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, 20 insertions, 36 deletions

diff --git a/test/parallel/test-timers-throw-when-cb-not-function.js b/test/parallel/test-timers-throw-when-cb-not-function.js
index 2aff904f06..4e866726c1 100644
--- a/test/parallel/test-timers-throw-when-cb-not-function.js
+++ b/test/parallel/test-timers-throw-when-cb-not-function.js
@@ -8,18 +8,14 @@ function doSetTimeout(callback, after) {
   };
 }
 
-assert.throws(doSetTimeout('foo'),
-              /"callback" argument must be a function/);
-assert.throws(doSetTimeout({foo: 'bar'}),
-              /"callback" argument must be a function/);
-assert.throws(doSetTimeout(),
-              /"callback" argument must be a function/);
-assert.throws(doSetTimeout(undefined, 0),
-              /"callback" argument must be a function/);
-assert.throws(doSetTimeout(null, 0),
-              /"callback" argument must be a function/);
-assert.throws(doSetTimeout(false, 0),
-              /"callback" argument must be a function/);
+const errMessage = /"callback" argument must be a function/;
+
+assert.throws(doSetTimeout('foo'), errMessage);
+assert.throws(doSetTimeout({foo: 'bar'}), errMessage);
+assert.throws(doSetTimeout(), errMessage);
+assert.throws(doSetTimeout(undefined, 0), errMessage);
+assert.throws(doSetTimeout(null, 0), errMessage);
+assert.throws(doSetTimeout(false, 0), errMessage);
 
 
 function doSetInterval(callback, after) {
@@ -28,18 +24,12 @@ function doSetInterval(callback, after) {
   };
 }
 
-assert.throws(doSetInterval('foo'),
-              /"callback" argument must be a function/);
-assert.throws(doSetInterval({foo: 'bar'}),
-              /"callback" argument must be a function/);
-assert.throws(doSetInterval(),
-              /"callback" argument must be a function/);
-assert.throws(doSetInterval(undefined, 0),
-              /"callback" argument must be a function/);
-assert.throws(doSetInterval(null, 0),
-              /"callback" argument must be a function/);
-assert.throws(doSetInterval(false, 0),
-              /"callback" argument must be a function/);
+assert.throws(doSetInterval('foo'), errMessage);
+assert.throws(doSetInterval({foo: 'bar'}), errMessage);
+assert.throws(doSetInterval(), errMessage);
+assert.throws(doSetInterval(undefined, 0), errMessage);
+assert.throws(doSetInterval(null, 0), errMessage);
+assert.throws(doSetInterval(false, 0), errMessage);
 
 
 function doSetImmediate(callback, after) {
@@ -48,15 +38,9 @@ function doSetImmediate(callback, after) {
   };
 }
 
-assert.throws(doSetImmediate('foo'),
-              /"callback" argument must be a function/);
-assert.throws(doSetImmediate({foo: 'bar'}),
-              /"callback" argument must be a function/);
-assert.throws(doSetImmediate(),
-              /"callback" argument must be a function/);
-assert.throws(doSetImmediate(undefined, 0),
-              /"callback" argument must be a function/);
-assert.throws(doSetImmediate(null, 0),
-              /"callback" argument must be a function/);
-assert.throws(doSetImmediate(false, 0),
-              /"callback" argument must be a function/);
+assert.throws(doSetImmediate('foo'), errMessage);
+assert.throws(doSetImmediate({foo: 'bar'}), errMessage);
+assert.throws(doSetImmediate(), errMessage);
+assert.throws(doSetImmediate(undefined, 0), errMessage);
+assert.throws(doSetImmediate(null, 0), errMessage);
+assert.throws(doSetImmediate(false, 0), errMessage);