test: fix test/pummel/test-fs-watch-file.js

test-fs-watch-file.js fails for two reasons. First, there are cases where it is checking the error message for an error whose message has changed since the test was written. Change these instances to check for an error code instead. Second, there is an instance where it tries to remove a listener but fails because `common.mustNotCall()` returns a differnet instance of a function on each call. Store the function in a variable name so it can be removed as a listener on a file. PR-URL: #25384 Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Author: Trott

test/pummel/test-fs-watch-file.js

@@ -60,12 +60,8 @@ process.on('exit', function() {
 fs.writeFileSync(filepathOne, 'hello');
 
 assert.throws(
- function() {
- fs.watchFile(filepathOne);
- },
- function(e) {
- return e.message === '"watchFile()" requires a listener function';
- }
+ () => { fs.watchFile(filepathOne); },
+ { code: 'ERR_INVALID_ARG_TYPE' }
 );
 
 // Does not throw.
@@ -84,12 +80,8 @@ process.chdir(testDir);
 fs.writeFileSync(filepathTwoAbs, 'howdy');
 
 assert.throws(
- function() {
- fs.watchFile(filepathTwo);
- },
- function(e) {
- return e.message === '"watchFile()" requires a listener function';
- }
+ () => { fs.watchFile(filepathTwo); },
+ { code: 'ERR_INVALID_ARG_TYPE' }
 );
 
 { // Does not throw.
@@ -114,9 +106,10 @@ setTimeout(function() {
  fs.unwatchFile(filenameThree, b);
  ++watchSeenThree;
  }
- fs.watchFile(filenameThree, common.mustNotCall());
+ const uncalledListener = common.mustNotCall();
+ fs.watchFile(filenameThree, uncalledListener);
  fs.watchFile(filenameThree, b);
- fs.unwatchFile(filenameThree, common.mustNotCall());
+ fs.unwatchFile(filenameThree, uncalledListener);
 }
 
 setTimeout(function() {