refactor(lint/useEnumInitializers): make code fix safe

[Conaclos]

Summary

No bugs were reported for useEnumInitializers.
Moreover, its code fix doesn't change the program behavior.

Test Plan

I updated the snapshots and added more tests.

[ematipico]

Personally, I don't agree.

We're changing the value of an enum. If the user is already using the values somewhere, we'll break the user's code.

In the documentation we suggest a = Blue value, which will change from 0 to a string "Blue". This is super unsafe, especially if the user is using that value in other files, for example inside a switch or if.

[Conaclos]

We're changing the value of an enum. If the user is already using the values somewhere, we'll break the user's code.

In the documentation we suggest a = Blue value, which will change from 0 to a string "Blue". This is super unsafe, especially if the user is using that value in other files, for example inside a switch or if.

In TypeScript, the following enum is invalid:

enum Color {
  Red = "Red",
  Green = "Green",
  Blue,
}

In fact, all suggestions of strings are made for invalid enums.
The idea is to provide code suggestions while someone is typing the enum.

For integer-valued enums, I designed the code fix such as it suggests only the actual value of the enum member.
Thus, it is safe.

However, I accept that changing an enum member in such a way that an invalid enum (producing a compiler error), now compiles is questionable.
We could either keep the fix unsafe, or remove the suggestion for string enum members.
What do you think?

EDIT: After a second though, I think we should not suggest any code fix for invalid enum members. We could remove string suggestions and make the code fix safe.

[ematipico]

Thank you for providing such a good explanation, your contextual knowledge is very valuable.

I'm sold, let's ship it!