Allow settings `hooks` key in `pubspec_overrides.yaml`

[robertbastian]

They way we use these in dart-lang/i18n and unicode-org/icu4x is for local development, they shouldn't necessarily be published, so it would make sense to move them into overrides.

[sigurdm]

@dcharkes where is the hooks key documented? Isn't the hook key for builds/tasks that happens on the package consumers side?

[dcharkes]

I wasn't aware that you cannot publish a package with a hooks toplevel key. Thanks for the report @robertbastian.
We have an allowlist somewhere? @sigurdm

Yes, the hooks key for non-root-packages doesn't do anything. Or more specifically the user-defines key inside hooks. (We might add some other stuff under hooks that would be effective in the future.) However, there's one exception to this: If your published package has an executables section and is meant to be dart installed, then having a hooks->user-defines in your pubspec.yaml is fine.

Allowing hooks->user-defines in pubspec_overrides.yaml sgtm.
And allowing hooks->user-defines in pubspec.yaml if executables. (Not sure if our allowlist logic can do this.)

[robertbastian]

I wasn't aware that you cannot publish a package with a hooks toplevel key

Oh I haven't actually tried this and didn't mean to imply that. I just think it'd be better to support them in overrides so for example when we try different arguments in CI we don't have to mess with the real pubspec.

[dcharkes]

Ah, yes, I think we don't support it in pubspec_overrides.yaml, but I think it makes sense to support that. Let me file a separate issue for that.

[robertbastian]

That's what this issue was meant to be 😃