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

// Copyright (c) 2019, 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/driver_resolution.dart';

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

@reflectiveTest
class UnnecessaryCastTest extends DriverResolutionTest {
  test_conditionalExpression_changesResultType_left() async {
    await assertNoErrorsInCode(r'''
class A {}
class B extends A {}

dynamic f(bool c, B x, B y) {
  return c ? x as A : y;
}
''');
  }

  test_conditionalExpression_changesResultType_right() async {
    await assertNoErrorsInCode(r'''
class A {}
class B extends A {}

dynamic f(bool c, B x, B y) {
  return c ? x : y as A;
}
''');
  }

  test_conditionalExpression_leftDynamic_rightUnnecessary() async {
    await assertErrorsInCode(r'''
dynamic f(bool c, int a, int b) {
  return c ? a : b as int;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 51, 8),
    ]);
  }

  test_conditionalExpression_leftUnnecessary() async {
    await assertErrorsInCode(r'''
dynamic f(bool c, int a, int b) {
  return c ? a as int : b;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 47, 8),
    ]);
  }

  test_conditionalExpression_leftUnnecessary_rightDynamic() async {
    await assertErrorsInCode(r'''
dynamic f(bool c, int a, dynamic b) {
  return c ? a as int : b;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 51, 8),
    ]);
  }

  test_conditionalExpression_leftUnnecessary_rightUnnecessary() async {
    await assertErrorsInCode(r'''
dynamic f(bool c, int a, int b) {
  return c ? a as int : b as int;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 47, 8),
      error(HintCode.UNNECESSARY_CAST, 58, 8),
    ]);
  }

  test_conditionalExpression_rightUnnecessary() async {
    await assertErrorsInCode(r'''
dynamic f(bool c, int a, int b) {
  return c ? a : b as int;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 51, 8),
    ]);
  }

  test_dynamic_type() async {
    await assertNoErrorsInCode(r'''
void f(a) {
  a as Object;
}
''');
  }

  test_function() async {
    await assertNoErrorsInCode(r'''
void f() {
  Function(Null) a = (String x) {};
  (a as Function(int))(3);
}
''');
  }

  test_function2() async {
    await assertNoErrorsInCode(r'''
class A {}

class B<T extends A> {
  void foo() {
    T Function(T) f;
    f as A Function(A);
  }
}
''');
  }

  test_type_dynamic() async {
    await assertNoErrorsInCode(r'''
void f() {
  Object as dynamic;
}
''');
  }

  test_type_supertype() async {
    await assertErrorsInCode(r'''
void f(int a) {
  a as Object;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 18, 11),
    ]);
  }

  test_type_type() async {
    await assertErrorsInCode(r'''
void f(num a) {
  a as num;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 18, 8),
    ]);
  }

  test_typeParameter_hasBound_same() async {
    await assertErrorsInCode(r'''
void f<T extends num>(T a) {
  a as num;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 31, 8),
    ]);
  }

  test_typeParameter_hasBound_subtype() async {
    await assertErrorsInCode(r'''
void f<T extends int>(T a) {
  a as num;
}
''', [
      error(HintCode.UNNECESSARY_CAST, 31, 8),
    ]);
  }

  test_typeParameter_hasBound_unrelated() async {
    await assertNoErrorsInCode(r'''
void f<T extends num>(T a) {
  a as String;
}
''');
  }

  test_typeParameter_noBound() async {
    await assertNoErrorsInCode(r'''
void f<T>(T a) {
  a as num;
}
''');
  }
}