iterable_contains_unrelated_type not working for List

[davidmorgan]

In IntelliJ, I see this triggers the lint:

  Iterable<int> foo = [1];
  print(foo.contains('3'));

and this:

  Set<int> foo = Set.from([1]);
  print(foo.contains('3'));

but not this:

  List<int> foo = [1];
  print(foo.contains('3'));

I'm at a loss as to why not; it looks like there are test cases that should catch this in the linter code, and they pass. Maybe there is something in the test setup that is now different from the actual List?

[alexeieleusis]

I just tried adding the example you provide and the test fails, also confirmed that if I remove the // LINT annotation the test fails, so is definitely being linted in the tests. If I run dart bin/linter.dart --rules=iterable_contains_unrelated_type test/rules/iterable_contains_unrelated_type.dart the lint is not reported.

I have no idea what the problem is :(

[pq]

Maybe there is something in the test setup that is now different from the actual List?

👍

We mock the SDK to speed up testing and it looks like List is out of date:

https://github.com/dart-lang/linter/blob/9f3df652baa88372513f1ac74148b8e7a5a6d1a0/test/mock_sdk.dart#L125-L134

(In the SDK, List implements EfficientLengthIterable<E>)

[pq]

/cc @alexeieleusis

[lambda-fairy]

I think the issue is that unrelated_types_visitor only checks interfaces, and not superclass or mixins.

Indeed, in the SDK List<T> extends EfficientLengthIterable, not implements.

Perhaps replacing that bespoke method with a call to getImplementedInterfaces would fix the bug.

[lambda-fairy]

I take that back -- after changing the mock List<T> to extend an intermediate EfficientLengthIterable class, the tests still pass 🤔

NB: The mock SDK has been moved to the analyzer package.

[xvrh]

I think the lint iterable_contains_unrelated_type is still broken. The examples don't trigger the lint in my project.

dart --version
Dart SDK version: 2.12.1 (stable) (Wed Mar 10 10:18:47 2021 +0100) on "macos_x64"

// main.dart
void someFunction() {
  var list = <int>[];
  if (list.contains('1')) print('someFunction');
}

# analysis_options.yaml
linter:
  rules:
    - iterable_contains_unrelated_type

dart analyze
No issues found!