strict';
 require('../common');
 
-// no warnings should happen!
+// No warnings should happen!
 const trace = console.trace;
 console.trace = function() {
   trace.apply(console, arguments);
diff --git a/test/parallel/test-http-outgoing-internal-headers.js b/test/parallel/test-http-outgoing-internal-headers.js
index 2cebfe9e2b966a..13bb8efc29011c 100644
--- a/test/parallel/test-http-outgoing-internal-headers.js
+++ b/test/parallel/test-http-outgoing-internal-headers.js
@@ -10,14 +10,14 @@ const warn = 'OutgoingMessage.prototype._headers is deprecated';
 common.expectWarning('DeprecationWarning', warn, 'DEP0066');
 
 {
-  // tests for _headers get method
+  // Tests for _headers get method
   const outgoingMessage = new OutgoingMessage();
   outgoingMessage.getHeaders = common.mustCall();
   outgoingMessage._headers;
 }
 
 {
-  // tests for _headers set method
+  // Tests for _headers set method
   const outgoingMessage = new OutgoingMessage();
   outgoingMessage._headers = {
     host: 'risingstack.com',
diff --git a/test/parallel/test-http-res-write-end-dont-take-array.js b/test/parallel/test-http-res-write-end-dont-take-array.js
index d7000f6fd2d42c..8bebfc14e4bc2d 100644
--- a/test/parallel/test-http-res-write-end-dont-take-array.js
+++ b/test/parallel/test-http-res-write-end-dont-take-array.js
@@ -30,9 +30,9 @@ server.once('request', common.mustCall((req, res) => {
   server.on('request', common.mustCall((req, res) => {
     res.end(Buffer.from('asdf'));
   }));
-  // write should accept string
+  // `res.write()` should accept `string`.
   res.write('string');
-  // write should accept buffer
+  // `res.write()` should accept `buffer`.
   res.write(Buffer.from('asdf'));
 
   const expectedError = {
@@ -40,7 +40,7 @@ server.once('request', common.mustCall((req, res) => {
     name: 'TypeError',
   };
 
-  // Write should not accept an Array
+  // `res.write()` should not accept an Array.
   assert.throws(
     () => {
       res.write(['array']);
@@ -48,7 +48,7 @@ server.once('request', common.mustCall((req, res) => {
     expectedError
   );
 
-  // End should not accept an Array
+  // `res.end()` should not accept an Array.
   assert.throws(
     () => {
       res.end(['moo']);
@@ -56,12 +56,12 @@ server.once('request', common.mustCall((req, res) => {
     expectedError
   );
 
-  // end should accept string
+  // `res.end()` should accept `string`.
   res.end('string');
 }));
 
 server.listen(0, function() {
-  // Just make a request, other tests handle responses
+  // Just make a request, other tests handle responses.
   http.get({ port: this.address().port }, (res) => {
     res.resume();
     // Do it again to test .end(Buffer);
diff --git a/test/parallel/test-http-set-cookies.js b/test/parallel/test-http-set-cookies.js
index 7a57523b04af9c..613da4742aea4d 100644
--- a/test/parallel/test-http-set-cookies.js
+++ b/test/parallel/test-http-set-cookies.js
@@ -59,7 +59,7 @@ server.on('listening', function() {
     });
   });
 
-  // two set-cookie headers
+  // Two set-cookie headers
 
   http.get({ port: this.address().port, path: '/two' }, function(res) {
     assert.deepStrictEqual(res.headers['set-cookie'], ['A', 'B']);
diff --git a/test/parallel/test-http-slow-headers-keepalive.js b/test/parallel/test-http-slow-headers-keepalive.js
index 5552f33f77e3c2..4e62b59168326e 100644
--- a/test/parallel/test-http-slow-headers-keepalive.js
+++ b/test/parallel/test-http-slow-headers-keepalive.js
@@ -33,7 +33,7 @@ server.once('timeout', common.mustCall((socket) => {
 server.listen(0, () => {
   const client = net.connect(server.address().port);
   client.write(headers);
-  // finish the first request
+  // Finish the first request
   client.write('\r\n');
   // second request
   client.write(headers);
diff --git a/test/parallel/test-http-url.parse-auth-with-header-in-request.js b/test/parallel/test-http-url.parse-auth-with-header-in-request.js
index 7a9a486bcc5dde..ea5793ee18aef5 100644
--- a/test/parallel/test-http-url.parse-auth-with-header-in-request.js
+++ b/test/parallel/test-http-url.parse-auth-with-header-in-request.js
@@ -31,7 +31,7 @@ function check(request) {
 }
 
 const server = http.createServer(function(request, response) {
-  // run the check function
+  // Run the check function
   check(request);
   response.writeHead(200, {});
   response.end('ok');
diff --git a/test/parallel/test-http-url.parse-auth.js b/test/parallel/test-http-url.parse-auth.js
index ac09c0e1b84216..2bb531158645a0 100644
--- a/test/parallel/test-http-url.parse-auth.js
+++ b/test/parallel/test-http-url.parse-auth.js
@@ -31,7 +31,7 @@ function check(request) {
 }
 
 const server = http.createServer(function(request, response) {
-  // run the check function
+  // Run the check function
   check(request);
   response.writeHead(200, {});
   response.end('ok');
diff --git a/test/parallel/test-http-url.parse-basic.js b/test/parallel/test-http-url.parse-basic.js
index e03f39aa9035eb..71885b4bd08949 100644
--- a/test/parallel/test-http-url.parse-basic.js
+++ b/test/parallel/test-http-url.parse-basic.js
@@ -27,7 +27,7 @@ const url = require('url');
 
 let testURL;
 
-// make sure the basics work
+// Make sure the basics work
 function check(request) {
   // Default method should still be 'GET'
   assert.strictEqual(request.method, 'GET');
@@ -39,7 +39,7 @@ function check(request) {
 }
 
 const server = http.createServer(function(request, response) {
-  // run the check function
+  // Run the check function
   check(request);
   response.writeHead(200, {});
   response.end('ok');
diff --git a/test/parallel/test-http-url.parse-https.request.js b/test/parallel/test-http-url.parse-https.request.js
index 6ca9e51e826859..2f18899176e73d 100644
--- a/test/parallel/test-http-url.parse-https.request.js
+++ b/test/parallel/test-http-url.parse-https.request.js
@@ -36,12 +36,12 @@ const httpsOptions = {
 };
 
 function check(request) {
-  // assert that I'm https
+  // Assert that I'm https
   assert.ok(request.socket._secureEstablished);
 }
 
 const server = https.createServer(httpsOptions, function(request, response) {
-  // run the check function
+  // Run the check function
   check(request);
   response.writeHead(200, {});
   response.end('ok');
diff --git a/test/parallel/test-http-url.parse-path.js b/test/parallel/test-http-url.parse-path.js
index 4cc5fbf48e015d..25e4838c4afaf6 100644
--- a/test/parallel/test-http-url.parse-path.js
+++ b/test/parallel/test-http-url.parse-path.js
@@ -26,12 +26,12 @@ const http = require('http');
 const url = require('url');
 
 function check(request) {
-  // a path should come over
+  // A path should come over
   assert.strictEqual(request.url, '/asdf');
 }
 
 const server = http.createServer(function(request, response) {
-  // run the check function
+  // Run the check function
   check(request);
   response.writeHead(200, {});
   response.end('ok');
diff --git a/test/parallel/test-http-url.parse-post.js b/test/parallel/test-http-url.parse-post.js
index 91a567d1560f1a..db5ee78fe6ebe2 100644
--- a/test/parallel/test-http-url.parse-post.js
+++ b/test/parallel/test-http-url.parse-post.js
@@ -38,7 +38,7 @@ function check(request) {
 }
 
 const server = http.createServer(function(request, response) {
-  // run the check function
+  // Run the check function
   check(request);
   response.writeHead(200, {});
   response.end('ok');
diff --git a/test/parallel/test-http-url.parse-search.js b/test/parallel/test-http-url.parse-search.js
index d10713f5f1a7cb..0759c779d3ffb0 100644
--- a/test/parallel/test-http-url.parse-search.js
+++ b/test/parallel/test-http-url.parse-search.js
@@ -31,7 +31,7 @@ function check(request) {
 }
 
 const server = http.createServer(function(request, response) {
-  // run the check function
+  // Run the check function
   check(request);
   response.writeHead(200, {});
   response.end('ok');
diff --git a/test/parallel/test-http-write-callbacks.js b/test/parallel/test-http-write-callbacks.js
index a4f23e12cb955b..3730e57936b4a6 100644
--- a/test/parallel/test-http-write-callbacks.js
+++ b/test/parallel/test-http-write-callbacks.js
@@ -51,7 +51,7 @@ server.on('checkContinue', (req, res) => {
   server.close();
   assert.strictEqual(req.method, 'PUT');
   res.writeContinue(() => {
-    // continue has been written
+    // Continue has been written
     req.on('end', () => {
       res.write('asdf', (er) => {
         assert.ifError(er);
diff --git a/test/parallel/test-http2-binding.js b/test/parallel/test-http2-binding.js
index 8c2826e5fb4b6e..82eafc0de946ff 100644
--- a/test/parallel/test-http2-binding.js
+++ b/test/parallel/test-http2-binding.js
@@ -22,7 +22,7 @@ assert.strictEqual(settings.maxFrameSize, 16384);
 assert.strictEqual(binding.nghttp2ErrorString(-517),
                    'GOAWAY has already been sent');
 
-// assert constants are present
+// Assert constants are present
 assert(binding.constants);
 assert.strictEqual(typeof binding.constants, 'object');
 const constants = binding.constants;
diff --git a/test/parallel/test-http2-client-destroy.js b/test/parallel/test-http2-client-destroy.js
index e7ea37e1528ef6..fe2c9591c7017d 100644
--- a/test/parallel/test-http2-client-destroy.js
+++ b/test/parallel/test-http2-client-destroy.js
@@ -100,7 +100,7 @@ const Countdown = require('../common/countdown');
   }));
 }
 
-// test destroy before goaway
+// Test destroy before goaway
 {
   const server = h2.createServer();
   server.on('stream', common.mustCall((stream) => {
@@ -120,7 +120,7 @@ const Countdown = require('../common/countdown');
   }));
 }
 
-// test destroy before connect
+// Test destroy before connect
 {
   const server = h2.createServer();
   server.on('stream', common.mustNotCall());
@@ -138,7 +138,7 @@ const Countdown = require('../common/countdown');
   }));
 }
 
-// test close before connect
+// Test close before connect
 {
   const server = h2.createServer();
 
@@ -151,7 +151,7 @@ const Countdown = require('../common/countdown');
     }));
 
     const req = client.request();
-    // should throw goaway error
+    // Should throw goaway error
     req.on('error', common.expectsError({
       code: 'ERR_HTTP2_GOAWAY_SESSION',
       type: Error,
diff --git a/test/parallel/test-http2-client-socket-destroy.js b/test/parallel/test-http2-client-socket-destroy.js
index a91c6da28d1813..2cc6ef1e4ea4a8 100644
--- a/test/parallel/test-http2-client-socket-destroy.js
+++ b/test/parallel/test-http2-client-socket-destroy.js
@@ -19,7 +19,7 @@ server.on('stream', common.mustCall((stream) => {
   stream.on('close', common.mustCall());
   stream.respond();
   stream.write(body);
-  // purposefully do not end()
+  // Purposefully do not end()
 }));
 
 server.listen(0, common.mustCall(function() {
@@ -27,7 +27,7 @@ server.listen(0, common.mustCall(function() {
   const req = client.request();
 
   req.on('response', common.mustCall(() => {
-    // send a premature socket close
+    // Send a premature socket close
     client[kSocket].destroy();
   }));
 
diff --git a/test/parallel/test-http2-compat-serverresponse-end.js b/test/parallel/test-http2-compat-serverresponse-end.js
index e7972c2fe01a9f..e0a49ca23a45f1 100644
--- a/test/parallel/test-http2-compat-serverresponse-end.js
+++ b/test/parallel/test-http2-compat-serverresponse-end.js
@@ -166,7 +166,7 @@ const {
       const request = client.request(headers);
       request.on('response', mustCall((headers, flags) => {
         strictEqual(headers[HTTP2_HEADER_STATUS], HTTP_STATUS_OK);
-        strictEqual(flags, 5); // the end of stream flag is set
+        strictEqual(flags, 5); // The end of stream flag is set
         strictEqual(headers.foo, 'bar');
       }));
       request.on('data', mustNotCall());
@@ -231,7 +231,7 @@ const {
       const request = client.request(headers);
       request.on('response', mustCall((headers, flags) => {
         strictEqual(headers[HTTP2_HEADER_STATUS], HTTP_STATUS_OK);
-        strictEqual(flags, 5); // the end of stream flag is set
+        strictEqual(flags, 5); // The end of stream flag is set
         strictEqual(headers.foo, 'bar');
       }));
       request.on('data', mustNotCall());
@@ -266,7 +266,7 @@ const {
       const request = client.request(headers);
       request.on('response', mustCall((headers, flags) => {
         strictEqual(headers[HTTP2_HEADER_STATUS], HTTP_STATUS_OK);
-        strictEqual(flags, 5); // the end of stream flag is set
+        strictEqual(flags, 5); // The end of stream flag is set
         strictEqual(headers.foo, 'bar');
       }));
       request.on('data', mustNotCall());
@@ -306,7 +306,7 @@ const {
       const request = client.request(headers);
       request.on('response', mustCall((headers, flags) => {
         strictEqual(headers[HTTP2_HEADER_STATUS], HTTP_STATUS_OK);
-        strictEqual(flags, 5); // the end of stream flag is set
+        strictEqual(flags, 5); // The end of stream flag is set
         strictEqual(headers.foo, 'bar');
       }));
       request.on('data', mustNotCall());
@@ -339,7 +339,7 @@ const {
       const request = client.request(headers);
       request.on('response', mustCall((headers, flags) => {
         strictEqual(headers[HTTP2_HEADER_STATUS], HTTP_STATUS_OK);
-        strictEqual(flags, 5); // the end of stream flag is set
+        strictEqual(flags, 5); // The end of stream flag is set
       }));
       request.on('data', mustNotCall());
       request.on('end', mustCall(() => {
diff --git a/test/parallel/test-http2-compat-serverresponse-flushheaders.js b/test/parallel/test-http2-compat-serverresponse-flushheaders.js
index d155b07863d26c..6927b3754b1eb3 100644
--- a/test/parallel/test-http2-compat-serverresponse-flushheaders.js
+++ b/test/parallel/test-http2-compat-serverresponse-flushheaders.js
@@ -15,7 +15,7 @@ server.listen(0, common.mustCall(function() {
   const port = server.address().port;
   server.once('request', common.mustCall(function(request, response) {
     assert.strictEqual(response.headersSent, false);
-    assert.strictEqual(response._header, false); // alias for headersSent
+    assert.strictEqual(response._header, false); // Alias for headersSent
     response.flushHeaders();
     assert.strictEqual(response.headersSent, true);
     assert.strictEqual(response._header, true);
diff --git a/test/parallel/test-http2-compat-write-head-destroyed.js b/test/parallel/test-http2-compat-write-head-destroyed.js
index 4576119ee7d435..842bf0e9abffb0 100644
--- a/test/parallel/test-http2-compat-write-head-destroyed.js
+++ b/test/parallel/test-http2-compat-write-head-destroyed.js
@@ -8,7 +8,7 @@ const http2 = require('http2');
 // Check that writeHead, write and end do not crash in compatibility mode
 
 const server = http2.createServer(common.mustCall((req, res) => {
-  // destroy the stream first
+  // Destroy the stream first
   req.stream.destroy();
 
   res.writeHead(200);
diff --git a/test/parallel/test-http2-connect.js b/test/parallel/test-http2-connect.js
index bef4ff79604ada..a2f30f974e9329 100644
--- a/test/parallel/test-http2-connect.js
+++ b/test/parallel/test-http2-connect.js
@@ -55,7 +55,7 @@ const { connect: netConnect } = require('net');
   }));
 }
 
-// check for https as protocol
+// Check for https as protocol
 {
   const authority = 'https://localhost';
   // A socket error may or may not be reported, keep this as a non-op
diff --git a/test/parallel/test-http2-head-request.js b/test/parallel/test-http2-head-request.js
index a56abf3c9006f3..c8103e7190c3fa 100644
--- a/test/parallel/test-http2-head-request.js
+++ b/test/parallel/test-http2-head-request.js
@@ -49,7 +49,7 @@ server.listen(0, () => {
 
   req.on('response', common.mustCall((headers, flags) => {
     assert.strictEqual(headers[HTTP2_HEADER_STATUS], 200);
-    assert.strictEqual(flags, 5); // the end of stream flag is set
+    assert.strictEqual(flags, 5); // The end of stream flag is set
   }));
   req.on('data', common.mustNotCall());
   req.on('end', common.mustCall(() => {
diff --git a/test/parallel/test-http2-session-settings.js b/test/parallel/test-http2-session-settings.js
index 6061808082519d..46ba1753e2da41 100644
--- a/test/parallel/test-http2-session-settings.js
+++ b/test/parallel/test-http2-session-settings.js
@@ -101,7 +101,7 @@ server.listen(
         );
       });
 
-      // error checks for enablePush
+      // Error checks for enablePush
       [1, {}, 'test', [], null, Infinity, NaN].forEach((i) => {
         common.expectsError(
           () => client.settings({ enablePush: i }),
diff --git a/test/parallel/test-http2-session-unref.js b/test/parallel/test-http2-session-unref.js
index 0381971c0eace5..dcfbccf215aec8 100644
--- a/test/parallel/test-http2-session-unref.js
+++ b/test/parallel/test-http2-session-unref.js
@@ -35,7 +35,7 @@ server.listen(0, common.mustCall(() => {
     client.unref();
   }
 
-  // unref destroyed client
+  // Unref destroyed client
   {
     const client = http2.connect(`http://localhost:${port}`);
 
@@ -45,7 +45,7 @@ server.listen(0, common.mustCall(() => {
     }));
   }
 
-  // unref destroyed client
+  // Unref destroyed client
   {
     const client = http2.connect(`http://localhost:${port}`, {
       createConnection: common.mustCall(() => clientSide)
diff --git a/test/parallel/test-https-agent-create-connection.js b/test/parallel/test-https-agent-create-connection.js
index c0b50cef01abe4..1bb3da5f1e1501 100644
--- a/test/parallel/test-https-agent-create-connection.js
+++ b/test/parallel/test-https-agent-create-connection.js
@@ -59,7 +59,7 @@ function createServer() {
   }));
 }
 
-// use port and option connect
+// Use port and option connect
 {
   const server = createServer();
   server.listen(0, common.mustCall(() => {
@@ -103,7 +103,7 @@ function createServer() {
   }));
 }
 
-// options is null
+// `options` is null
 {
   const server = createServer();
   server.listen(0, common.mustCall(() => {
@@ -118,7 +118,7 @@ function createServer() {
   }));
 }
 
-// options is undefined
+// `options` is undefined
 {
   const server = createServer();
   server.listen(0, common.mustCall(() => {
diff --git a/test/parallel/test-https-agent-getname.js b/test/parallel/test-https-agent-getname.js
index 5c95da549b20b5..dabb08f074af9a 100644
--- a/test/parallel/test-https-agent-getname.js
+++ b/test/parallel/test-https-agent-getname.js
@@ -15,7 +15,7 @@ assert.strictEqual(
   'localhost:::::::::::::::::::'
 );
 
-// pass all options arguments
+// Pass all options arguments
 const options = {
   host: '0.0.0.0',
   port: 443,
diff --git a/test/parallel/test-https-argument-of-creating.js b/test/parallel/test-https-argument-of-creating.js
index c46dd204c51922..6f1564826eaf74 100644
--- a/test/parallel/test-https-argument-of-creating.js
+++ b/test/parallel/test-https-argument-of-creating.js
@@ -10,7 +10,7 @@ const tls = require('tls');
 
 const dftProtocol = {};
 
-// test for immutable `opts`
+// Test for immutable `opts`
 {
   const opts = { foo: 'bar', ALPNProtocols: [ 'http/1.1' ] };
   const server = https.createServer(opts);
diff --git a/test/parallel/test-https-client-override-global-agent.js b/test/parallel/test-https-client-override-global-agent.js
index 0aaab0d7b3ef96..a4bb2732756b2b 100644
--- a/test/parallel/test-https-client-override-global-agent.js
+++ b/test/parallel/test-https-client-override-global-agent.js
@@ -25,7 +25,7 @@ server.listen(0, common.mustCall(() => {
   https.globalAgent = agent;
 
   makeRequest();
-  assert(agent.sockets.hasOwnProperty(name)); // agent has indeed been used
+  assert(agent.sockets.hasOwnProperty(name)); // Agent has indeed been used
 }));
 
 function makeRequest() {
diff --git a/test/parallel/test-https-client-renegotiation-limit.js b/test/parallel/test-https-client-renegotiation-limit.js
index 3527c48f4b9580..4d3dda3d759e38 100644
--- a/test/parallel/test-https-client-renegotiation-limit.js
+++ b/test/parallel/test-https-client-renegotiation-limit.js
@@ -35,7 +35,7 @@ const fixtures = require('../common/fixtures');
 // Renegotiation as a protocol feature was dropped after TLS1.2.
 tls.DEFAULT_MAX_VERSION = 'TLSv1.2';
 
-// renegotiation limits to test
+// Renegotiation limits to test
 const LIMITS = [0, 1, 2, 3, 5, 10, 16];
 
 {
@@ -96,7 +96,7 @@ function test(next) {
 
       spam();
 
-      // simulate renegotiation attack
+      // Simulate renegotiation attack
       function spam() {
         client.renegotiate({}, (err) => {
           assert.ifError(err);
diff --git a/test/parallel/test-https-strict.js b/test/parallel/test-https-strict.js
index f849ae800fc016..a72168289d54bb 100644
--- a/test/parallel/test-https-strict.js
+++ b/test/parallel/test-https-strict.js
@@ -161,7 +161,7 @@ function makeReq(path, port, error, host, ca) {
 }
 
 function allListening() {
-  // ok, ready to start the tests!
+  // Ok, ready to start the tests!
   const port1 = server1.address().port;
   const port2 = server2.address().port;
   const port3 = server3.address().port;
diff --git a/test/parallel/test-https-timeout.js b/test/parallel/test-https-timeout.js
index e034adc39d2899..9ba621e436859e 100644
--- a/test/parallel/test-https-timeout.js
+++ b/test/parallel/test-https-timeout.js
@@ -33,7 +33,7 @@ const options = {
   cert: fixtures.readKey('agent1-cert.pem')
 };
 
-// a server that never replies
+// A server that never replies
 const server = https.createServer(options, function() {
   console.log('Got request.  Doing nothing.');
 }).listen(0, common.mustCall(function() {
diff --git a/test/parallel/test-icu-punycode.js b/test/parallel/test-icu-punycode.js
index 35dab6232f34bc..7e8dcf37595123 100644
--- a/test/parallel/test-icu-punycode.js
+++ b/test/parallel/test-icu-punycode.js
@@ -9,7 +9,7 @@ const { internalBinding } = require('internal/test/binding');
 const icu = internalBinding('icu');
 const assert = require('assert');
 
-// test hasConverter method
+// Test hasConverter method
 assert(icu.hasConverter('utf-8'),
        'hasConverter should report coverter exists for utf-8');
 assert(!icu.hasConverter('x'),
diff --git a/test/parallel/test-intl.js b/test/parallel/test-intl.js
index 255bf066aa0ff8..7e248bea1dd2a9 100644
--- a/test/parallel/test-intl.js
+++ b/test/parallel/test-intl.js
@@ -115,14 +115,14 @@ if (!common.hasIntl) {
   const collOpts = { sensitivity: 'base', ignorePunctuation: true };
   const coll = new Intl.Collator(['en'], collOpts);
 
-  // ignore punctuation
+  // Ignore punctuation
   assert.strictEqual(coll.compare('blackbird', 'black-bird'), 0);
-  // compare less
+  // Compare less
   assert.strictEqual(coll.compare('blackbird', 'red-bird'), -1);
-  // compare greater
+  // Compare greater
   assert.strictEqual(coll.compare('bluebird', 'blackbird'), 1);
-  // ignore case
+  // Ignore case
   assert.strictEqual(coll.compare('Bluebird', 'bluebird'), 0);
-  // ffi ligature (contraction)
+  // `ffi` ligature (contraction)
   assert.strictEqual(coll.compare('\ufb03', 'ffi'), 0);
 }
diff --git a/test/parallel/test-listen-fd-cluster.js b/test/parallel/test-listen-fd-cluster.js
index 416adb39357ae1..45bb03ce588ae0 100644
--- a/test/parallel/test-listen-fd-cluster.js
+++ b/test/parallel/test-listen-fd-cluster.js
@@ -136,7 +136,7 @@ function master() {
 
 function worker() {
   console.error('worker, about to create server and listen on fd=3');
-  // start a server on fd=3
+  // Start a server on fd=3
   http.createServer(function(req, res) {
     console.error('request on worker');
     console.error('%s %s', req.method, req.url, req.headers);
diff --git a/test/parallel/test-listen-fd-detached-inherit.js b/test/parallel/test-listen-fd-detached-inherit.js
index 9f672a9a557485..81c07d1263e964 100644
--- a/test/parallel/test-listen-fd-detached-inherit.js
+++ b/test/parallel/test-listen-fd-detached-inherit.js
@@ -105,7 +105,7 @@ function parent() {
 
 // Run as a child of the parent() mode.
 function child() {
-  // start a server on fd=3
+  // Start a server on fd=3
   http.createServer(function(req, res) {
     console.error('request on child');
     console.error('%s %s', req.method, req.url, req.headers);
diff --git a/test/parallel/test-listen-fd-detached.js b/test/parallel/test-listen-fd-detached.js
index d2fa7707193168..efa08323047358 100644
--- a/test/parallel/test-listen-fd-detached.js
+++ b/test/parallel/test-listen-fd-detached.js
@@ -102,7 +102,7 @@ function parent() {
 }
 
 function child() {
-  // start a server on fd=3
+  // Start a server on fd=3
   http.createServer(function(req, res) {
     console.error('request on child');
     console.error('%s %s', req.method, req.url, req.headers);
diff --git a/test/parallel/test-listen-fd-server.js b/test/parallel/test-listen-fd-server.js
index a09a01f219daf1..3b6a0a0fac7abd 100644
--- a/test/parallel/test-listen-fd-server.js
+++ b/test/parallel/test-listen-fd-server.js
@@ -74,7 +74,7 @@ function child() {
     process.exit(0);
   });
 
-  // start a server on fd=3
+  // Start a server on fd=3
   http.createServer(function(req, res) {
     console.error('request on child');
     console.error('%s %s', req.method, req.url, req.headers);
diff --git a/test/parallel/test-microtask-queue-run-immediate.js b/test/parallel/test-microtask-queue-run-immediate.js
index 2d4e21f83aa6ef..577391993bcc65 100644
--- a/test/parallel/test-microtask-queue-run-immediate.js
+++ b/test/parallel/test-microtask-queue-run-immediate.js
@@ -33,7 +33,7 @@ process.on('exit', function() {
   assert.strictEqual(done, 2);
 });
 
-// no nextTick, microtask
+// No nextTick, microtask
 setImmediate(function() {
   enqueueMicrotask(function() {
     done++;
diff --git a/test/parallel/test-microtask-queue-run.js b/test/parallel/test-microtask-queue-run.js
index 7a1667819f6758..5281cb4f3c2ed2 100644
--- a/test/parallel/test-microtask-queue-run.js
+++ b/test/parallel/test-microtask-queue-run.js
@@ -33,7 +33,7 @@ process.on('exit', function() {
   assert.strictEqual(done, 2);
 });
 
-// no nextTick, microtask
+// No nextTick, microtask
 setTimeout(function() {
   enqueueMicrotask(function() {
     done++;
diff --git a/test/parallel/test-net-can-reset-timeout.js b/test/parallel/test-net-can-reset-timeout.js
index 69f6c9288b77f7..2fac07eab05e23 100644
--- a/test/parallel/test-net-can-reset-timeout.js
+++ b/test/parallel/test-net-can-reset-timeout.js
@@ -33,7 +33,7 @@ const server = net.createServer(common.mustCall(function(stream) {
 
   stream.once('timeout', common.mustCall(function() {
     console.log('timeout');
-    // try to reset the timeout.
+    // Try to reset the timeout.
     stream.write('WHAT.');
   }));
 
diff --git a/test/parallel/test-net-connect-memleak.js b/test/parallel/test-net-connect-memleak.js
index 4efceee0eae138..2f06e56e1f631e 100644
--- a/test/parallel/test-net-connect-memleak.js
+++ b/test/parallel/test-net-connect-memleak.js
@@ -42,7 +42,7 @@ const gcListener = { ongc() { collected = true; } };
   const sock = net.createConnection(
     server.address().port,
     common.mustCall(() => {
-      assert.strictEqual(gcObject, gcObject); // keep reference alive
+      assert.strictEqual(gcObject, gcObject); // Keep reference alive
       assert.strictEqual(collected, false);
       setImmediate(done, sock);
     }));
diff --git a/test/parallel/test-net-pingpong.js b/test/parallel/test-net-pingpong.js
index 4ab36fc23957b5..99a02eda22fb1d 100644
--- a/test/parallel/test-net-pingpong.js
+++ b/test/parallel/test-net-pingpong.js
@@ -67,7 +67,7 @@ function pingPongTest(port, host) {
 
     socket.on('end', common.mustCall(function() {
       assert.strictEqual(socket.allowHalfOpen, true);
-      assert.strictEqual(socket.writable, true); // because allowHalfOpen
+      assert.strictEqual(socket.writable, true); // Because allowHalfOpen
       assert.strictEqual(socket.readable, false);
       socket.end();
     }));
diff --git a/test/parallel/test-net-server-listen-handle.js b/test/parallel/test-net-server-listen-handle.js
index 0d59bd76cad8a8..58f9d2ae3775b7 100644
--- a/test/parallel/test-net-server-listen-handle.js
+++ b/test/parallel/test-net-server-listen-handle.js
@@ -53,7 +53,7 @@ function randomHandle(type) {
     assert.fail(`unable to bind ${handleName}: ${getSystemErrorName(errno)}`);
   }
 
-  if (!common.isWindows) {  // fd doesn't work on windows
+  if (!common.isWindows) {  // `fd` doesn't work on Windows.
     // err >= 0 but fd = -1, should not happen
     assert.notStrictEqual(handle.fd, -1,
                           `Bound ${handleName} has fd -1 and errno ${errno}`);
@@ -82,7 +82,7 @@ function randomPipes(number) {
 
 // Not a public API, used by child_process
 if (!common.isWindows) {  // Windows doesn't support {fd: <n>}
-  const handles = randomPipes(2);  // generate pipes in advance
+  const handles = randomPipes(2);  // Generate pipes in advance
   // Test listen(pipe)
   net.createServer()
     .listen(handles[0])
@@ -120,7 +120,7 @@ if (!common.isWindows) {  // Windows doesn't support {fd: <n>}
 }
 
 if (!common.isWindows) {  // Windows doesn't support {fd: <n>}
-  const handles = randomPipes(6);  // generate pipes in advance
+  const handles = randomPipes(6);  // Generate pipes in advance
   // Test listen({handle: pipe}, cb)
   net.createServer()
     .listen({ handle: handles[0] }, closePipeServer(handles[0]));
diff --git a/test/parallel/test-net-server-unref-persistent.js b/test/parallel/test-net-server-unref-persistent.js
index 9b9460635df3ca..b772782100f3b9 100644
--- a/test/parallel/test-net-server-unref-persistent.js
+++ b/test/parallel/test-net-server-unref-persistent.js
@@ -3,7 +3,7 @@ const common = require('../common');
 const net = require('net');
 const server = net.createServer();
 
-// unref before listening
+// Unref before listening
 server.unref();
 server.listen();
 
diff --git a/test/parallel/test-net-socket-local-address.js b/test/parallel/test-net-socket-local-address.js
index dda2d5acadb751..58645322f45100 100644
--- a/test/parallel/test-net-socket-local-address.js
+++ b/test/parallel/test-net-socket-local-address.js
@@ -1,6 +1,6 @@
 'use strict';
 const common = require('../common');
-// skip test in FreeBSD jails
+// Skip test in FreeBSD jails
 if (common.inFreeBSDJail)
   common.skip('In a FreeBSD jail');
 
diff --git a/test/parallel/test-path-relative.js b/test/parallel/test-path-relative.js
index 5d5d118cc6f45c..599381cdccfcb9 100644
--- a/test/parallel/test-path-relative.js
+++ b/test/parallel/test-path-relative.js
@@ -35,7 +35,7 @@ const relativeTests = [
     ]
   ],
   [ path.posix.relative,
-    // arguments          result
+    // Arguments          result
     [['/var/lib', '/var', '..'],
      ['/var/lib', '/bin', '../../bin'],
      ['/var/lib', '/var/lib', ''],
diff --git a/test/parallel/test-process-kill-pid.js b/test/parallel/test-process-kill-pid.js
index 698fa4cf6268ea..6d0af8bd3ef91a 100644
--- a/test/parallel/test-process-kill-pid.js
+++ b/test/parallel/test-process-kill-pid.js
@@ -23,7 +23,7 @@
 const common = require('../common');
 const assert = require('assert');
 
-// test variants of pid
+// Test variants of pid
 //
 // null: TypeError
 // undefined: TypeError
diff --git a/test/parallel/test-process-raw-debug.js b/test/parallel/test-process-raw-debug.js
index 090525e18c5d3e..ba5ae74f0ff720 100644
--- a/test/parallel/test-process-raw-debug.js
+++ b/test/parallel/test-process-raw-debug.js
@@ -58,7 +58,7 @@ function parent() {
 }
 
 function child() {
-  // even when all hope is lost...
+  // Even when all hope is lost...
 
   process.nextTick = function() {
     throw new Error('No ticking!');
diff --git a/test/parallel/test-promises-unhandled-proxy-rejections.js b/test/parallel/test-promises-unhandled-proxy-rejections.js
index b3cf5719cb9ab0..659db4d17911ee 100644
--- a/test/parallel/test-promises-unhandled-proxy-rejections.js
+++ b/test/parallel/test-promises-unhandled-proxy-rejections.js
@@ -39,5 +39,5 @@ common.expectWarning({
   UnhandledPromiseRejectionWarning: expectedPromiseWarning,
 });
 
-// ensure this doesn't crash
+// Ensure this doesn't crash
 Promise.reject(thorny);
diff --git a/test/parallel/test-promises-unhandled-symbol-rejections.js b/test/parallel/test-promises-unhandled-symbol-rejections.js
index d777a13e62e984..460acaca57c6d4 100644
--- a/test/parallel/test-promises-unhandled-symbol-rejections.js
+++ b/test/parallel/test-promises-unhandled-symbol-rejections.js
@@ -23,5 +23,5 @@ common.expectWarning({
   ],
 });
 
-// ensure this doesn't crash
+// Ensure this doesn't crash
 Promise.reject(Symbol());
diff --git a/test/parallel/test-querystring-escape.js b/test/parallel/test-querystring-escape.js
index 25a800a09a684c..fedc09812400fd 100644
--- a/test/parallel/test-querystring-escape.js
+++ b/test/parallel/test-querystring-escape.js
@@ -22,7 +22,7 @@ common.expectsError(
   }
 );
 
-// using toString for objects
+// Using toString for objects
 assert.strictEqual(
   qs.escape({ test: 5, toString: () => 'test', valueOf: () => 10 }),
   'test'
diff --git a/test/parallel/test-querystring.js b/test/parallel/test-querystring.js
index b26f41a4663c8b..de1768103d94cd 100644
--- a/test/parallel/test-querystring.js
+++ b/test/parallel/test-querystring.js
@@ -223,7 +223,7 @@ qsNoMungeTestCases.forEach((testCase) => {
   assert.deepStrictEqual(qs.stringify(testCase[1], '&', '='), testCase[0]);
 });
 
-// test the nested qs-in-qs case
+// Test the nested qs-in-qs case
 {
   const f = qs.parse('a=b&q=x%3Dy%26y%3Dz');
   check(f, createWithNoPrototype([
@@ -254,7 +254,7 @@ qsNoMungeTestCases.forEach((testCase) => {
   check(f.q, expectedInternal);
 }
 
-// now test stringifying
+// Now test stringifying
 
 // basic
 qsTestCases.forEach((testCase) => {
@@ -279,7 +279,7 @@ common.expectsError(
   }
 );
 
-// coerce numbers to string
+// Coerce numbers to string
 assert.strictEqual(qs.stringify({ foo: 0 }), 'foo=0');
 assert.strictEqual(qs.stringify({ foo: -0 }), 'foo=0');
 assert.strictEqual(qs.stringify({ foo: 3 }), 'foo=3');
@@ -434,7 +434,7 @@ qsUnescapeTestCases.forEach((testCase) => {
   assert.strictEqual(qs.unescapeBuffer(testCase[0]).toString(), testCase[1]);
 });
 
-// test overriding .unescape
+// Test overriding .unescape
 {
   const prevUnescape = qs.unescape;
   qs.unescape = (str) => {
diff --git a/test/parallel/test-readline-interface.js b/test/parallel/test-readline-interface.js
index fba215e225b03d..5096198a71d9eb 100644
--- a/test/parallel/test-readline-interface.js
+++ b/test/parallel/test-readline-interface.js
@@ -73,7 +73,7 @@ function isWarned(emitter) {
 }
 
 {
-  // set crlfDelay to 5000ms
+  // Set crlfDelay to 5000ms
   const fi = new FakeInput();
   const rli = new readline.Interface({
     input: fi,
@@ -98,7 +98,7 @@ function isWarned(emitter) {
     rli.close();
   }
 
-  // default history size 30
+  // Default history size 30
   {
     const fi = new FakeInput();
     const rli = new readline.Interface(
@@ -126,7 +126,7 @@ function isWarned(emitter) {
     assert.ok(called);
   }
 
-  // sending a blank line
+  // Sending a blank line
   {
     const fi = new FakeInput();
     const rli = new readline.Interface(
@@ -531,7 +531,7 @@ function isWarned(emitter) {
     rli.close();
   }
 
-  // calling the question callback
+  // Calling the question callback
   {
     let called = false;
     const fi = new FakeInput();
@@ -576,7 +576,7 @@ function isWarned(emitter) {
       rli.close();
     }
 
-    // sending a multi-line question
+    // Sending a multi-line question
     {
       const fi = new FakeInput();
       const rli = new readline.Interface(
diff --git a/test/parallel/test-readline-keys.js b/test/parallel/test-readline-keys.js
index f61c64043fecc1..0f5ca4d71443fd 100644
--- a/test/parallel/test-readline-keys.js
+++ b/test/parallel/test-readline-keys.js
@@ -82,7 +82,7 @@ const addKeyIntervalTest = (sequences, expectedKeys, interval = 550,
   return fn;
 };
 
-// regular alphanumerics
+// Regular alphanumerics
 addTest('io.JS', [
   { name: 'i', sequence: 'i' },
   { name: 'o', sequence: 'o' },
@@ -91,14 +91,14 @@ addTest('io.JS', [
   { name: 's', sequence: 'S', shift: true },
 ]);
 
-// named characters
+// Named characters
 addTest('\n\r\t', [
   { name: 'enter', sequence: '\n' },
   { name: 'return', sequence: '\r' },
   { name: 'tab', sequence: '\t' },
 ]);
 
-// space and backspace
+// Space and backspace
 addTest('\b\x7f\x1b\b\x1b\x7f\x1b\x1b  \x1b ', [
   { name: 'backspace', sequence: '\b' },
   { name: 'backspace', sequence: '\x7f' },
@@ -109,19 +109,19 @@ addTest('\b\x7f\x1b\b\x1b\x7f\x1b\x1b  \x1b ', [
   { name: 'space', sequence: '\x1b ', meta: true },
 ]);
 
-// escape key
+// Escape key
 addTest('\x1b\x1b\x1b', [
   { name: 'escape', sequence: '\x1b\x1b\x1b', meta: true },
 ]);
 
-// control keys
+// Control keys
 addTest('\x01\x0b\x10', [
   { name: 'a', sequence: '\x01', ctrl: true },
   { name: 'k', sequence: '\x0b', ctrl: true },
   { name: 'p', sequence: '\x10', ctrl: true },
 ]);
 
-// alt keys
+// Alt keys
 addTest('a\x1baA\x1bA', [
   { name: 'a', sequence: 'a' },
   { name: 'a', sequence: '\x1ba', meta: true },
@@ -145,7 +145,7 @@ addTest('\x1b[11~\x1b[12~\x1b[13~\x1b[14~', [
   { name: 'f4', sequence: '\x1b[14~', code: '[14~' },
 ]);
 
-// from Cygwin and used in libuv
+// From Cygwin and used in libuv
 addTest('\x1b[[A\x1b[[B\x1b[[C\x1b[[D\x1b[[E', [
   { name: 'f1', sequence: '\x1b[[A', code: '[[A' },
   { name: 'f2', sequence: '\x1b[[B', code: '[[B' },
@@ -154,7 +154,7 @@ addTest('\x1b[[A\x1b[[B\x1b[[C\x1b[[D\x1b[[E', [
   { name: 'f5', sequence: '\x1b[[E', code: '[[E' },
 ]);
 
-// common
+// Common
 addTest('\x1b[15~\x1b[17~\x1b[18~\x1b[19~\x1b[20~\x1b[21~\x1b[23~\x1b[24~', [
   { name: 'f5', sequence: '\x1b[15~', code: '[15~' },
   { name: 'f6', sequence: '\x1b[17~', code: '[17~' },
@@ -188,7 +188,7 @@ addTest('\x1bOA\x1bOB\x1bOC\x1bOD\x1bOE\x1bOF\x1bOH', [
   { name: 'home', sequence: '\x1bOH', code: 'OH' },
 ]);
 
-// old xterm shift-arrows
+// Old xterm shift-arrows
 addTest('\x1bO2A\x1bO2B', [
   { name: 'up', sequence: '\x1bO2A', code: 'OA', shift: true },
   { name: 'down', sequence: '\x1bO2B', code: 'OB', shift: true },
@@ -224,7 +224,7 @@ addTest('\x1b[A\x1b[B\x1b[2A\x1b[2B', [
   { name: 'down', sequence: '\x1b[2B', code: '[B', shift: true },
 ]);
 
-// rxvt keys with modifiers
+// `rxvt` keys with modifiers.
 // eslint-disable-next-line max-len
 addTest('\x1b[20~\x1b[2$\x1b[2^\x1b[3$\x1b[3^\x1b[5$\x1b[5^\x1b[6$\x1b[6^\x1b[7$\x1b[7^\x1b[8$\x1b[8^', [
   { name: 'f9', sequence: '\x1b[20~', code: '[20~' },
@@ -242,7 +242,7 @@ addTest('\x1b[20~\x1b[2$\x1b[2^\x1b[3$\x1b[3^\x1b[5$\x1b[5^\x1b[6$\x1b[6^\x1b[7$
   { name: 'end', sequence: '\x1b[8^', code: '[8^', ctrl: true },
 ]);
 
-// misc
+// Misc
 addTest('\x1b[Z', [
   { name: 'tab', sequence: '\x1b[Z', code: '[Z', shift: true },
 ]);
@@ -277,7 +277,7 @@ addTest('\x1b[DD\x1b[2DD\x1b[2^D', [
   { name: 'd', sequence: 'D', shift: true },
 ]);
 
-// color sequences
+// Color sequences
 addTest('\x1b[31ma\x1b[39ma', [
   { name: 'undefined', sequence: '\x1b[31m', code: '[31m' },
   { name: 'a', sequence: 'a' },
@@ -285,7 +285,7 @@ addTest('\x1b[31ma\x1b[39ma', [
   { name: 'a', sequence: 'a' },
 ]);
 
-// rxvt keys with modifiers
+// `rxvt` keys with modifiers.
 addTest('\x1b[a\x1b[b\x1b[c\x1b[d\x1b[e', [
   { name: 'up', sequence: '\x1b[a', code: '[a', shift: true },
   { name: 'down', sequence: '\x1b[b', code: '[b', shift: true },
@@ -303,13 +303,13 @@ addTest('\x1bOa\x1bOb\x1bOc\x1bOd\x1bOe', [
 ]);
 
 // Reduce array of addKeyIntervalTest(..) right to left
-// with () => {} as initial function
+// with () => {} as initial function.
 const runKeyIntervalTests = [
-  // escape character
+  // Escape character
   addKeyIntervalTest('\x1b', [
     { name: 'escape', sequence: '\x1b', meta: true }
   ]),
-  // chain of escape characters
+  // Chain of escape characters.
   addKeyIntervalTest('\x1b\x1b\x1b\x1b'.split(''), [
     { name: 'escape', sequence: '\x1b', meta: true },
     { name: 'escape', sequence: '\x1b', meta: true },
@@ -318,5 +318,5 @@ const runKeyIntervalTests = [
   ])
 ].reverse().reduce((acc, fn) => fn(acc), () => {});
 
-// Run key interval tests one after another
+// Run key interval tests one after another.
 runKeyIntervalTests();
diff --git a/test/parallel/test-repl-autolibs.js b/test/parallel/test-repl-autolibs.js
index 976cad84361d03..5cf3b1497221d0 100644
--- a/test/parallel/test-repl-autolibs.js
+++ b/test/parallel/test-repl-autolibs.js
@@ -55,7 +55,7 @@ function test2() {
   putIn.write = function(data) {
     gotWrite = true;
     if (data.length) {
-      // repl response error message
+      // REPL response error message
       assert.strictEqual(data, '{}\n');
       // Original value wasn't overwritten
       assert.strictEqual(val, global.url);
diff --git a/test/parallel/test-repl-context.js b/test/parallel/test-repl-context.js
index 001e2ffd4e1ede..287d8adc295d7a 100644
--- a/test/parallel/test-repl-context.js
+++ b/test/parallel/test-repl-context.js
@@ -58,7 +58,7 @@ const stream = new ArrayStream();
   assert.strictEqual(server.lines[0], '_ = 500;');
   assert.strictEqual(server.last, 500);
 
-  // reset the server context
+  // Reset the server context
   server.resetContext();
   assert.ok(!server.underscoreAssigned);
   assert.strictEqual(server.lines.length, 0);
diff --git a/test/parallel/test-repl-end-emits-exit.js b/test/parallel/test-repl-end-emits-exit.js
index 8de0a006dfc49b..4e1f3d84f5e056 100644
--- a/test/parallel/test-repl-end-emits-exit.js
+++ b/test/parallel/test-repl-end-emits-exit.js
@@ -38,7 +38,7 @@ function testTerminalMode() {
   });
 
   process.nextTick(function() {
-    // manually fire a ^D keypress
+    // Manually fire a ^D keypress
     stream.emit('data', '\u0004');
   });
 
diff --git a/test/parallel/test-repl-options.js b/test/parallel/test-repl-options.js
index f6f6273f374034..cbb5a9a6e580ec 100644
--- a/test/parallel/test-repl-options.js
+++ b/test/parallel/test-repl-options.js
@@ -52,7 +52,7 @@ assert.strictEqual(r1.ignoreUndefined, false);
 assert.strictEqual(r1.replMode, repl.REPL_MODE_SLOPPY);
 assert.strictEqual(r1.historySize, 30);
 
-// test r1 for backwards compact
+// Test r1 for backwards compact
 assert.strictEqual(r1.rli.input, stream);
 assert.strictEqual(r1.rli.output, stream);
 assert.strictEqual(r1.rli.input, r1.inputStream);
@@ -87,7 +87,7 @@ assert.strictEqual(r2.writer, writer);
 assert.strictEqual(r2.replMode, repl.REPL_MODE_STRICT);
 assert.strictEqual(r2.historySize, 50);
 
-// test r2 for backwards compact
+// Test r2 for backwards compact
 assert.strictEqual(r2.rli.input, stream);
 assert.strictEqual(r2.rli.output, stream);
 assert.strictEqual(r2.rli.input, r2.inputStream);
diff --git a/test/parallel/test-repl-save-load.js b/test/parallel/test-repl-save-load.js
index 74841d86ff6ec0..d36a2b74d4373a 100644
--- a/test/parallel/test-repl-save-load.js
+++ b/test/parallel/test-repl-save-load.js
@@ -99,7 +99,7 @@ let loadFile = join(tmpdir.path, 'file.does.not.exist');
 putIn.write = function(data) {
   // Make sure I get a failed to load message and not some crazy error
   assert.strictEqual(data, `Failed to load:${loadFile}\n`);
-  // eat me to avoid work
+  // Eat me to avoid work
   putIn.write = () => {};
 };
 putIn.run([`.load ${loadFile}`]);
diff --git a/test/parallel/test-repl-tab-complete.js b/test/parallel/test-repl-tab-complete.js
index 558b6cab47e2ae..02cd06c9534bc5 100644
--- a/test/parallel/test-repl-tab-complete.js
+++ b/test/parallel/test-repl-tab-complete.js
@@ -528,7 +528,7 @@ testCustomCompleterAsyncMode.complete('a', common.mustCall((error, data) => {
   ]);
 }));
 
-// tab completion in editor mode
+// Tab completion in editor mode
 const editorStream = new ArrayStream();
 const editor = repl.start({
   stream: editorStream,
diff --git a/test/parallel/test-repl.js b/test/parallel/test-repl.js
index 1426330e20ad85..ad674cb3ab00f4 100644
--- a/test/parallel/test-repl.js
+++ b/test/parallel/test-repl.js
@@ -35,7 +35,7 @@ const prompt_tcp = 'node via TCP socket> ';
 // Absolute path to test/fixtures/a.js
 const moduleFilename = fixtures.path('a');
 
-// function for REPL to run
+// Function for REPL to run
 global.invoke_me = function(arg) {
   return `invoked ${arg}`;
 };
@@ -358,7 +358,7 @@ const errorTests = [
     send: ')',
     expect: 'undefined'
   },
-  // npm prompt error message
+  // `npm` prompt error message.
   {
     send: 'npm install foobar',
     expect: [
@@ -676,7 +676,7 @@ const errorTests = [
       /^SyntaxError: /
     ]
   },
-  // bring back the repl to prompt
+  // Bring back the repl to prompt
   {
     send: '.break',
     expect: ''
diff --git a/test/parallel/test-require-extension-over-directory.js b/test/parallel/test-require-extension-over-directory.js
index cc896d7b61b090..92258761513919 100644
--- a/test/parallel/test-require-extension-over-directory.js
+++ b/test/parallel/test-require-extension-over-directory.js
@@ -1,5 +1,5 @@
 'use strict';
-// fixes regression from v4
+// Fixes regression from v4
 require('../common');
 const assert = require('assert');
 const fixtures = require('../common/fixtures');
diff --git a/test/parallel/test-require-symlink.js b/test/parallel/test-require-symlink.js
index c73fdcd41e6efa..5c9b0fbdef3595 100644
--- a/test/parallel/test-require-symlink.js
+++ b/test/parallel/test-require-symlink.js
@@ -63,12 +63,12 @@ function test() {
   fs.symlinkSync(linkTarget, linkDir, 'dir');
   fs.symlinkSync(linkScriptTarget, linkScript);
 
-  // load symlinked-module
+  // Load symlinked-module
   const fooModule = require(path.join(tmpDirTarget, 'foo.js'));
   assert.strictEqual(fooModule.dep1.bar.version, 'CORRECT_VERSION');
   assert.strictEqual(fooModule.dep2.bar.version, 'CORRECT_VERSION');
 
-  // load symlinked-script as main
+  // Load symlinked-script as main
   const node = process.execPath;
   const child = spawn(node, ['--preserve-symlinks', linkScript]);
   child.on('close', function(code, signal) {
diff --git a/test/parallel/test-stream-big-push.js b/test/parallel/test-stream-big-push.js
index 5eabd4837e6b7c..f9e75edd3f89d1 100644
--- a/test/parallel/test-stream-big-push.js
+++ b/test/parallel/test-stream-big-push.js
@@ -51,10 +51,10 @@ r._read = common.mustCall(_read, 3);
 
 r.on('end', common.mustCall());
 
-// push some data in to start.
-// we've never gotten any read event at this point.
+// Push some data in to start.
+// We've never gotten any read event at this point.
 const ret = r.push(str);
-// should be false.  > hwm
+// Should be false.  > hwm
 assert(!ret);
 let chunk = r.read();
 assert.strictEqual(chunk, str);
diff --git a/test/parallel/test-stream-finished.js b/test/parallel/test-stream-finished.js
index e06017920c8a30..329b4ed42b0c43 100644
--- a/test/parallel/test-stream-finished.js
+++ b/test/parallel/test-stream-finished.js
@@ -104,7 +104,7 @@ const { promisify } = require('util');
   }));
 
   rs.push(null);
-  rs.emit('close'); // should not trigger an error
+  rs.emit('close'); // Should not trigger an error
   rs.resume();
 }
 
@@ -115,7 +115,7 @@ const { promisify } = require('util');
     assert(err, 'premature close error');
   }));
 
-  rs.emit('close'); // should trigger error
+  rs.emit('close'); // Should trigger error
   rs.push(null);
   rs.resume();
 }
diff --git a/test/parallel/test-stream-readable-destroy.js b/test/parallel/test-stream-readable-destroy.js
index 9f56467e203dd5..05e7dd464ddca0 100644
--- a/test/parallel/test-stream-readable-destroy.js
+++ b/test/parallel/test-stream-readable-destroy.js
@@ -166,7 +166,7 @@ const assert = require('assert');
 }
 
 {
-  // destroy and destroy callback
+  // Destroy and destroy callback
   const read = new Readable({
     read() {}
   });
diff --git a/test/parallel/test-stream-readable-event.js b/test/parallel/test-stream-readable-event.js
index e248bed4b5b3e3..4f2383508aa61c 100644
--- a/test/parallel/test-stream-readable-event.js
+++ b/test/parallel/test-stream-readable-event.js
@@ -118,7 +118,7 @@ const Readable = require('stream').Readable;
   // #20923
   const r = new Readable();
   r._read = function() {
-    // actually doing thing here
+    // Actually doing thing here
   };
   r.on('data', function() {});
 
diff --git a/test/parallel/test-stream-readable-pause-and-resume.js b/test/parallel/test-stream-readable-pause-and-resume.js
index 505327e247da38..3169023d90acaf 100644
--- a/test/parallel/test-stream-readable-pause-and-resume.js
+++ b/test/parallel/test-stream-readable-pause-and-resume.js
@@ -34,7 +34,7 @@ function readAndPause() {
       readAndPause();
       rs.resume();
     });
-  }, 1); // only call ondata once
+  }, 1); // Only call ondata once
 
   rs.on('data', ondata);
 }
diff --git a/test/parallel/test-stream-readable-reading-readingMore.js b/test/parallel/test-stream-readable-reading-readingMore.js
index e57a808286619d..f616b460488e75 100644
--- a/test/parallel/test-stream-readable-reading-readingMore.js
+++ b/test/parallel/test-stream-readable-reading-readingMore.js
@@ -40,10 +40,10 @@ const Readable = require('stream').Readable;
     // If the stream has ended, we shouldn't be reading
     assert.strictEqual(state.ended, !state.reading);
 
-    // consume all the data
+    // Consume all the data
     while (readable.read() !== null) {}
 
-    if (expectedReadingMore.length === 0) // reached end of stream
+    if (expectedReadingMore.length === 0) // Reached end of stream
       process.nextTick(common.mustCall(onStreamEnd, 1));
   }, 3));
 
@@ -94,7 +94,7 @@ const Readable = require('stream').Readable;
   readable.on('end', common.mustCall(onStreamEnd));
   readable.push('pushed');
 
-  // stop emitting 'data' events
+  // Stop emitting 'data' events
   assert.strictEqual(state.flowing, true);
   readable.pause();
 
@@ -152,7 +152,7 @@ const Readable = require('stream').Readable;
   process.nextTick(function() {
     readable.resume();
 
-    // stop emitting 'data' events
+    // Stop emitting 'data' events
     assert.strictEqual(state.flowing, true);
     readable.pause();
 
diff --git a/test/parallel/test-stream-transform-split-highwatermark.js b/test/parallel/test-stream-transform-split-highwatermark.js
index 7837b009cd6a0e..bcc33d26a6f665 100644
--- a/test/parallel/test-stream-transform-split-highwatermark.js
+++ b/test/parallel/test-stream-transform-split-highwatermark.js
@@ -12,7 +12,7 @@ function testTransform(expectedReadableHwm, expectedWritableHwm, options) {
   assert.strictEqual(t._writableState.highWaterMark, expectedWritableHwm);
 }
 
-// test overriding defaultHwm
+// Test overriding defaultHwm
 testTransform(666, DEFAULT, { readableHighWaterMark: 666 });
 testTransform(DEFAULT, 777, { writableHighWaterMark: 777 });
 testTransform(666, 777, {
@@ -24,7 +24,7 @@ testTransform(666, 777, {
 testTransform(0, DEFAULT, { readableHighWaterMark: 0 });
 testTransform(DEFAULT, 0, { writableHighWaterMark: 0 });
 
-// test highWaterMark overriding
+// Test highWaterMark overriding
 testTransform(555, 555, {
   highWaterMark: 555,
   readableHighWaterMark: 666,
@@ -54,7 +54,7 @@ testTransform(0, 0, {
   writableHighWaterMark: 777,
 });
 
-// test undefined, null
+// Test undefined, null
 [undefined, null].forEach((v) => {
   testTransform(DEFAULT, DEFAULT, { readableHighWaterMark: v });
   testTransform(DEFAULT, DEFAULT, { writableHighWaterMark: v });
diff --git a/test/parallel/test-stream-unshift-read-race.js b/test/parallel/test-stream-unshift-read-race.js
index 69f966e05f4f36..f7b633338cb810 100644
--- a/test/parallel/test-stream-unshift-read-race.js
+++ b/test/parallel/test-stream-unshift-read-race.js
@@ -46,7 +46,7 @@ let pushedNull = false;
 r._read = function(n) {
   assert(!pushedNull, '_read after null push');
 
-  // every third chunk is fast
+  // Every third chunk is fast
   push(!(chunks % 3));
 
   function push(fast) {
diff --git a/test/parallel/test-stream-writable-destroy.js b/test/parallel/test-stream-writable-destroy.js
index 56e17990794a79..a431d6d48d1c8e 100644
--- a/test/parallel/test-stream-writable-destroy.js
+++ b/test/parallel/test-stream-writable-destroy.js
@@ -205,7 +205,7 @@ const assert = require('assert');
 }
 
 {
-  // destroy and destroy callback
+  // Destroy and destroy callback
   const write = new Writable({
     write(chunk, enc, cb) { cb(); }
   });
diff --git a/test/parallel/test-stream-writableState-ending.js b/test/parallel/test-stream-writableState-ending.js
index 69afd1af5343dc..d301d355cc1417 100644
--- a/test/parallel/test-stream-writableState-ending.js
+++ b/test/parallel/test-stream-writableState-ending.js
@@ -32,6 +32,6 @@ const result = writable.end('testing function end()', () => {
 // End returns the writable instance
 assert.strictEqual(result, writable);
 
-// ending, ended = true.
+// Ending, ended = true.
 // finished = false.
 testStates(true, false, true);
diff --git a/test/parallel/test-stream-writableState-uncorked-bufferedRequestCount.js b/test/parallel/test-stream-writableState-uncorked-bufferedRequestCount.js
index 0cf9179ac49847..b7375b9fa2bae0 100644
--- a/test/parallel/test-stream-writableState-uncorked-bufferedRequestCount.js
+++ b/test/parallel/test-stream-writableState-uncorked-bufferedRequestCount.js
@@ -24,11 +24,11 @@ assert.strictEqual(writable._writableState.bufferedRequestCount, 0);
 writable.cork();
 assert.strictEqual(writable._writableState.corked, 2);
 
-// the first chunk is buffered
+// The first chunk is buffered
 writable.write('first chunk');
 assert.strictEqual(writable._writableState.bufferedRequestCount, 1);
 
-// first uncork does nothing
+// First uncork does nothing
 writable.uncork();
 assert.strictEqual(writable._writableState.corked, 1);
 assert.strictEqual(writable._writableState.bufferedRequestCount, 1);
diff --git a/test/parallel/test-stream2-push.js b/test/parallel/test-stream2-push.js
index 9d209c18b9f489..748a77b9c496ba 100644
--- a/test/parallel/test-stream2-push.js
+++ b/test/parallel/test-stream2-push.js
@@ -97,7 +97,7 @@ writer._write = function(chunk, encoding, cb) {
 writer.on('finish', finish);
 
 
-// now emit some chunks.
+// Now emit some chunks.
 
 const chunk = 'asdfg';
 
diff --git a/test/parallel/test-stream2-readable-from-list.js b/test/parallel/test-stream2-readable-from-list.js
index 0210a1848df03a..0ab7c059d66a85 100644
--- a/test/parallel/test-stream2-readable-from-list.js
+++ b/test/parallel/test-stream2-readable-from-list.js
@@ -64,7 +64,7 @@ function bufferListFromArray(arr) {
   ret = fromList(2, { buffer: list, length: 8 });
   assert.strictEqual(ret.toString(), 'ba');
 
-  // read more than we have.
+  // Read more than we have.
   ret = fromList(100, { buffer: list, length: 6 });
   assert.strictEqual(ret.toString(), 'zykuel');
 
@@ -92,7 +92,7 @@ function bufferListFromArray(arr) {
   ret = fromList(2, { buffer: list, length: 8, decoder: true });
   assert.strictEqual(ret, 'ba');
 
-  // read more than we have.
+  // Read more than we have.
   ret = fromList(100, { buffer: list, length: 6, decoder: true });
   assert.strictEqual(ret, 'zykuel');
 
diff --git a/test/parallel/test-stream2-readable-non-empty-end.js b/test/parallel/test-stream2-readable-non-empty-end.js
index 3c0b5eb4085e2e..ba289fb91275e3 100644
--- a/test/parallel/test-stream2-readable-non-empty-end.js
+++ b/test/parallel/test-stream2-readable-non-empty-end.js
@@ -59,11 +59,11 @@ test.on('readable', function() {
 test.read(0);
 
 function next() {
-  // now let's make 'end' happen
+  // Now let's make 'end' happen
   test.removeListener('end', thrower);
   test.on('end', common.mustCall());
 
-  // one to get the last byte
+  // One to get the last byte
   let r = test.read();
   assert(r);
   assert.strictEqual(r.length, 1);
diff --git a/test/parallel/test-stream2-transform.js b/test/parallel/test-stream2-transform.js
index b27b4116f3c84e..fa24ce152d71ed 100644
--- a/test/parallel/test-stream2-transform.js
+++ b/test/parallel/test-stream2-transform.js
@@ -178,7 +178,7 @@ const Transform = require('_stream_transform');
   // Verify asymmetric transform (expand)
   const pt = new Transform();
 
-  // emit each chunk 2 times.
+  // Emit each chunk 2 times.
   pt._transform = function(chunk, encoding, cb) {
     setTimeout(function() {
       pt.push(chunk);
@@ -229,7 +229,7 @@ const Transform = require('_stream_transform');
   };
 
   pt._flush = function(cb) {
-    // just output whatever we have.
+    // Just output whatever we have.
     pt.push(Buffer.from(this.state));
     this.state = '';
     cb();
diff --git a/test/parallel/test-stream2-writable.js b/test/parallel/test-stream2-writable.js
index af38df7e684aac..5b25da0b67c0b8 100644
--- a/test/parallel/test-stream2-writable.js
+++ b/test/parallel/test-stream2-writable.js
@@ -55,7 +55,7 @@ for (let i = 0; i < chunks.length; i++) {
   });
 
   tw.on('finish', common.mustCall(function() {
-    // got chunks in the right order
+    // Got chunks in the right order
     assert.deepStrictEqual(tw.buffer, chunks);
   }));
 
@@ -96,7 +96,7 @@ for (let i = 0; i < chunks.length; i++) {
   let drains = 0;
 
   tw.on('finish', common.mustCall(function() {
-    // got chunks in the right order
+    // Got chunks in the right order
     assert.deepStrictEqual(tw.buffer, chunks);
     assert.strictEqual(drains, 17);
   }));
@@ -142,7 +142,7 @@ for (let i = 0; i < chunks.length; i++) {
       undefined ];
 
   tw.on('finish', function() {
-    // got the expected chunks
+    // Got the expected chunks
     assert.deepStrictEqual(tw.buffer, chunks);
   });
 
@@ -181,7 +181,7 @@ for (let i = 0; i < chunks.length; i++) {
       undefined ];
 
   tw.on('finish', function() {
-    // got the expected chunks
+    // Got the expected chunks
     assert.deepStrictEqual(tw.buffer, chunks);
   });
 
@@ -210,9 +210,9 @@ for (let i = 0; i < chunks.length; i++) {
 
   tw.on('finish', common.mustCall(function() {
     process.nextTick(common.mustCall(function() {
-      // got chunks in the right order
+      // Got chunks in the right order
       assert.deepStrictEqual(tw.buffer, chunks);
-      // called all callbacks
+      // Called all callbacks
       assert.deepStrictEqual(callbacks._called, chunks);
     }));
   }));
diff --git a/test/parallel/test-stream3-pause-then-read.js b/test/parallel/test-stream3-pause-then-read.js
index b86c0157062dfe..bfd8a2037323c7 100644
--- a/test/parallel/test-stream3-pause-then-read.js
+++ b/test/parallel/test-stream3-pause-then-read.js
@@ -56,7 +56,7 @@ function push() {
 
 read100();
 
-// first we read 100 bytes
+// First we read 100 bytes.
 function read100() {
   readn(100, onData);
 }
@@ -77,7 +77,7 @@ function readn(n, then) {
   })();
 }
 
-// Then we listen to some data events
+// Then we listen to some data events.
 function onData() {
   expectEndingData -= 100;
   console.error('onData');
@@ -85,24 +85,24 @@ function onData() {
   r.on('data', function od(c) {
     seen += c.length;
     if (seen >= 100) {
-      // seen enough
+      // Seen enough
       r.removeListener('data', od);
       r.pause();
       if (seen > 100) {
-        // oh no, seen too much!
-        // put the extra back.
+        // Oh no, seen too much!
+        // Put the extra back.
         const diff = seen - 100;
         r.unshift(c.slice(c.length - diff));
         console.error('seen too much', seen, diff);
       }
 
-      // Nothing should be lost in between
+      // Nothing should be lost in-between.
       setImmediate(pipeLittle);
     }
   });
 }
 
-// Just pipe 200 bytes, then unshift the extra and unpipe
+// Just pipe 200 bytes, then unshift the extra and unpipe.
 function pipeLittle() {
   expectEndingData -= 200;
   console.error('pipe a little');
@@ -130,14 +130,14 @@ function pipeLittle() {
   r.pipe(w);
 }
 
-// now read 1234 more bytes
+// Now read 1234 more bytes.
 function read1234() {
   readn(1234, resumePause);
 }
 
 function resumePause() {
   console.error('resumePause');
-  // Don't read anything, just resume and re-pause a whole bunch
+  // Don't read anything, just resume and re-pause a whole bunch.
   r.resume();
   r.pause();
   r.resume();
diff --git a/test/parallel/test-string-decoder-end.js b/test/parallel/test-string-decoder-end.js
index 0c0c072eb9d653..ee0a47e3572f6d 100644
--- a/test/parallel/test-string-decoder-end.js
+++ b/test/parallel/test-string-decoder-end.js
@@ -86,7 +86,7 @@ function testEncoding(encoding) {
 }
 
 function testBuf(encoding, buf) {
-  // write one byte at a time.
+  // Write one byte at a time.
   let s = new SD(encoding);
   let res1 = '';
   for (let i = 0; i < buf.length; i++) {
diff --git a/test/parallel/test-stringbytes-external.js b/test/parallel/test-stringbytes-external.js
index b66fb0960adf21..d64312f52540a7 100644
--- a/test/parallel/test-stringbytes-external.js
+++ b/test/parallel/test-stringbytes-external.js
@@ -30,7 +30,7 @@ let ucs2_control = 'a\u0000';
 let write_str = 'a';
 
 
-// first do basic checks
+// First do basic checks
 let b = Buffer.from(write_str, 'ucs2');
 // first check latin1
 let c = b.toString('latin1');
@@ -43,7 +43,7 @@ assert.strictEqual(b[0], 0x61);
 assert.strictEqual(b[1], 0);
 assert.strictEqual(ucs2_control, c);
 
-// now create big strings
+// Now create big strings
 const size = 1 << 20;
 write_str = write_str.repeat(size);
 ucs2_control = ucs2_control.repeat(size);
@@ -76,7 +76,7 @@ assert.strictEqual(c_bin.length, c_ucs.length);
 for (let i = 0; i < c_bin.length; i++) {
   assert.strictEqual(c_bin[i], c_ucs[i]);
 }
-// check resultant strings
+// Check resultant strings
 assert.strictEqual(c_bin.toString('ucs2'), c_ucs.toString('ucs2'));
 assert.strictEqual(c_bin.toString('latin1'), ucs2_control);
 assert.strictEqual(c_ucs.toString('latin1'), ucs2_control);
@@ -96,7 +96,7 @@ const PRE_3OF4_APEX = Math.ceil((EXTERN_APEX / 4) * 3) - RADIOS;
     const pumped_string2 = slice2.toString('hex');
     const decoded = Buffer.from(pumped_string, 'hex');
 
-    // the string are the same?
+    // The string are the same?
     for (let k = 0; k < pumped_string.length; ++k) {
       assert.strictEqual(pumped_string[k], pumped_string2[k]);
     }
@@ -117,7 +117,7 @@ const PRE_3OF4_APEX = Math.ceil((EXTERN_APEX / 4) * 3) - RADIOS;
     const pumped_string2 = slice2.toString('base64');
     const decoded = Buffer.from(pumped_string, 'base64');
 
-    // the string are the same?
+    // The string are the same?
     for (let k = 0; k < pumped_string.length - 3; ++k) {
       assert.strictEqual(pumped_string[k], pumped_string2[k]);
     }
diff --git a/test/parallel/test-timers-ordering.js b/test/parallel/test-timers-ordering.js
index 1f2809ab4e1831..6c6daecef3a563 100644
--- a/test/parallel/test-timers-ordering.js
+++ b/test/parallel/test-timers-ordering.js
@@ -44,7 +44,7 @@ function f(i) {
            `current ts ${now} < prev ts ${last_ts} + 1`);
     last_ts = now;
 
-    // schedule next iteration
+    // Schedule next iteration
     setTimeout(f, 1, i + 1);
   }
 }
diff --git a/test/parallel/test-timers-uncaught-exception.js b/test/parallel/test-timers-uncaught-exception.js
index 0a0eabf4c14e5b..8bcf72e36c730f 100644
--- a/test/parallel/test-timers-uncaught-exception.js
+++ b/test/parallel/test-timers-uncaught-exception.js
@@ -24,7 +24,7 @@ const common = require('../common');
 const assert = require('assert');
 const errorMsg = 'BAM!';
 
-// the first timer throws...
+// The first timer throws...
 setTimeout(common.mustCall(function() {
   throw new Error(errorMsg);
 }), 1);
diff --git a/test/parallel/test-tls-alpn-server-client.js b/test/parallel/test-tls-alpn-server-client.js
index 76604e05875c65..3da24c67fbe522 100644
--- a/test/parallel/test-tls-alpn-server-client.js
+++ b/test/parallel/test-tls-alpn-server-client.js
@@ -80,7 +80,7 @@ function Test1() {
     checkResults(results[1],
                  { server: { ALPN: 'b' },
                    client: { ALPN: 'b' } });
-    // nothing is selected by ALPN
+    // Nothing is selected by ALPN
     checkResults(results[2],
                  { server: { ALPN: false },
                    client: { ALPN: false } });
@@ -98,15 +98,15 @@ function Test2() {
   const clientsOptions = [{}, {}, {}];
 
   runTest(clientsOptions, serverOptions, function(results) {
-    // nothing is selected by ALPN
+    // Nothing is selected by ALPN
     checkResults(results[0],
                  { server: { ALPN: false },
                    client: { ALPN: false } });
-    // nothing is selected by ALPN
+    // Nothing is selected by ALPN
     checkResults(results[1],
                  { server: { ALPN: false },
                    client: { ALPN: false } });
-    // nothing is selected by ALPN
+    // Nothing is selected by ALPN
     checkResults(results[2],
                  { server: { ALPN: false },
                    client: { ALPN: false } });
diff --git a/test/parallel/test-tls-client-renegotiation-limit.js b/test/parallel/test-tls-client-renegotiation-limit.js
index 010fd8596aa0c8..38dcf5a80be5a6 100644
--- a/test/parallel/test-tls-client-renegotiation-limit.js
+++ b/test/parallel/test-tls-client-renegotiation-limit.js
@@ -34,7 +34,7 @@ const fixtures = require('../common/fixtures');
 // Renegotiation as a protocol feature was dropped after TLS1.2.
 tls.DEFAULT_MAX_VERSION = 'TLSv1.2';
 
-// renegotiation limits to test
+// Renegotiation limits to test
 const LIMITS = [0, 1, 2, 3, 5, 10, 16];
 
 {
@@ -87,7 +87,7 @@ function test(next) {
       assert.strictEqual(hadErr, false);
     });
 
-    // simulate renegotiation attack
+    // Simulate renegotiation attack
     function spam() {
       client.write('');
       client.renegotiate({}, (err) => {
diff --git a/test/parallel/test-tls-connect-memleak.js b/test/parallel/test-tls-connect-memleak.js
index 0278e6c7159a68..162d61fcdc7a66 100644
--- a/test/parallel/test-tls-connect-memleak.js
+++ b/test/parallel/test-tls-connect-memleak.js
@@ -50,7 +50,7 @@ const gcListener = { ongc() { collected = true; } };
     server.address().port,
     { rejectUnauthorized: false },
     common.mustCall(() => {
-      assert.strictEqual(gcObject, gcObject); // keep reference alive
+      assert.strictEqual(gcObject, gcObject); // Keep reference alive
       assert.strictEqual(collected, false);
       setImmediate(done, sock);
     }));
diff --git a/test/parallel/test-tls-ecdh-auto.js b/test/parallel/test-tls-ecdh-auto.js
index 840063229a60b7..7b535ecd3a18f0 100644
--- a/test/parallel/test-tls-ecdh-auto.js
+++ b/test/parallel/test-tls-ecdh-auto.js
@@ -26,7 +26,7 @@ const options = {
   ecdhCurve: 'auto'
 };
 
-const reply = 'I AM THE WALRUS'; // something recognizable
+const reply = 'I AM THE WALRUS'; // Something recognizable
 
 const server = tls.createServer(options, function(conn) {
   conn.end(reply);
diff --git a/test/parallel/test-tls-ecdh-multiple.js b/test/parallel/test-tls-ecdh-multiple.js
index d5f27a5e464437..1fcfc041bd4050 100644
--- a/test/parallel/test-tls-ecdh-multiple.js
+++ b/test/parallel/test-tls-ecdh-multiple.js
@@ -26,7 +26,7 @@ const options = {
   ecdhCurve: 'secp256k1:prime256v1:secp521r1'
 };
 
-const reply = 'I AM THE WALRUS'; // something recognizable
+const reply = 'I AM THE WALRUS'; // Something recognizable
 
 const server = tls.createServer(options, function(conn) {
   conn.end(reply);
diff --git a/test/parallel/test-tls-ecdh.js b/test/parallel/test-tls-ecdh.js
index e7d986cc9aec09..23767be92cf00c 100644
--- a/test/parallel/test-tls-ecdh.js
+++ b/test/parallel/test-tls-ecdh.js
@@ -41,7 +41,7 @@ const options = {
   ecdhCurve: 'prime256v1'
 };
 
-const reply = 'I AM THE WALRUS'; // something recognizable
+const reply = 'I AM THE WALRUS'; // Something recognizable
 
 const server = tls.createServer(options, common.mustCall(function(conn) {
   conn.end(reply);
diff --git a/test/parallel/test-tls-socket-close.js b/test/parallel/test-tls-socket-close.js
index 73130768890550..839be2a888973b 100644
--- a/test/parallel/test-tls-socket-close.js
+++ b/test/parallel/test-tls-socket-close.js
@@ -38,7 +38,7 @@ const tlsServer = tls.createServer({ cert, key }, (socket) => {
 let netSocket;
 // plain tcp server
 const netServer = net.createServer((socket) => {
-  // if client wants to use tls
+  // If client wants to use tls
   tlsServer.emit('connection', socket);
 
   netSocket = socket;
diff --git a/test/parallel/test-url-fileurltopath.js b/test/parallel/test-url-fileurltopath.js
index f6a1fb4fdafd01..74a217e8b68bde 100644
--- a/test/parallel/test-url-fileurltopath.js
+++ b/test/parallel/test-url-fileurltopath.js
@@ -53,9 +53,9 @@ assert.throws(() => url.fileURLToPath('https://a/b/c'), {
   let testCases;
   if (isWindows) {
     testCases = [
-      // lowercase ascii alpha
+      // Lowercase ascii alpha
       { path: 'C:\\foo', fileURL: 'file:///C:/foo' },
-      // uppercase ascii alpha
+      // Uppercase ascii alpha
       { path: 'C:\\FOO', fileURL: 'file:///C:/FOO' },
       // dir
       { path: 'C:\\dir\\foo', fileURL: 'file:///C:/dir/foo' },
@@ -91,16 +91,16 @@ assert.throws(() => url.fileURLToPath('https://a/b/c'), {
       { path: 'C:\\foo\rbar', fileURL: 'file:///C:/foo%0Dbar' },
       // latin1
       { path: 'C:\\fóóbàr', fileURL: 'file:///C:/f%C3%B3%C3%B3b%C3%A0r' },
-      // euro sign (BMP code point)
+      // Euro sign (BMP code point)
       { path: 'C:\\€', fileURL: 'file:///C:/%E2%82%AC' },
       // Rocket emoji (non-BMP code point)
       { path: 'C:\\🚀', fileURL: 'file:///C:/%F0%9F%9A%80' }
     ];
   } else {
     testCases = [
-      // lowercase ascii alpha
+      // Lowercase ascii alpha
       { path: '/foo', fileURL: 'file:///foo' },
-      // uppercase ascii alpha
+      // Uppercase ascii alpha
       { path: '/FOO', fileURL: 'file:///FOO' },
       // dir
       { path: '/dir/foo', fileURL: 'file:///dir/foo' },
@@ -136,7 +136,7 @@ assert.throws(() => url.fileURLToPath('https://a/b/c'), {
       { path: '/foo\rbar', fileURL: 'file:///foo%0Dbar' },
       // latin1
       { path: '/fóóbàr', fileURL: 'file:///f%C3%B3%C3%B3b%C3%A0r' },
-      // euro sign (BMP code point)
+      // Euro sign (BMP code point)
       { path: '/€', fileURL: 'file:///%E2%82%AC' },
       // Rocket emoji (non-BMP code point)
       { path: '/🚀', fileURL: 'file:///%F0%9F%9A%80' },
diff --git a/test/parallel/test-url-format.js b/test/parallel/test-url-format.js
index d18ff6715b3ed0..2d0132eb38a0bb 100644
--- a/test/parallel/test-url-format.js
+++ b/test/parallel/test-url-format.js
@@ -203,7 +203,7 @@ const formatTests = {
     pathname: '/fooA100%mBr',
   },
 
-  // multiple `#` in search
+  // Multiple `#` in search
   'http://example.com/?foo=bar%231%232%233&abc=%234%23%235#frag': {
     href: 'http://example.com/?foo=bar%231%232%233&abc=%234%23%235#frag',
     protocol: 'http:',
diff --git a/test/parallel/test-url-parse-format.js b/test/parallel/test-url-parse-format.js
index b318658febbaea..d802b0f6dcc3f6 100644
--- a/test/parallel/test-url-parse-format.js
+++ b/test/parallel/test-url-parse-format.js
@@ -157,7 +157,7 @@ const parseTests = {
     path: '/Y'
   },
 
-  // whitespace in the front
+  // Whitespace in the front
   ' http://www.example.com/': {
     href: 'http://www.example.com/',
     protocol: 'http:',
@@ -861,7 +861,7 @@ const parseTests = {
     href: 'http://a%0D%22%20%09%0A%3C\'b:b@c/%0D%0Ad/e?f'
   },
 
-  // git urls used by npm
+  // Git urls used by npm
   'git+ssh://git@github.com:npm/npm': {
     protocol: 'git+ssh:',
     slashes: true,
diff --git a/test/parallel/test-url-pathtofileurl.js b/test/parallel/test-url-pathtofileurl.js
index 1beb69b7f38343..395447ab4cef0d 100644
--- a/test/parallel/test-url-pathtofileurl.js
+++ b/test/parallel/test-url-pathtofileurl.js
@@ -27,9 +27,9 @@ const url = require('url');
   let testCases;
   if (isWindows) {
     testCases = [
-      // lowercase ascii alpha
+      // Lowercase ascii alpha
       { path: 'C:\\foo', expected: 'file:///C:/foo' },
-      // uppercase ascii alpha
+      // Uppercase ascii alpha
       { path: 'C:\\FOO', expected: 'file:///C:/FOO' },
       // dir
       { path: 'C:\\dir\\foo', expected: 'file:///C:/dir/foo' },
@@ -65,16 +65,16 @@ const url = require('url');
       { path: 'C:\\foo\rbar', expected: 'file:///C:/foo%0Dbar' },
       // latin1
       { path: 'C:\\fóóbàr', expected: 'file:///C:/f%C3%B3%C3%B3b%C3%A0r' },
-      // euro sign (BMP code point)
+      // Euro sign (BMP code point)
       { path: 'C:\\€', expected: 'file:///C:/%E2%82%AC' },
       // Rocket emoji (non-BMP code point)
       { path: 'C:\\🚀', expected: 'file:///C:/%F0%9F%9A%80' }
     ];
   } else {
     testCases = [
-      // lowercase ascii alpha
+      // Lowercase ascii alpha
       { path: '/foo', expected: 'file:///foo' },
-      // uppercase ascii alpha
+      // Uppercase ascii alpha
       { path: '/FOO', expected: 'file:///FOO' },
       // dir
       { path: '/dir/foo', expected: 'file:///dir/foo' },
@@ -110,7 +110,7 @@ const url = require('url');
       { path: '/foo\rbar', expected: 'file:///foo%0Dbar' },
       // latin1
       { path: '/fóóbàr', expected: 'file:///f%C3%B3%C3%B3b%C3%A0r' },
-      // euro sign (BMP code point)
+      // Euro sign (BMP code point)
       { path: '/€', expected: 'file:///%E2%82%AC' },
       // Rocket emoji (non-BMP code point)
       { path: '/🚀', expected: 'file:///%F0%9F%9A%80' },
diff --git a/test/parallel/test-url-relative.js b/test/parallel/test-url-relative.js
index dc0362df1a5662..d0c4b5f42c3e0c 100644
--- a/test/parallel/test-url-relative.js
+++ b/test/parallel/test-url-relative.js
@@ -4,7 +4,7 @@ const assert = require('assert');
 const inspect = require('util').inspect;
 const url = require('url');
 
-// when source is false
+// When source is false
 assert.strictEqual(url.resolveObject('', 'foo'), 'foo');
 
 /*
@@ -105,11 +105,11 @@ const relativeTests2 = [
   ['g/', bases[0], 'http://a/b/c/g/'],
   ['/g', bases[0], 'http://a/g'],
   ['//g', bases[0], 'http://g/'],
-  // changed with RFC 2396bis
+  // Changed with RFC 2396bis
   // ('?y', bases[0], 'http://a/b/c/d;p?y'],
   ['?y', bases[0], 'http://a/b/c/d;p?y'],
   ['g?y', bases[0], 'http://a/b/c/g?y'],
-  // changed with RFC 2396bis
+  // Changed with RFC 2396bis
   // ('#s', bases[0], CURRENT_DOC_URI + '#s'],
   ['#s', bases[0], 'http://a/b/c/d;p?q#s'],
   ['g#s', bases[0], 'http://a/b/c/g#s'],
@@ -117,7 +117,7 @@ const relativeTests2 = [
   [';x', bases[0], 'http://a/b/c/;x'],
   ['g;x', bases[0], 'http://a/b/c/g;x'],
   ['g;x?y#s', bases[0], 'http://a/b/c/g;x?y#s'],
-  // changed with RFC 2396bis
+  // Changed with RFC 2396bis
   // ('', bases[0], CURRENT_DOC_URI],
   ['', bases[0], 'http://a/b/c/d;p?q'],
   ['.', bases[0], 'http://a/b/c/'],
@@ -130,10 +130,10 @@ const relativeTests2 = [
   ['../../g', bases[0], 'http://a/g'],
   ['../../../g', bases[0], ('http://a/../g', 'http://a/g')],
   ['../../../../g', bases[0], ('http://a/../../g', 'http://a/g')],
-  // changed with RFC 2396bis
+  // Changed with RFC 2396bis
   // ('/./g', bases[0], 'http://a/./g'],
   ['/./g', bases[0], 'http://a/g'],
-  // changed with RFC 2396bis
+  // Changed with RFC 2396bis
   // ('/../g', bases[0], 'http://a/../g'],
   ['/../g', bases[0], 'http://a/g'],
   ['g.', bases[0], 'http://a/b/c/g.'],
@@ -162,7 +162,7 @@ const relativeTests2 = [
   ['g/', bases[1], 'http://a/b/c/g/'],
   ['/g', bases[1], 'http://a/g'],
   ['//g', bases[1], 'http://g/'],
-  // changed in RFC 2396bis
+  // Changed in RFC 2396bis
   // ('?y', bases[1], 'http://a/b/c/?y'],
   ['?y', bases[1], 'http://a/b/c/d;p?y'],
   ['g?y', bases[1], 'http://a/b/c/g?y'],
@@ -200,9 +200,9 @@ const relativeTests2 = [
   ['g', bases[3], 'fred:///s//a/b/g'],
   ['./g', bases[3], 'fred:///s//a/b/g'],
   ['g/', bases[3], 'fred:///s//a/b/g/'],
-  ['/g', bases[3], 'fred:///g'],  // may change to fred:///s//a/g
-  ['//g', bases[3], 'fred://g'],   // may change to fred:///s//g
-  ['//g/x', bases[3], 'fred://g/x'], // may change to fred:///s//g/x
+  ['/g', bases[3], 'fred:///g'],  // May change to fred:///s//a/g
+  ['//g', bases[3], 'fred://g'],   // May change to fred:///s//g
+  ['//g/x', bases[3], 'fred://g/x'], // May change to fred:///s//g/x
   ['///g', bases[3], 'fred:///g'],
   ['./', bases[3], 'fred:///s//a/b/'],
   ['../', bases[3], 'fred:///s//a/'],
@@ -220,9 +220,9 @@ const relativeTests2 = [
   ['g', bases[4], 'http:///s//a/b/g'],
   ['./g', bases[4], 'http:///s//a/b/g'],
   ['g/', bases[4], 'http:///s//a/b/g/'],
-  ['/g', bases[4], 'http:///g'],  // may change to http:///s//a/g
-  ['//g', bases[4], 'http://g/'],   // may change to http:///s//g
-  ['//g/x', bases[4], 'http://g/x'], // may change to http:///s//g/x
+  ['/g', bases[4], 'http:///g'],  // May change to http:///s//a/g
+  ['//g', bases[4], 'http://g/'],   // May change to http:///s//g
+  ['//g/x', bases[4], 'http://g/x'], // May change to http:///s//g/x
   ['///g', bases[4], 'http:///g'],
   ['./', bases[4], 'http:///s//a/b/'],
   ['../', bases[4], 'http:///s//a/'],
diff --git a/test/parallel/test-util-callbackify.js b/test/parallel/test-util-callbackify.js
index 9be3b132f95172..c381924e1b5f9d 100644
--- a/test/parallel/test-util-callbackify.js
+++ b/test/parallel/test-util-callbackify.js
@@ -89,7 +89,7 @@ const values = [
       }
     }));
 
-    // test a Promise factory
+    // Test a Promise factory
     function promiseFn() {
       return Promise.reject(value);
     }
diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
index a474fd56e44b71..d8739de790d0ad 100644
--- a/test/parallel/test-util-inspect.js
+++ b/test/parallel/test-util-inspect.js
@@ -1787,7 +1787,7 @@ assert.strictEqual(util.inspect('"\'${a}'), "'\"\\'${a}'");
   assert.strictEqual(util.inspect(date),
                      '{ CustomDate 2010-02-14T11:48:40.000Z foo: \'bar\' }');
 
-  // check for null prototype
+  // Check for null prototype
   Object.setPrototypeOf(date, null);
   assert.strictEqual(util.inspect(date),
                      '{ [Date: null prototype] 2010-02-14T11:48:40.000Z' +
@@ -1812,7 +1812,7 @@ assert.strictEqual(util.inspect('"\'${a}'), "'\"\\'${a}'");
   assert.strictEqual(util.inspect(date),
                      '{ CustomDate Invalid Date foo: \'bar\' }');
 
-  // check for null prototype
+  // Check for null prototype
   Object.setPrototypeOf(date, null);
   assert.strictEqual(util.inspect(date),
                      '{ [Date: null prototype] Invalid Date foo: \'bar\' }');
diff --git a/test/parallel/test-util-isDeepStrictEqual.js b/test/parallel/test-util-isDeepStrictEqual.js
index 071e612565938a..1ad64c2ff81a57 100644
--- a/test/parallel/test-util-isDeepStrictEqual.js
+++ b/test/parallel/test-util-isDeepStrictEqual.js
@@ -221,7 +221,7 @@ notUtilIsDeepStrict(
   new Map([['1', 5], [0, 5], ['0', 5]])
 );
 
-// undefined value in Map
+// Undefined value in Map
 utilIsDeepStrict(
   new Map([[1, undefined]]),
   new Map([[1, undefined]])
diff --git a/test/parallel/test-v8-coverage.js b/test/parallel/test-v8-coverage.js
index f002604c48e594..02ace7af9cdd78 100644
--- a/test/parallel/test-v8-coverage.js
+++ b/test/parallel/test-v8-coverage.js
@@ -29,7 +29,7 @@ function nextdir() {
   assert.strictEqual(output.stderr.toString(), '');
   const fixtureCoverage = getFixtureCoverage('basic.js', coverageDirectory);
   assert.ok(fixtureCoverage);
-  // first branch executed.
+  // First branch executed.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[0].count, 1);
   // Second branch did not execute.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[1].count, 0);
@@ -48,7 +48,7 @@ function nextdir() {
   assert.strictEqual(output.stderr.toString(), '');
   const fixtureCoverage = getFixtureCoverage('exit-1.js', coverageDirectory);
   assert.ok(fixtureCoverage, 'coverage not found for file');
-  // first branch executed.
+  // First branch executed.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[0].count, 1);
   // Second branch did not execute.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[1].count, 0);
@@ -69,7 +69,7 @@ function nextdir() {
   assert.strictEqual(output.stderr.toString(), '');
   const fixtureCoverage = getFixtureCoverage('sigint.js', coverageDirectory);
   assert.ok(fixtureCoverage);
-  // first branch executed.
+  // First branch executed.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[0].count, 1);
   // Second branch did not execute.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[1].count, 0);
@@ -89,13 +89,13 @@ function nextdir() {
   const fixtureCoverage = getFixtureCoverage('subprocess.js',
                                              coverageDirectory);
   assert.ok(fixtureCoverage);
-  // first branch executed.
+  // First branch executed.
   assert.strictEqual(fixtureCoverage.functions[1].ranges[0].count, 1);
   // Second branch did not execute.
   assert.strictEqual(fixtureCoverage.functions[1].ranges[1].count, 0);
 }
 
-// outputs coverage from worker.
+// Outputs coverage from worker.
 {
   const coverageDirectory = path.join(tmpdir.path, nextdir());
   const output = spawnSync(process.execPath, [
@@ -109,7 +109,7 @@ function nextdir() {
   const fixtureCoverage = getFixtureCoverage('subprocess.js',
                                              coverageDirectory);
   assert.ok(fixtureCoverage);
-  // first branch executed.
+  // First branch executed.
   assert.strictEqual(fixtureCoverage.functions[1].ranges[0].count, 1);
   // Second branch did not execute.
   assert.strictEqual(fixtureCoverage.functions[1].ranges[1].count, 0);
@@ -145,7 +145,7 @@ function nextdir() {
   const fixtureCoverage = getFixtureCoverage('async-hooks.js',
                                              coverageDirectory);
   assert.ok(fixtureCoverage);
-  // first branch executed.
+  // First branch executed.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[0].count, 1);
 }
 
@@ -167,7 +167,7 @@ function nextdir() {
   const fixtureCoverage = getFixtureCoverage('basic.js',
                                              absoluteCoverageDirectory);
   assert.ok(fixtureCoverage);
-  // first branch executed.
+  // First branch executed.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[0].count, 1);
   // Second branch did not execute.
   assert.strictEqual(fixtureCoverage.functions[0].ranges[1].count, 0);
diff --git a/test/parallel/test-vm-global-property-interceptors.js b/test/parallel/test-vm-global-property-interceptors.js
index 23c56018b62e1f..01ae72446047f9 100644
--- a/test/parallel/test-vm-global-property-interceptors.js
+++ b/test/parallel/test-vm-global-property-interceptors.js
@@ -60,7 +60,7 @@ assert.deepEqual(result, {
   g: undefined
 });
 
-// define new properties
+// Define new properties
 vm.runInContext(`
 Object.defineProperty(this, 'h', {value: 'h'});
 Object.defineProperty(this, 'i', {});
diff --git a/test/parallel/test-whatwg-url-custom-properties.js b/test/parallel/test-whatwg-url-custom-properties.js
index ee51efd5390292..1fbc3ab6238ea3 100644
--- a/test/parallel/test-whatwg-url-custom-properties.js
+++ b/test/parallel/test-whatwg-url-custom-properties.js
@@ -9,7 +9,7 @@ const assert = require('assert');
 const urlToOptions = require('internal/url').urlToOptions;
 
 const url = new URL('http://user:pass@foo.bar.com:21/aaa/zzz?l=24#test');
-const oldParams = url.searchParams;  // for test of [SameObject]
+const oldParams = url.searchParams;  // For test of [SameObject]
 
 // To retrieve enumerable but not necessarily own properties,
 // we need to use the for-in loop.
diff --git a/test/parallel/test-zlib-invalid-input.js b/test/parallel/test-zlib-invalid-input.js
index 9b22df477840cb..68fa3825b91ced 100644
--- a/test/parallel/test-zlib-invalid-input.js
+++ b/test/parallel/test-zlib-invalid-input.js
@@ -54,6 +54,6 @@ unzips.forEach(common.mustCall((uz, i) => {
   uz.on('error', common.mustCall());
   uz.on('end', common.mustNotCall);
 
-  // this will trigger error event
+  // This will trigger error event
   uz.write('this is not valid compressed data.');
 }, unzips.length));
diff --git a/test/parallel/test-zlib-random-byte-pipes.js b/test/parallel/test-zlib-random-byte-pipes.js
index 0816e047bb0eef..d8d039a6d65c4f 100644
--- a/test/parallel/test-zlib-random-byte-pipes.js
+++ b/test/parallel/test-zlib-random-byte-pipes.js
@@ -46,7 +46,7 @@ class RandomReadStream extends Stream {
     // base block size.
     opt.block = opt.block || 256 * 1024;
 
-    // total number of bytes to emit
+    // Total number of bytes to emit
     opt.total = opt.total || 256 * 1024 * 1024;
     this._remaining = opt.total;
 
diff --git a/test/parallel/test-zlib-truncated.js b/test/parallel/test-zlib-truncated.js
index d8a04d3c0cc0cf..304f76b9da8651 100644
--- a/test/parallel/test-zlib-truncated.js
+++ b/test/parallel/test-zlib-truncated.js
@@ -38,12 +38,12 @@ const errMessage = /unexpected end of file/;
       assert.strictEqual(toUTF8(result), inputString);
     });
 
-    // sync truncated input test
+    // Sync truncated input test
     assert.throws(function() {
       zlib[methods.decompSync](truncated);
     }, errMessage);
 
-    // async truncated input test
+    // Async truncated input test
     zlib[methods.decomp](truncated, function(err, result) {
       assert(errMessage.test(err.message));
     });
diff --git a/test/parallel/test-zlib.js b/test/parallel/test-zlib.js
index 1852ae33936452..509dcd2207e83e 100644
--- a/test/parallel/test-zlib.js
+++ b/test/parallel/test-zlib.js
@@ -44,7 +44,7 @@ let trickle = [128, 1024, 1024 * 1024];
 // several different chunk sizes
 let chunkSize = [128, 1024, 1024 * 16, 1024 * 1024];
 
-// this is every possible value.
+// This is every possible value.
 let level = [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
 let windowBits = [8, 9, 10, 11, 12, 13, 14, 15];
 let memLevel = [1, 2, 3, 4, 5, 6, 7, 8, 9];
@@ -74,7 +74,7 @@ testFiles.forEach(common.mustCall((file) => {
 }, testFiles.length));
 
 
-// stream that saves everything
+// Stream that saves everything
 class BufferStream extends stream.Stream {
   constructor() {
     super();
@@ -210,7 +210,7 @@ testKeys.forEach(common.mustCall((file) => {
                   }
                 }));
 
-                // the magic happens here.
+                // The magic happens here.
                 ss.pipe(def).pipe(inf).pipe(buf);
                 ss.end(test);
               }, zlibPairs.length));
diff --git a/test/pummel/test-fs-watch-file.js b/test/pummel/test-fs-watch-file.js
index 70e793938ac2d3..7a8854860c15f1 100644
--- a/test/pummel/test-fs-watch-file.js
+++ b/test/pummel/test-fs-watch-file.js
@@ -41,7 +41,7 @@ const filenameTwo = 'hasOwnProperty';
 const filepathTwo = filenameTwo;
 const filepathTwoAbs = path.join(testDir, filenameTwo);
 
-const filenameThree = 'charm'; // because the third time is
+const filenameThree = 'charm'; // Because the third time is
 
 const filenameFour = 'get';
 
diff --git a/test/pummel/test-timers.js b/test/pummel/test-timers.js
index 8a8646b3237f90..60d6a7e6922836 100644
--- a/test/pummel/test-timers.js
+++ b/test/pummel/test-timers.js
@@ -43,7 +43,7 @@ setTimeout(common.mustCall(function() {
   assert.strictEqual(1000 - WINDOW < diff && diff < 1000 + WINDOW, true);
 }), 1000);
 
-// this timer shouldn't execute
+// This timer shouldn't execute
 const id = setTimeout(function() { assert.strictEqual(true, false); }, 500);
 clearTimeout(id);
 
diff --git a/test/sequential/test-child-process-emfile.js b/test/sequential/test-child-process-emfile.js
index e81b3a0ffec9cb..7e31792f9dfb31 100644
--- a/test/sequential/test-child-process-emfile.js
+++ b/test/sequential/test-child-process-emfile.js
@@ -64,7 +64,7 @@ proc.on('error', common.mustCall(function(err) {
 
 proc.on('exit', common.mustNotCall('"exit" event should not be emitted'));
 
-// close one fd for LSan
+// Close one fd for LSan
 if (openFds.length >= 1) {
   fs.closeSync(openFds.pop());
 }
diff --git a/test/sequential/test-cli-syntax-bad.js b/test/sequential/test-cli-syntax-bad.js
index 1512d9df4f1605..8298157a57e16e 100644
--- a/test/sequential/test-cli-syntax-bad.js
+++ b/test/sequential/test-cli-syntax-bad.js
@@ -35,7 +35,7 @@ const syntaxErrorRE = /^SyntaxError: \b/m;
       assert.strictEqual(err.code, 1,
                          `code ${err.code} !== 1 for error:\n\n${err}`);
 
-      // no stdout should be produced
+      // No stdout should be produced
       assert.strictEqual(stdout, '');
 
       // Stderr should have a syntax error message
diff --git a/test/sequential/test-cli-syntax-file-not-found.js b/test/sequential/test-cli-syntax-file-not-found.js
index b3bb9723e2c78e..3e1f3ec56118b3 100644
--- a/test/sequential/test-cli-syntax-file-not-found.js
+++ b/test/sequential/test-cli-syntax-file-not-found.js
@@ -27,7 +27,7 @@ const notFoundRE = /^Error: Cannot find module/m;
     const _args = args.concat(file);
     const cmd = [node, ..._args].join(' ');
     exec(cmd, common.mustCall((err, stdout, stderr) => {
-      // no stdout should be produced
+      // No stdout should be produced
       assert.strictEqual(stdout, '');
 
       // `stderr` should have a module not found error message.
diff --git a/test/sequential/test-cli-syntax-require.js b/test/sequential/test-cli-syntax-require.js
index d99dc2ff71a9f1..c309b1f4556c3f 100644
--- a/test/sequential/test-cli-syntax-require.js
+++ b/test/sequential/test-cli-syntax-require.js
@@ -11,7 +11,7 @@ const node = process.execPath;
 // depending on the JavaScript engine.
 const syntaxErrorRE = /^SyntaxError: \b/m;
 
-// should work with -r flags
+// Should work with -r flags
 ['-c', '--check'].forEach(function(checkFlag) {
   ['-r', '--require'].forEach(function(requireFlag) {
     const preloadFile = fixtures.path('no-wrapper.js');
@@ -23,7 +23,7 @@ const syntaxErrorRE = /^SyntaxError: \b/m;
       assert.strictEqual(err.code, 1,
                          `code ${err.code} !== 1 for error:\n\n${err}`);
 
-      // no stdout should be produced
+      // No stdout should be produced
       assert.strictEqual(stdout, '');
 
       // stderr should have a syntax error message
diff --git a/test/sequential/test-http-keepalive-maxsockets.js b/test/sequential/test-http-keepalive-maxsockets.js
index 53d67b24797770..9c98a140f6a134 100644
--- a/test/sequential/test-http-keepalive-maxsockets.js
+++ b/test/sequential/test-http-keepalive-maxsockets.js
@@ -47,7 +47,7 @@ server.listen(0, function() {
     assert.strictEqual(count(agent.sockets), 0);
     assert.strictEqual(serverSockets.length, 5);
 
-    // now make 10 more reqs.
+    // Now make 10 more reqs.
     // should use the 2 free reqs from the pool first.
     makeReqs(10, function(er) {
       assert.ifError(er);
diff --git a/test/sequential/test-stream2-stderr-sync.js b/test/sequential/test-stream2-stderr-sync.js
index 68d35dbdbc6a91..7384cf6e74f502 100644
--- a/test/sequential/test-stream2-stderr-sync.js
+++ b/test/sequential/test-stream2-stderr-sync.js
@@ -53,7 +53,7 @@ function child0() {
   console.error('baz');
 }
 
-// using process.stderr
+// Using process.stderr
 function child1() {
   process.stderr.write('child 1\n');
   process.stderr.write('foo\n');
diff --git a/tools/eslint-rules/required-modules.js b/tools/eslint-rules/required-modules.js
index 5175d4d46d7e95..f22b14caac4183 100644
--- a/tools/eslint-rules/required-modules.js
+++ b/tools/eslint-rules/required-modules.js
@@ -11,7 +11,7 @@ const path = require('path');
 //------------------------------------------------------------------------------
 
 module.exports = function(context) {
-  // trim required module names
+  // Trim required module names
   const requiredModules = context.options;
   const isESM = context.parserOptions.sourceType === 'module';
 
diff --git a/tools/test-npm-package.js b/tools/test-npm-package.js
index 0cf9700ef96e80..b34b8183677211 100755
--- a/tools/test-npm-package.js
+++ b/tools/test-npm-package.js
@@ -30,7 +30,7 @@ const nodePath = path.dirname(process.execPath);
 
 function spawnCopyDeepSync(source, destination) {
   if (common.isWindows) {
-    mkdirSync(destination); // prevent interactive prompt
+    mkdirSync(destination); // Prevent interactive prompt
     return spawnSync('xcopy.exe', ['/E', source, destination]);
   } else {
     return spawnSync('cp', ['-r', `${source}/`, destination]);