src: add setTitle() as alternative to direct assignment

[JonathanLopes404]

Implement process.setTitle(title) as a new function-based API for setting the process title, complementing the existing process.title property assignment pattern

Fixes: #62797

[nodejs-github-bot]

Review requested:

• @nodejs/startup

[addaleax]

Why does this introduce a new native method? Adding the new API is fine, but it should just trigger the same code paths.

[JonathanLopes404]

@addaleax Updated in latest commit: setTitle now reuses the existing process.title path (removed native method). Could you please take another look?

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/72786/

[codecov]

Codecov Report

❌ Patch coverage is 88.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.30%. Comparing base (c3de450) to head (8896c78).
⚠️ Report is 10 commits behind head on main.

Files with missing lines	Patch %	Lines
...l/bootstrap/switches/does_not_own_process_state.js	78.57%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #62804      +/-   ##
==========================================
- Coverage   90.31%   90.30%   -0.01%     
==========================================
  Files         759      759              
  Lines      248312   248345      +33     
  Branches    46861    46866       +5     
==========================================
+ Hits       224265   224276      +11     
- Misses      15476    15510      +34     
+ Partials     8571     8559      -12     

Files with missing lines	Coverage Δ
...ernal/bootstrap/switches/does_own_process_state.js	95.48% <100.00%> (+0.34%)	⬆️
...l/bootstrap/switches/does_not_own_process_state.js	94.23% <78.57%> (-5.77%)	⬇️

... and 37 files with indirect coverage changes

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[silverwind]

Would add a reference on bottom of the process.title docs to point to the new alternative.

[ljharb]

I'm confused why an alias for x => { process.title = x } is helpful - if it were an entirely new method, such that one could eventually deprecate the assignment form, that'd be one thing.

Separately, is it expected that if i Object.defineProperty(process, 'title', { writable: false, configurable: false }), setTitle will throw?

[JonathanLopes404]

Hello @ljharb,

Regarding the usefulness: the primary motivation is to support modern ESM usage. Since ESM bindings are read-only, users cannot do import { title } from 'node:process'; title = 'new'. By providing setTitle, we allow developers to use named exports effectively without needing to import the entire process object, which aligns with how other modern APIs are being shaped.

About Object.defineProperty:
Yes, it is expected to throw. Since wrappedSetTitle internally performs process.title = title, it will respect the property descriptors of process.title. If the property is made non-writable or non-configurable, the setter will throw a TypeError, maintaining consistency with the current behavior of the process object.

[silverwind]

I checked if there are more similar APIs that would need similar treatment and process.title appears to be the only setter API in the whole Node API, so it's complete treatment for the topic.

A deprecation of process.title could also be considered, maybe not now, but for the future.

[ljharb]

Fair point on the ESM usage.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/72928/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/72997/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/73553/

[silverwind]

Need to resolve merge conflicts, otherwise I think this is good to merge.

[jasnell]

I guess I'm not super convinced this is worthwhile, especially given that process is a global. The destructuring argument just isn't all that convincing to me.

Not going to block, but if the change is made, I'd prefer to go all in and fully replace process.title with process.getTitle()/process.setTitle() (or make process.title read-only with process.setTitle()) and deprecate the process.title setter.

[silverwind]

I strive to never use globals and prefer to import process explicitely, so from my perspective, it is a wart in the API.

Deprecation seems acceptable as this is a low-use API.

And I agree to adding getTitle(), it's needed because with a import {title} from "node:process" is not a live binding.

[JonathanLopes404]

Thanks for the feedback. I've updated the documentation to mark process.title as deprecated and added the getTitle method as requested.