How do you unit test mixins in Dart?

Question

I can find no documentation on this. The only way I see is to test a class that has the mixin added, but this is not a sound way of testing.

Answer 1

/// example mixin
///
mixin TestMixin {
  String testing(String abc) {
    print("your function logic goes here");
    return abc;
  }
}

/// This is just a helper class to get all the [mixin] functions
///
class FunctionHoldingClassForMixin with TestMixin {}

Now you can use this in main function as shown below.

void main() {
  late FunctionHoldingClassForMixin mockClass;
  setUp(() {
    mockClass = FunctionHoldingClassForMixin();
  });

  test("mention what you wanna test", () {
    var result = mockClass.testing("testing abc");
    expect(result, "testing abc");
  });
}

• Hope this resolves your equery 👨‍💻.
• In case if someone finds a better approach do comment to improve the answer.
• Thank you 😅