test: rename regression tests more expressively

PR-URL: nodejs#19495
Refs: nodejs#19105
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-arm-math-exp-regress-1376.js → test/parallel/test-arm-math-illegal-instruction.js

@@ -1,8 +1,11 @@
 'use strict';
+require('../common');
+
+// This test ensures Math functions don't fail with an "illegal instruction"
+// error on ARM devices (primarily on the Raspberry Pi 1)
 // See https://github.com/nodejs/node/issues/1376
 // and https://code.google.com/p/v8/issues/detail?id=4019
 
-require('../common');
 Math.abs(-0.5);
 Math.acos(-0.5);
 Math.acosh(-0.5);

test/parallel/test-buffer-regression-649.js → test/parallel/test-buffer-tostring-rangeerror.js

@@ -1,10 +1,13 @@
 'use strict';
-
 const common = require('../common');
+
+// This test ensures that Node.js throws a RangeError when trying to convert a
+// gigantic buffer into a string.
+// Regression test for https://github.com/nodejs/node/issues/649.
+
 const assert = require('assert');
 const SlowBuffer = require('buffer').SlowBuffer;
 
-// Regression test for https://github.com/nodejs/node/issues/649.
 const len = 1422561062959;
 const message = common.expectsError({
   code: 'ERR_INVALID_OPT_VALUE',

test/parallel/test-dgram-regress-4496.js → test/parallel/test-dgram-send-invalid-msg-type.js

@@ -20,9 +20,12 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-// Remove this test once we support sending strings.
-
 require('../common');
+
+// This test ensures that a TypeError is raised when the argument to `send()`
+// or `sendto()` is anything but a Buffer.
+// https://github.com/nodejs/node-v0.x-archive/issues/4496
+
 const assert = require('assert');
 const dgram = require('dgram');
 

test/parallel/test-dns-regress-7070.js → test/parallel/test-dns-resolvens-typeerror.js

@@ -21,18 +21,25 @@
 
 'use strict';
 const common = require('../common');
-const dns = require('dns');
 
-// Should not raise assertion error.
+// This test ensures `dns.resolveNs()` does not raise a C++-land assertion error
+// and throw a JavaScript TypeError instead.
 // Issue https://github.com/nodejs/node-v0.x-archive/issues/7070
-common.expectsError(() => dns.resolveNs([]), // bad name
-                    {
-                      code: 'ERR_INVALID_ARG_TYPE',
-                      type: TypeError,
-                      message: /^The "name" argument must be of type string/
-                    });
-common.expectsError(() => dns.resolveNs(''), // bad callback
-                    {
-                      code: 'ERR_INVALID_CALLBACK',
-                      type: TypeError
-                    });
+
+const dns = require('dns');
+
+common.expectsError(
+  () => dns.resolveNs([]), // bad name
+  {
+    code: 'ERR_INVALID_ARG_TYPE',
+    type: TypeError,
+    message: /^The "name" argument must be of type string/
+  }
+);
+common.expectsError(
+  () => dns.resolveNs(''), // bad callback
+  {
+    code: 'ERR_INVALID_CALLBACK',
+    type: TypeError
+  }
+);

test/parallel/test-http-agent-maxsockets-respected.js

@@ -0,0 +1,56 @@
+'use strict';
+const common = require('../common');
+const Countdown = require('../common/countdown');
+
+// This test ensures that the `maxSockets` value for `http.Agent` is respected.
+// https://github.com/nodejs/node/issues/4050
+
+const assert = require('assert');
+const http = require('http');
+
+const MAX_SOCKETS = 2;
+
+const agent = new http.Agent({
+  keepAlive: true,
+  keepAliveMsecs: 1000,
+  maxSockets: MAX_SOCKETS,
+  maxFreeSockets: 2
+});
+
+const server = http.createServer(
+  common.mustCall((req, res) => {
+    res.end('hello world');
+  }, 6)
+);
+
+const countdown = new Countdown(6, () => server.close());
+
+function get(path, callback) {
+  return http.get(
+    {
+      host: 'localhost',
+      port: server.address().port,
+      agent: agent,
+      path: path
+    },
+    callback
+  );
+}
+
+server.listen(
+  0,
+  common.mustCall(() => {
+    for (let i = 0; i < 6; i++) {
+      const request = get('/1', common.mustCall());
+      request.on(
+        'response',
+        common.mustCall(() => {
+          request.abort();
+          const sockets = agent.sockets[Object.keys(agent.sockets)[0]];
+          assert(sockets.length <= MAX_SOCKETS);
+          countdown.dec();
+        })
+      );
+    }
+  })
+);