remove deprecated lints in 3.0

[pq]

3.0 would be a good time to remove deprecated lints.

Candidates:

• remove avoid_as #4005
• remove invariant_booleans #4009
• remove prefer_bool_in_asserts #4012
• remove prefer_equal_for_default_values #4013
• remove super_goes_last #4014
• remove enable_null_safety #4020
  • (replaced by Analyzer doesn't error on legacy libraries sdk#50694)

[srawlins]

I think enable_null_safety should also be removed in 3.0. This rule is being replaced by dart-lang/sdk#50694.

[srawlins]

I'd also like to remove avoid_null_checks_in_equality_operators, which mostly doesn't make sense under null safety, with a proposed rule: equality_operator_override_with_nullable_parameter

[srawlins]

None of these have to do with null safety, so they can be deleted even before Google internal is null safe.

(The last one, enable_null_safety, does obviously pertain to null safety, but is not used internally, so it can also be deleted.)

[mit-mit]

Can we also remove default_list_constructor ?

[mit-mit]

Also, how is the present issue different from dart-lang/lints#95 ?

[pq]

Can we also remove default_list_constructor ?

I think so? @bwilkerson?

Also, how is the present issue different from dart-lang/lints#95 ?

This issue tracks the removal of the lint implementations from the linter. dart-lang/lints#95 is about removing newly removed/deprecated lints from the published lint sets.

[bwilkerson]

The default_list_constructor diagnostic is a compile-time error, not a lint, but I believe that we can remove it. It won't be reported in 3.0 because it looks for invocations of the default constructor, but the default constructor is gone so there can't be an invocation of it (the error instead is "The class 'List' doesn't have an unnamed constructor.").

[pq]

Closing linter side as complete.