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, 1 insertions, 1 deletions

diff --git a/test/parallel/test-process-emitwarning.js b/test/parallel/test-process-emitwarning.js
index 61ca05cfe9..d2d090eae3 100644
--- a/test/parallel/test-process-emitwarning.js
+++ b/test/parallel/test-process-emitwarning.js
@@ -12,7 +12,7 @@ const testType = 'CustomWarning';
 
 process.on('warning', common.mustCall((warning) => {
   assert(warning);
-  assert(/^(Warning|CustomWarning)/.test(warning.name));
+  assert(/^(?:Warning|CustomWarning)/.test(warning.name));
   assert.strictEqual(warning.message, testMsg);
   if (warning.code) assert.strictEqual(warning.code, testCode);
   if (warning.detail) assert.strictEqual(warning.detail, testDetail);