Deprecate containsSemantics in favor of isSemantics

The containsSemantics partial matcher is deprecated and replaced by isSemantics to clarify intent and standardize matcher conventions.

The contains prefix for partial matchers, such as containsSemantics, has been replaced with is to align with naming conventions:

• Partial matchers (e.g. isSemantics) match only the properties explicitly provided. Any arguments not provided are ignored.
• Exact matchers (e.g. matchesSemantics) verify all values. Any arguments not provided are expected to match the object's default values.

To automatically migrate your code, run the following command:

dart fix --apply

Alternatively, replace containsSemantics with isSemantics for partial matching (most common case), or matchesSemantics if you need to assert exact property values (including defaults for omitted arguments).

Code before migration:

expect(
  tester.getSemantics(find.byType(MyWidget)),
  containsSemantics(
    label: 'My Widget',
    isButton: true,
  ),
);

Code after migration:

expect(
  tester.getSemantics(find.byType(MyWidget)),
  isSemantics(
    label: 'My Widget',
    isButton: true,
  ),
);

Landed in version: 3.40.0-1.0.pre In stable release: 3.40

API documentation:

• isSemantics
• matchesSemantics

Relevant issues:

• Issue 180534
• Issue 107859

Relevant PR:

• PR 180538