pkg/linter/test/rules/void_checks_test.dart

// Copyright (c) 2021, 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:test_reflective_loader/test_reflective_loader.dart';

import '../rule_test_support.dart';

void main() {
  defineReflectiveSuite(() {
    defineReflectiveTests(VoidChecksTest);
  });
}

@reflectiveTest
class VoidChecksTest extends LintRuleTest {
  @override
  String get lintRule => LintNames.void_checks;

  test_assert_blockBody_returnStatement() async {
    await assertNoDiagnostics(r'''
void f() {
  assert(() {
    return true;
  }());
}
''');
  }

  test_constructorArgument_genericParameter() async {
    await assertDiagnostics(
      r'''
void f(dynamic p) {
  A<void>.c(p);
}
class A<T> {
  T value;
  A.c(this.value);
}
''',
      [lint(32, 1)],
    );
  }

  test_emptyFunctionExpressionReturningFutureOrVoid() async {
    await assertNoDiagnostics(r'''
import 'dart:async';

void emptyFunctionExpressionReturningFutureOrVoid(FutureOr<void> Function() f) {
  f = () {};
}
''');
  }

  test_extraPositionalArgument() async {
    await assertDiagnostics(
      r'''
missing_parameter_for_argument() {
  void foo() {}
  foo(0);
}
''',
      [
        // No lint
        error(CompileTimeErrorCode.extraPositionalArguments, 57, 1),
      ],
    );
  }

  test_functionArgument_FutureOrVoidParameter_dynamicArgument() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f(dynamic p) {
  m(p);
}
void m(FutureOr<void> arg) {}
''');
  }

  test_functionArgument_FutureOrVoidParameter_FutureOrVoidArgument() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f(FutureOr<void> p) {
  m(p);
}
void m(FutureOr<void> arg) {}
''');
  }

  test_functionArgument_FutureOrVoidParameter_FutureVoidArgument() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f(Future<void> p) {
  m(p);
}
void m(FutureOr<void> arg) {}
''');
  }

  test_functionArgument_FutureOrVoidParameter_nullArgument() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f() {
  m(null);
}
void m(FutureOr<void> arg) {}
''');
  }

  test_functionArgument_voidParameter_dynamicArgument() async {
    await assertDiagnostics(
      r'''
void f(dynamic p) {
  m(p);
}
void m(void arg) {}
''',
      [lint(24, 1)],
    );
  }

  test_functionArgument_voidParameter_named() async {
    await assertDiagnostics(
      r'''
void f(dynamic p) {
  m(p: p);
}
void m({required void p}) {}
''',
      [lint(27, 1)],
    );
  }

  test_functionArgument_voidParameter_optional() async {
    await assertDiagnostics(
      r'''
void f(dynamic p) {
  m(p);
}
void m([void v]) {}
''',
      [lint(24, 1)],
    );
  }

  test_functionExpression_blockBody_returnStatement_genericContext() async {
    await assertNoDiagnostics(r'''
generics_with_function() {
  g<T>(T Function() p) => p();
  g(() {
    return 1;
  });
}
''');
  }

  test_functionExpression_blockBody_returnStatement_voidContext() async {
    await assertNoDiagnostics(r'''
void f() {
  void g(Function p) {}
  g(() async {
    return 1;
  });
}
''');
  }

  // https://github.com/dart-lang/linter/issues/2685
  test_functionType_FutureOrVoidReturnType_Never() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f() {
  foo(() {
    fail(); // OK
  });
}

void foo(FutureOr<void> Function() p) {}
Never fail() { throw ''; }
''');
  }

  /// https://github.com/dart-lang/linter/issues/4019
  test_future_dynamic() async {
    await assertNoDiagnostics(r'''
import 'dart:async';

void f(FutureOr<void>? arg) {
  Future<dynamic>? future;
  f(future);
}
''');
  }

  /// https://github.com/dart-lang/linter/issues/3172
  test_futureOrCallback() async {
    await assertNoDiagnostics(r'''
import 'dart:async';

void capture(FutureOr<void> Function() callback) {}

void f() {
  capture(() {
    throw "oh no";
  });
}
''');
  }

  test_futureOrVoidField_assignDynamic() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f(A a, dynamic p) {
  a.x = p; // OK
}
class A {
  FutureOr<void> x;
  A(this.x);
}
''');
  }

  test_futureOrVoidField_assignFutureOrVoid() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f(A a, FutureOr<void> p) {
  a.x = p;
}
class A {
  FutureOr<void> x;
  A(this.x);
}
''');
  }

  test_futureOrVoidField_assignFutureVoid() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f(A a) {
  a.x = Future.value();
}
class A {
  FutureOr<void> x;
  A(this.x);
}
''');
  }

  test_futureOrVoidField_assignInt() async {
    await assertDiagnostics(
      r'''
import 'dart:async';
void f(A a) {
  a.x = 1;
}
class A {
  FutureOr<void> x;
  A(this.x);
}
''',
      [lint(37, 7)],
    );
  }

  test_futureOrVoidField_assignNull() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f(A a) {
  a.x = null; // OK
}
class A {
  FutureOr<void> x;
  A(this.x);
}
''');
  }

  test_futureOrVoidFunction_blockBody_returnsFuture() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
FutureOr<void> f() {
  return Future.value();
}
''');
  }

  test_futureOrVoidFunction_blockBody_returnStatement() async {
    await assertDiagnostics(
      r'''
import 'dart:async';
FutureOr<void> f() {
  return 1;
}
''',
      [lint(44, 9)],
    );
  }

  test_listPattern_local() async {
    await assertDiagnostics(
      r'''
void f() {
  void p;
  [p] = <int>[7];
  return p;
}
''',
      [lint(24, 1)],
    );
  }

  test_listPattern_param() async {
    await assertDiagnostics(
      r'''
void f(void p) {
  [p] = <int>[7];
}
''',
      [lint(20, 1)],
    );
  }

  test_localFunction_emptyBlockBody_matchingFutureOrVoidSignature() async {
    await assertNoDiagnostics(r'''
import 'dart:async';
void f(FutureOr<void> Function() p) {
  p = () {};
}
''');
  }

  test_neverReturningCallbackThrows() async {
    await assertNoDiagnostics(r'''
import 'dart:async';

Never fail() { throw ''; }

void f() async {
  await Future.value(5).then<void>((x) {
    fail();
  });
}
''');
  }

  test_nonVoidFunction_assignedToVoidFunction() async {
    await assertNoDiagnostics(r'''
void f(void Function() p) {
  int g() => 1;
  p = g;
}
''');
  }

  test_recordPattern() async {
    await assertDiagnostics(
      r'''
void f(void p) {
  (p, ) = (7, );
}
''',
      [lint(20, 1)],
    );
  }

  test_returnOfInvalidType() async {
    await assertDiagnostics(
      r'''
void bug2813() {
  return 1;
}
''',
      [
        // No lint
        error(CompileTimeErrorCode.returnOfInvalidTypeFromFunction, 26, 1),
      ],
    );
  }

  // https://github.com/dart-lang/linter/issues/2685
  test_returnTypeVoid_Never() async {
    await assertNoDiagnostics(r'''
void f(Future<int> p) {
  p.then<void>((_) {
    fail();
  });
}

Never fail() { throw ''; }
''');
  }

  test_returnTypeVoid_throw() async {
    await assertNoDiagnostics(r'''
void f(Future<int> p) {
  p.then<void>((_) {
    throw '';
  });
}
''');
  }

  test_setterArgument_genericParameter() async {
    await assertDiagnostics(
      r'''
void f(A<void> a, dynamic p) {
  a.f = p;
}
class A<T> {
  set f(T value) {}
}
''',
      [lint(33, 7)],
    );
  }

  test_voidFunction_blockBody_returnStatement() async {
    await assertDiagnostics(
      r'''
void f(dynamic p) {
  return p;
}
''',
      [lint(22, 9)],
    );
  }

  test_voidFunction_blockBody_returnStatement_empty() async {
    await assertNoDiagnostics(r'''
void f() {
  return;
}
''');
  }

  test_voidFunction_expressionBody() async {
    await assertNoDiagnostics(r'''
void f() => 7;
''');
  }
}