pkg/analyzer/test/src/diagnostics/unnecessary_null_check_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(UnnecessaryNullCheckPatternTest);
  });
}

@reflectiveTest
class UnnecessaryNullCheckPatternTest extends PubPackageResolutionTest {
  test_interfaceType_nonNullable() async {
    await assertErrorsInCode('''
void f(int x) {
  if (x case var a?) {}
}
''', [
      error(WarningCode.UNUSED_LOCAL_VARIABLE, 33, 1),
      error(StaticWarningCode.UNNECESSARY_NULL_CHECK_PATTERN, 34, 1),
    ]);
  }

  test_interfaceType_nullable() async {
    await assertErrorsInCode('''
void f(int? x) {
  if (x case var a?) {}
}
''', [
      error(WarningCode.UNUSED_LOCAL_VARIABLE, 34, 1),
    ]);
  }

  test_typeParameter_nonNullable() async {
    await assertErrorsInCode('''
class A<T extends num> {
  void f(T x) {
    if (x case var a?) {}
  }
}
''', [
      error(WarningCode.UNUSED_LOCAL_VARIABLE, 60, 1),
      error(StaticWarningCode.UNNECESSARY_NULL_CHECK_PATTERN, 61, 1),
    ]);
  }

  test_typeParameter_nullable() async {
    await assertErrorsInCode('''
class A<T> {
  void f(T x) {
    if (x case var a?) {}
  }
}
''', [
      error(WarningCode.UNUSED_LOCAL_VARIABLE, 48, 1),
    ]);
  }
}