test: fix RegExp nits

* Remove needless RegExp flag

  In fixed case, `/g` flag is needless in the boolean context.

* Remove needless RegExp capturing

  Use non-capturing grouping or remove capturing completely when:

  * capturing is useless per se, e.g. in test() check;
  * captured groups are not used afterward at all;
  * some of the later captured groups are not used afterward.

* Use test, not match/exec in boolean context

  match() and exec() return a complicated object,
  unneeded in a boolean context.

* Do not needlessly repeat RegExp creation

  This commit takes RegExp creation out of cycles and other repetitions.

  As long as the RegExp does not use /g flag and match indices,
  we are safe here.

  In tests, this fix hardly gives a significant performance gain,
  but it increases clarity and maintainability,
  reassuring some RegExps to be identical.

  RegExp in functions are not taken out of their functions:
  while these functions are called many times
  and their RegExps are recreated with each call,
  the performance gain in test cases
  does not seem to be worth decreasing function self-dependency.

PR-URL: https://github.com/nodejs/node/pull/13770
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/test/sequential/test-module-loading.js b/test/sequential/test-module-loading.js
index c55c03279e..8a7bfe15c4 100644
--- a/test/sequential/test-module-loading.js
+++ b/test/sequential/test-module-loading.js
@@ -25,6 +25,8 @@ const assert = require('assert');
 const path = require('path');
 const fs = require('fs');
 
+const backslash = /\\/g;
+
 console.error('load test-module-loading.js');
 
 // assert that this is the main module.
@@ -195,7 +197,7 @@ try {
     require(`${loadOrder}file3`);
   } catch (e) {
     // Not a real .node module, but we know we require'd the right thing.
-    assert.ok(e.message.replace(/\\/g, '/').match(/file3\.node/));
+    assert.ok(/file3\.node/.test(e.message.replace(backslash, '/')));
   }
   assert.strictEqual(require(`${loadOrder}file4`).file4, 'file4.reg', msg);
   assert.strictEqual(require(`${loadOrder}file5`).file5, 'file5.reg2', msg);
@@ -203,7 +205,7 @@ try {
   try {
     require(`${loadOrder}file7`);
   } catch (e) {
-    assert.ok(e.message.replace(/\\/g, '/').match(/file7\/index\.node/));
+    assert.ok(/file7\/index\.node/.test(e.message.replace(backslash, '/')));
   }
   assert.strictEqual(require(`${loadOrder}file8`).file8, 'file8/index.reg',
                      msg);
@@ -237,7 +239,7 @@ try {
 
   const children = module.children.reduce(function red(set, child) {
     let id = path.relative(path.dirname(__dirname), child.id);
-    id = id.replace(/\\/g, '/');
+    id = id.replace(backslash, '/');
     set[id] = child.children.reduce(red, {});
     return set;
   }, {});