src: namespace config file flags

[marco-ippolito]

follow-up: #57016 (comment)

[marco-ippolito]

🤔 no code-owners... wonder who I should ping, or create a team

[codecov]

Codecov Report

Attention: Patch coverage is 96.66667% with 2 lines in your changes missing coverage. Please review.

Project coverage is 90.35%. Comparing base (8fc919d) to head (c9fe4d6).
Report is 565 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_config_file.cc	95.65%	2 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@## main #57170 +/- ##
=======================================
Coverage 90.35% 90.35% =======================================
Files 629 629 Lines 184308 184394 +86 Branches 36015 36027 +12 =======================================
+ Hits 166532 166617 +85 + Misses 10909 10902 -7 - Partials 6867 6875 +8 

Files with missing lines	Coverage Δ
lib/internal/options.js	100.00% <100.00%> (ø)
src/node_config_file.cc	71.96% <95.65%> (+8.94%)	⬆️

... and 25 files with indirect coverage changes

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[BridgeAR]

I would rather not use the namespace and just specify a specific file that we use instead of letting the user define the filename.

[marco-ippolito]

I would rather not use the namespace and just specify a specific file that we use instead of letting the user define the filename.

I added the default file in #57171, about namespacing I think its a necessary evil, otherwise we will regret it if the feature grows

[GeoffreyBooth]

🤔 no code-owners... wonder who I should ping, or create a team

I think we need a @nodejs/cli team or something, to cover this feature and --env-file. Please add me if you create one.

[GeoffreyBooth]

There was discussion in old issues about supporting various environments, like top-level fields such as dev or localhost or prod etc. I don't have an opinion as to how multiple environments or multiple config files should be handled, but I feel like this is something to be worked out now as we're discussing namespacing. If the answer is that we're just not going to provide any explicit support for merging config files or supporting multiple environments within one config file, that's fine, but I think we should have that discussion.

[GeoffreyBooth]

Can we support all of experimental-transform-types, experimental_transform_types and experimentalTransformTypes for each flag? Just as currently the CLI supports either of the first two.

[marco-ippolito]

I'm ok with the second, not sure how feasible is the third one. I think we can defer to a followup

[robpalme]

Given this is just a sample of how to use the config file to persist flags, would it be better to stick to non-experimental flags?

This example maximizes hiding of the dependency on experimental features, e.g. by disabling the warnings too. That's fine if you are experienced enough to understand the implications.

Whilst it's certainly possible to use configs for this purpose, having it as the shining model example seems risky IMO and may be construed as encouragement to use this pattern.

[marco-ippolito]

will do in the followup PR #57171 since this is ready to land and we have added the not-land-on-v23

[marco-ippolito]

I dont think we should support different environments in the same file, users can use the dev.config.json and the prod.config.json

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/65372/ 💛