[dart fix] support fixes for deprecated lints in options

[pq]

Expected behavior: dart fix fixes deprecated lints in analysis_options.yaml files where possible, by:

• removing them, or possibly
• replacing them with another preferred lint (see discussion below)

Note: currently we have a simple diagnostic code DEPRECATED_LINT_HINT but we may want to support more to support the different kinds of fixes would be appropriate.

[Cat-sushi]

Will we get warnings as well?

[pq]

@Cat-sushi: you should already see warnings for deprecated lints.

For example:

There's also a quick-fix to remove them but bulk-fixing options files is not wired into dart fix just yet.

[bwilkerson]

I have a small concern with this proposal.

If the lint has been deprecated because it no longer makes sense (such as the removal of the API being checked), then it makes sense to me to remove it when the language feature can no longer be opted out of.

But if the lint has been deprecated in favor of another lint (such as a more general lint or even a renamed version of the old lint), then it doesn't make sense to remove it; it should instead be updated (or the user should be required to decide whether they want the behavior of the new lint without the tool opting them into to a more general lint).

Perhaps the right answer is that we need something more nuanced that 'deprecated' for some kinds of lint changes, and that this fix is fine for the more restricted meaning of 'deprecated'.

[pq]

Great points!

[I]f the lint has been deprecated in favor of another lint (such as a more general lint or even a renamed version of the old lint)

I was thinking renames would be different than deprecations but another way to think of them is as a special kind of deprecation. In that case,

Perhaps the right answer is that we need something more nuanced that 'deprecated' for some kinds of lint changes, and that this fix is fine for the more restricted meaning of 'deprecated'.

💯

The more I think about it, the more I like the idea of a nuanced deprecation since that would afford some flexibility down the road.