src: add validation for CLI options that don't take an argument

[npaun]

Certain command-line options don't take an argument. Among them are --watch and --check. However, as @dario-piotrowicz points out in #57864, Node's argument parser will silently accept an argument for boolean flags, admitting inputs like --watch=this-value-should-not-be-here.js, which creates user confusion.

In this PR, I worked together with @dario-piotrowicz to add an error message if an argument is mistakenly provided for boolean flags.

[dario-piotrowicz]

Looks good to me 😄

But ideally some tests should be added for this 🙂

[codecov]

Codecov Report

❌ Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.84%. Comparing base (7178e91) to head (804d180).
⚠️ Report is 1674 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_options-inl.h	80.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #59584      +/-   ##
==========================================
+ Coverage   89.83%   89.84%   +0.01%     
==========================================
  Files         666      666              
  Lines      195337   195341       +4     
  Branches    38353    38358       +5     
==========================================
+ Hits       175474   175511      +37     
+ Misses      12323    12296      -27     
+ Partials     7540     7534       -6     

Files with missing lines	Coverage Δ
src/node_options-inl.h	82.84% <80.00%> (-0.12%)	⬇️

... and 43 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[dario-piotrowicz]

@npaun There are tests failures, the problem being that there are tests that pass a boolean to the --watch flag, as in --watch=true:
https://github.com/nodejs/node/blame/f86b652bc8beec4aea778bfc621781264dfb6c6a/test/sequential/test-watch-mode.mjs#L167

I think you need to update the line I shared above not to include the =true to get the tests to pass (unless there are other such failures)

---

Anyways the above worries me a bit because I can imagine users also potentially (and incorrectly) using --watch=true (note: the value passed to --watch does not matter anyways, for example --watch=false does not disable watch mode), because of this I would lean to be a bit more cautious here and maybe make this a semver major change, what do you think @jasnell?

(Alternatively the change here could be made to accept true (for enabling) and false (for disabling) boolean flags, that would not need to be a semver major change in my opinion)

[github-actions]

This pull request has been marked as stale due to 210 days of inactivity.
It will be automatically closed in 30 days if no further activity occurs. If this is still relevant, please leave a comment or update it to keep it open.