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, 5 deletions

diff --git a/test/parallel/test-net-socket-timeout.js b/test/parallel/test-net-socket-timeout.js
index e29f9e1472..0319e18173 100644
--- a/test/parallel/test-net-socket-timeout.js
+++ b/test/parallel/test-net-socket-timeout.js
@@ -25,10 +25,9 @@ const net = require('net');
 const assert = require('assert');
 
 // Verify that invalid delays throw
-const noop = function() {};
 const s = new net.Socket();
 const nonNumericDelays = [
-  '100', true, false, undefined, null, '', {}, noop, []
+  '100', true, false, undefined, null, '', {}, common.noop, []
 ];
 const badRangeDelays = [-0.001, -1, -Infinity, Infinity, NaN];
 const validDelays = [0, 0.001, 1, 1e6];
@@ -36,19 +35,19 @@ const validDelays = [0, 0.001, 1, 1e6];
 
 for (let i = 0; i < nonNumericDelays.length; i++) {
   assert.throws(function() {
-    s.setTimeout(nonNumericDelays[i], noop);
+    s.setTimeout(nonNumericDelays[i], common.noop);
   }, TypeError);
 }
 
 for (let i = 0; i < badRangeDelays.length; i++) {
   assert.throws(function() {
-    s.setTimeout(badRangeDelays[i], noop);
+    s.setTimeout(badRangeDelays[i], common.noop);
   }, RangeError);
 }
 
 for (let i = 0; i < validDelays.length; i++) {
   assert.doesNotThrow(function() {
-    s.setTimeout(validDelays[i], noop);
+    s.setTimeout(validDelays[i], common.noop);
   });
 }