test: remove unnecessary assignments

common.js needs to be loaded in all tests so that there is checking
for variable leaks and possibly other things. However, it does not
need to be assigned to a variable if nothing in common.js is referred
to elsewhere in the test.

The main tradeoff for this bit of code churn is that it gets the code
base most of the way to being able to enable the no-unused-vars rule in
eslint.

(The non-tooling benefit is that it lessens cognitive load when reading
tests as it is an immediate indication that none of the functions or
properties in common.js will be used by the test.)

PR-URL: #4563
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

test/internet/test-dns-txt-sigsegv.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var dns = require('dns');
 

test/internet/test-dns.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert'),
     dns = require('dns'),
     net = require('net'),

test/internet/test-http-dns-fail.js

@@ -4,7 +4,7 @@
  * should trigger the error event after each attempt.
  */
 
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 

test/internet/test-net-connect-timeout.js

@@ -3,7 +3,7 @@
 // https://groups.google.com/forum/#!topic/nodejs/UE0ZbfLt6t8
 // https://groups.google.com/forum/#!topic/nodejs-dev/jR7-5UDqXkw
 
-var common = require('../common');
+require('../common');
 var net = require('net');
 var assert = require('assert');
 

test/internet/test-net-connect-unref.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var net = require('net');
 

test/message/2100bytes.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var util = require('util');
 

test/message/core_line_numbers.js

@@ -1,5 +1,5 @@
 'use strict';
-const common = require('../common');
+require('../common');
 const punycode = require('punycode');
 
 // This test verifies that line numbers in core modules are reported correctly.

test/message/error_exit.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 process.on('exit', function(code) {

test/message/eval_messages.js

@@ -1,6 +1,6 @@
 'use strict';
 
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var spawn = require('child_process').spawn;

test/message/hello_world.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 console.log('hello world');

test/message/max_tick_depth.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 
 process.maxTickDepth = 10;
 var i = 20;

test/message/nexttick_throw.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 process.nextTick(function() {

test/message/stack_overflow.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 Error.stackTraceLimit = 0;

test/message/stdin_messages.js

@@ -1,6 +1,6 @@
 'use strict';
 
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var spawn = require('child_process').spawn;

test/message/throw_custom_error.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 // custom error throwing

test/message/throw_in_line_with_tabs.js

@@ -1,6 +1,6 @@
 /* eslint-disable indent */
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 console.error('before');

test/message/throw_non_error.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 // custom error throwing

test/message/throw_null.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 throw null;

test/message/throw_undefined.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 throw undefined;

test/message/timeout_throw.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 setTimeout(function() {

test/message/undefined_reference_in_new_context.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var vm = require('vm');
 

test/message/vm_display_runtime_error.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var vm = require('vm');
 

test/message/vm_dont_display_syntax_error.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var vm = require('vm');
 

test/parallel/test-async-wrap-throw-no-init.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const async_wrap = process.binding('async_wrap');
 

test/parallel/test-buffer-arraybuffer.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 
 const Buffer = require('buffer').Buffer;

test/parallel/test-buffer-ascii.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 // ASCII conversion in node.js simply masks off the high bits,

test/parallel/test-buffer-bytelength.js

@@ -1,6 +1,6 @@
 'use strict';
 
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var Buffer = require('buffer').Buffer;
 

test/parallel/test-buffer-concat.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var zero = [];

test/parallel/test-buffer-fakes.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const Buffer = require('buffer').Buffer;
 const Bp = Buffer.prototype;

test/parallel/test-buffer-indexof.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var Buffer = require('buffer').Buffer;

test/parallel/test-buffer-inheritance.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 
 

test/parallel/test-buffer-inspect.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var util = require('util');

test/parallel/test-buffer-iterator.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var buffer = new Buffer([1, 2, 3, 4, 5]);

test/parallel/test-buffer-slow.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const buffer = require('buffer');
 const Buffer = buffer.Buffer;

test/parallel/test-child-process-constructor.js

@@ -1,7 +1,7 @@
 'use strict';
 
+require('../common');
 var assert = require('assert');
-var common = require('../common');
 var child_process = require('child_process');
 var ChildProcess = child_process.ChildProcess;
 assert.equal(typeof ChildProcess, 'function');

test/parallel/test-child-process-detached.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var path = require('path');
 

test/parallel/test-child-process-fork-and-spawn.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var spawn = require('child_process').spawn;
 var fork = require('child_process').fork;

test/parallel/test-child-process-fork-ref.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var fork = require('child_process').fork;
 

test/parallel/test-child-process-fork-ref2.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var fork = require('child_process').fork;
 

test/parallel/test-child-process-internal.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 //messages

test/parallel/test-child-process-set-blocking.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var ch = require('child_process');
 

test/parallel/test-child-process-silent.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var childProcess = require('child_process');
 

test/parallel/test-child-process-spawnsync-env.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var cp = require('child_process');
 

test/parallel/test-child-process-spawnsync-timeout.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var spawnSync = require('child_process').spawnSync;

test/parallel/test-child-process-stdin-ipc.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var spawn = require('child_process').spawn;

test/parallel/test-child-process-stdio-big-write-end.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var BUFSIZE = 1024;
 

test/parallel/test-child-process-validate-stdio.js

@@ -1,8 +1,8 @@
 'use strict';
 // Flags: --expose_internals
 
+require('../common');
 var assert = require('assert');
-var common = require('../common');
 var _validateStdio = require('internal/child_process')._validateStdio;
 
 // should throw if string and not ignore, pipe, or inherit

test/parallel/test-cluster-debug-port.js

@@ -1,5 +1,5 @@
 'use strict';
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const cluster = require('cluster');
 

test/parallel/test-cluster-fork-env.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var cluster = require('cluster');
 

test/parallel/test-cluster-setup-master-cumulative.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var cluster = require('cluster');
 

test/parallel/test-cluster-setup-master-emit.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var cluster = require('cluster');
 

test/parallel/test-cluster-setup-master-multiple.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var cluster = require('cluster');
 

test/parallel/test-cluster-setup-master.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var cluster = require('cluster');
 

test/parallel/test-cluster-uncaught-exception.js

@@ -3,7 +3,7 @@
 // one that the cluster module installs.
 // https://github.com/joyent/node/issues/2556
 
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var cluster = require('cluster');
 var fork = require('child_process').fork;