Apply `directives_ordering` to `part`

[FMorschel]

Describe the issue There is the directives_ordering. It does not apply to part, only import and export.

To Reproduce

• Create a simple project.
• Ensure directives_ordering is being used:

linter:
  rules:
    directives_ordering: true

• Create 2 new files a.dart and b.dart inside lib.
• Make them part of main.dart:

part 'b.dart';
part 'a.dart';

Expected behavior To trigger directives_ordering lint.

Additional context If you disagree with adding this rule to directives_ordering, then maybe we could create a new linter to that.

[bwilkerson]

It does seem reasonable to me that the lint should check part directives.

[pq]

Chatting w/ @jakemac53, sorting parts is not something we can safely do in a world with augmentations because then order matters.

Because of that, I don't think we want to go ahead with this after all.

[FMorschel]

I'm not familiar with augmentations yet, but can't the analyzer see if this is being used to apply the suggestion only when it is not? Or would it be weird to do so?

[jakemac53]

Fwiw, it is possible to determine when it is safe to do. But, implementing that might not be worth while (or spending the compute on it). It is safe if any of the following are true:

• If none of the parts have augmenting declarations
• The augmenting declarations only introduce new members (and don't alter existing ones)
• Any existing member which is augmented, is only augmented once.

But, it doesn't feel right for this lint to be computing all of that, when today it can operate on just a single parsed AST.

[FMorschel]

Thats understandable. Could you please link here some docs for augmentations so I can see what you are talking about? And if there is nothing else you'd like to discuss here we can close this issue.

[jakemac53]

https://github.com/dart-lang/language/blob/main/working/augmentation-libraries/feature-specification.md