proposal: function_expression_with_incorrect_types

[a14n]

function_expression_with_incorrect_types

Description

Use the parameter types expected by the target in function expression.

Details

With always_specify_types you have to add type annotations on everything. With function expressions it's always a code smell to have a type that doesn't match the declared parameter types.

Kind

Avoiding code smell.

Bad Examples

f(void Function(int a) p) {}

f((int? a) {});
f((num a) {});

Good Examples

f(void Function(int a) p) {}

f((a) {});
f((int a) {});

Discussion

At the time of the creation of this lint implementation (#2530) there were several diagnostics in Flutter codebase.

Discussion checklist

• List any existing rules this proposal modifies, complements, overlaps or conflicts with.
• List any relevant issues (reported here, the SDK Tracker, or elsewhere).
• If there's any prior art (e.g., in other linters), please add references here.
• If this proposal corresponds to Effective Dart or Flutter Style Guide advice, please call it out. (If there isn't any corresponding advice, should there be?)
• If this proposal is motivated by real-world examples, please provide as many details as you can. Demonstrating potential impact is especially valuable.