pkg/analyzer/test/src/diagnostics/unnecessary_cast_pattern_test.dart

// Copyright (c) 2023, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:analyzer/src/error/codes.dart';
import 'package:test_reflective_loader/test_reflective_loader.dart';

import '../dart/resolution/context_collection_resolution.dart';

main() {
  defineReflectiveSuite(() {
    defineReflectiveTests(UnnecessaryCastPatternTest);
  });
}

@reflectiveTest
class UnnecessaryCastPatternTest extends PubPackageResolutionTest {
  test_matchedIsSameAsRequired() async {
    await assertErrorsInCode(r'''
void f(int x) {
  if (x case var z as int) {}
}
''', [
      error(WarningCode.UNUSED_LOCAL_VARIABLE, 33, 1),
      error(WarningCode.UNNECESSARY_CAST_PATTERN, 35, 2),
    ]);
  }

  test_matchedIsSubtypeOfRequired() async {
    await assertErrorsInCode(r'''
void f(int x) {
  if (x case var z as num) {}
}
''', [
      error(WarningCode.UNUSED_LOCAL_VARIABLE, 33, 1),
      error(WarningCode.UNNECESSARY_CAST_PATTERN, 35, 2),
    ]);
  }

  test_matchedIsSupertypeOfRequired() async {
    await assertErrorsInCode(r'''
void f(num x) {
  if (x case var z as int) {}
}
''', [
      error(WarningCode.UNUSED_LOCAL_VARIABLE, 33, 1),
    ]);
  }

  test_matchedIsUnrelatedToRequired() async {
    await assertErrorsInCode(r'''
class A {}
class B {}

void f(A x) {
  if (x case var z as B) {}
}
''', [
      error(WarningCode.UNUSED_LOCAL_VARIABLE, 54, 1),
    ]);
  }
}