test: add common.noop, default for common.mustCall()

Export a new common.noop no-operation function for general use.
Allow using common.mustCall() without a fn argument to simplify
test cases.

Replace various non-op functions throughout tests with common.noop

PR-URL: https://github.com/nodejs/node/pull/12027
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Teddy Katz <teddy.katz@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>

1 files changed, 4 insertions, 10 deletions

diff --git a/test/parallel/test-fs-empty-readStream.js b/test/parallel/test-fs-empty-readStream.js
index 85c38a61d0..73658d9757 100644
--- a/test/parallel/test-fs-empty-readStream.js
+++ b/test/parallel/test-fs-empty-readStream.js
@@ -33,11 +33,9 @@ fs.open(emptyFile, 'r', common.mustCall((error, fd) => {
 
   const read = fs.createReadStream(emptyFile, { fd });
 
-  read.once('data', () => {
-    common.fail('data event should not emit');
-  });
+  read.once('data', common.mustNotCall('data event should not emit'));
 
-  read.once('end', common.mustCall(function endEvent1() {}));
+  read.once('end', common.mustCall());
 }));
 
 fs.open(emptyFile, 'r', common.mustCall((error, fd) => {
@@ -48,13 +46,9 @@ fs.open(emptyFile, 'r', common.mustCall((error, fd) => {
 
   read.pause();
 
-  read.once('data', () => {
-    common.fail('data event should not emit');
-  });
+  read.once('data', common.mustNotCall('data event should not emit'));
 
-  read.once('end', function endEvent2() {
-    common.fail('end event should not emit');
-  });
+  read.once('end', common.mustNotCall('end event should not emit'));
 
   setTimeout(common.mustCall(() => {
     assert.strictEqual(read.isPaused(), true);