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, 2 deletions

diff --git a/test/parallel/test-fs-options-immutable.js b/test/parallel/test-fs-options-immutable.js
index 185d14c472..5f43a334f8 100644
--- a/test/parallel/test-fs-options-immutable.js
+++ b/test/parallel/test-fs-options-immutable.js
@@ -63,12 +63,14 @@ if (!common.isAix) {
   // https://github.com/nodejs/node/issues/5085 is fixed
   {
     let watch;
-    assert.doesNotThrow(() => watch = fs.watch(__filename, options, () => {}));
+    assert.doesNotThrow(() => {
+      watch = fs.watch(__filename, options, common.noop);
+    });
     watch.close();
   }
 
   {
-    assert.doesNotThrow(() => fs.watchFile(__filename, options, () => {}));
+    assert.doesNotThrow(() => fs.watchFile(__filename, options, common.noop));
     fs.unwatchFile(__filename);
   }
 }