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

// Copyright (c) 2020, 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/diagnostic/diagnostic.dart' as diag;
import 'package:test/test.dart';
import 'package:test_reflective_loader/test_reflective_loader.dart';

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

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

@reflectiveTest
class ReadWriteTest extends PubPackageResolutionTest {
  @override
  bool get retainDataForTesting => true;

  test_final_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
// @dart = 3.10
void f(final x) {
  x;
}
''');
    _assertAssigned('x;', assigned: true, unassigned: false);
  }

  test_final_definitelyAssigned_read_prefixNegate() async {
    await assertNoErrorsInCode(r'''
// @dart = 3.10
void f(final x) {
  -x;
}
''');
    _assertAssigned('x;', assigned: true, unassigned: false);
  }

  test_final_definitelyAssigned_readWrite_compoundAssignment() async {
    await assertErrorsInCode(
      r'''
// @dart = 3.10
void f(final x) {
  x += 1;
}
''',
      [error(diag.assignmentToFinalLocal, 36, 1)],
    );
    _assertAssigned('x +=', assigned: true, unassigned: false);
  }

  test_final_definitelyAssigned_readWrite_postfixIncrement() async {
    await assertErrorsInCode(
      r'''
// @dart = 3.10
void f(final x) {
  x++;
}
''',
      [error(diag.assignmentToFinalLocal, 36, 1)],
    );
    _assertAssigned('x++', assigned: true, unassigned: false);
  }

  test_final_definitelyAssigned_readWrite_prefixIncrement() async {
    await assertErrorsInCode(
      r'''
// @dart = 3.10
void f(final x) {
  ++x;
}
''',
      [error(diag.assignmentToFinalLocal, 38, 1)],
    );
    _assertAssigned('x;', assigned: true, unassigned: false);
  }

  test_final_definitelyAssigned_write() async {
    await assertErrorsInCode(
      r'''
// @dart = 3.10
void f(final x) {
  x = 0;
}
''',
      [error(diag.assignmentToFinalLocal, 36, 1)],
    );
    _assertAssigned('x =', assigned: true, unassigned: false);
  }

  test_final_definitelyAssigned_write_forEachLoop_identifier() async {
    await assertErrorsInCode(
      r'''
// @dart = 3.10
void f(final x) {
  for (x in [0, 1, 2]) {
    x;
  }
}
''',
      [error(diag.assignmentToFinalLocal, 41, 1)],
    );
    _assertAssigned('x in', assigned: true, unassigned: false);
  }

  test_final_definitelyUnassigned_read() async {
    await assertErrorsInCode(
      r'''
void f() {
  final x;
  x; // 0
  x();
}
''',
      [
        error(diag.readPotentiallyUnassignedFinal, 24, 1),
        error(diag.readPotentiallyUnassignedFinal, 34, 1),
      ],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
    _assertAssigned('x()', assigned: false, unassigned: true);
  }

  test_final_definitelyUnassigned_readWrite_compoundAssignment() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  final x;
  x += 1;
}
''',
      [error(diag.readPotentiallyUnassignedFinal, 58, 1)],
    );
    _assertAssigned('x +=', assigned: false, unassigned: true);
  }

  test_final_definitelyUnassigned_readWrite_postfixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  final x;
  x++;
}
''',
      [error(diag.readPotentiallyUnassignedFinal, 58, 1)],
    );
    _assertAssigned('x++', assigned: false, unassigned: true);
  }

  test_final_definitelyUnassigned_readWrite_prefixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  final x;
  ++x; // 0
}
''',
      [error(diag.readPotentiallyUnassignedFinal, 60, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_final_definitelyUnassigned_write() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  final x;
  x = 0;
}
''');
    _assertAssigned('x = 0', assigned: false, unassigned: true);
  }

  test_final_neither_read() async {
    await assertErrorsInCode(
      r'''
void f(bool b) {
  final x;
  if (b) x = 0;
  x; // 0
}
''',
      [error(diag.readPotentiallyUnassignedFinal, 46, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_final_neither_readWrite_compoundAssignment() async {
    await assertErrorsInCode(
      r'''
void f(bool b) {
  // ignore:unused_local_variable
  final x;
  if (b) x = 0;
  x += 1;
}
''',
      [
        error(diag.assignmentToFinalLocal, 80, 1),
        error(diag.readPotentiallyUnassignedFinal, 80, 1),
      ],
    );
    _assertAssigned('x +=', assigned: false, unassigned: false);
  }

  test_final_neither_readWrite_postfixIncrement() async {
    await assertErrorsInCode(
      r'''
void f(bool b) {
  // ignore:unused_local_variable
  final x;
  if (b) x = 0;
  x++;
}
''',
      [
        error(diag.assignmentToFinalLocal, 80, 1),
        error(diag.readPotentiallyUnassignedFinal, 80, 1),
      ],
    );
    _assertAssigned('x++', assigned: false, unassigned: false);
  }

  test_final_neither_readWrite_prefixIncrement() async {
    await assertErrorsInCode(
      r'''
void f(bool b) {
  // ignore:unused_local_variable
  final x;
  if (b) x = 0;
  ++x; // 0
}
''',
      [
        error(diag.assignmentToFinalLocal, 82, 1),
        error(diag.readPotentiallyUnassignedFinal, 82, 1),
      ],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_final_neither_write() async {
    await assertErrorsInCode(
      r'''
void f(bool b) {
  // ignore:unused_local_variable
  final x;
  if (b) x = 0;
  x = 1;
}
''',
      [error(diag.assignmentToFinalLocal, 80, 1)],
    );
    _assertAssigned('x = 1', assigned: false, unassigned: false);
  }

  test_lateFinal_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f() {
  late final x;
  x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_lateFinal_definitelyAssigned_readWrite_compoundAssignment() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final x;
  x = 0;
  x += 1;
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 72, 1)],
    );
    _assertAssigned('x +=', assigned: true, unassigned: false);
  }

  test_lateFinal_definitelyAssigned_readWrite_postfixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final x;
  x = 0;
  x++;
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 72, 1)],
    );
    _assertAssigned('x++', assigned: true, unassigned: false);
  }

  test_lateFinal_definitelyAssigned_readWrite_prefixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final x;
  x = 0;
  ++x; // 0
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 74, 1)],
    );
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_lateFinal_definitelyAssigned_write() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final x;
  x = 0;
  x = 1;
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 72, 1)],
    );
    _assertAssigned('x = 1', assigned: true, unassigned: false);
  }

  test_lateFinal_definitelyUnassigned_read() async {
    await assertErrorsInCode(
      r'''
void f() {
  late final x;
  x; // 0
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 29, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_lateFinal_definitelyUnassigned_readWrite_compoundAssignment() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final x;
  x += 1;
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 63, 1)],
    );
    _assertAssigned('x +=', assigned: false, unassigned: true);
  }

  test_lateFinal_definitelyUnassigned_readWrite_postfixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final x;
  x++;
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 63, 1)],
    );
    _assertAssigned('x++', assigned: false, unassigned: true);
  }

  test_lateFinal_definitelyUnassigned_readWrite_prefixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final x;
  ++x; // 0
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 65, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_lateFinal_definitelyUnassigned_write() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  late final x;
  x = 0;
}
''');
    _assertAssigned('x =', assigned: false, unassigned: true);
  }

  test_lateFinal_neither_read() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  late final x;
  if (b) x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_lateFinal_neither_readWrite_compoundAssignment() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late final x;
  if (b) x = 0;
  x += 1;
}
''');
    _assertAssigned('x +=', assigned: false, unassigned: false);
  }

  test_lateFinal_neither_readWrite_postfixIncrement() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late final x;
  if (b) x = 0;
  x++;
}
''');
    _assertAssigned('x++', assigned: false, unassigned: false);
  }

  test_lateFinal_neither_readWrite_prefixIncrement() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late final x;
  if (b) x = 0;
  ++x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_lateFinal_neither_write() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late final x;
  if (b) x = 0;
  x = 1;
}
''');
    _assertAssigned('x = 1', assigned: false, unassigned: false);
  }

  test_lateFinalNullable_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f() {
  late final int? x;
  x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_lateFinalNullable_definitelyAssigned_readWrite_compoundAssignment() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final int? x;
  x = 0;
  x += 1;
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 77, 1)],
    );
    _assertAssigned('x +=', assigned: true, unassigned: false);
  }

  test_lateFinalNullable_definitelyAssigned_readWrite_postfixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final int? x;
  x = 0;
  x++;
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 77, 1)],
    );
    _assertAssigned('x++', assigned: true, unassigned: false);
  }

  test_lateFinalNullable_definitelyAssigned_readWrite_prefixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final int? x;
  x = 0;
  ++x; // 0
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 79, 1)],
    );
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_lateFinalNullable_definitelyAssigned_write() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final int? x;
  x = 0;
  x = 1;
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 77, 1)],
    );
    _assertAssigned('x = 1', assigned: true, unassigned: false);
  }

  test_lateFinalNullable_definitelyUnassigned_read() async {
    await assertErrorsInCode(
      r'''
void f() {
  late final int? x;
  x; // 0
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 34, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_lateFinalNullable_definitelyUnassigned_readWrite_compoundAssignment() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final int? x;
  x += 1;
}
''',
      [
        error(diag.definitelyUnassignedLateLocalVariable, 68, 1),
        error(diag.uncheckedMethodInvocationOfNullableValue, 70, 2),
      ],
    );
    _assertAssigned('x +=', assigned: false, unassigned: true);
  }

  test_lateFinalNullable_definitelyUnassigned_readWrite_postfixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final int? x;
  x++;
}
''',
      [
        error(diag.definitelyUnassignedLateLocalVariable, 68, 1),
        error(diag.uncheckedMethodInvocationOfNullableValue, 69, 2),
      ],
    );
    _assertAssigned('x++', assigned: false, unassigned: true);
  }

  test_lateFinalNullable_definitelyUnassigned_readWrite_prefixIncrement() async {
    await assertErrorsInCode(
      r'''
void f() {
  // ignore:unused_local_variable
  late final int? x;
  ++x; // 0
}
''',
      [
        error(diag.definitelyUnassignedLateLocalVariable, 70, 1),
        error(diag.uncheckedMethodInvocationOfNullableValue, 68, 2),
      ],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_lateFinalNullable_definitelyUnassigned_write() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  late final int? x;
  x = 0;
}
''');
    _assertAssigned('x = 0', assigned: false, unassigned: true);
  }

  test_lateFinalNullable_neither_read() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  late final int? x;
  if (b) x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_lateFinalNullable_neither_readWrite_compoundAssignment() async {
    await assertErrorsInCode(
      r'''
void f(bool b) {
  // ignore:unused_local_variable
  late final int? x;
  if (b) x = 0;
  x += 1;
}
''',
      [error(diag.uncheckedMethodInvocationOfNullableValue, 92, 2)],
    );
    _assertAssigned('x +=', assigned: false, unassigned: false);
  }

  test_lateFinalNullable_neither_readWrite_postfixIncrement() async {
    await assertErrorsInCode(
      r'''
void f(bool b) {
  // ignore:unused_local_variable
  late final int? x;
  if (b) x = 0;
  x++;
}
''',
      [error(diag.uncheckedMethodInvocationOfNullableValue, 91, 2)],
    );
    _assertAssigned('x++', assigned: false, unassigned: false);
  }

  test_lateFinalNullable_neither_readWrite_prefixIncrement() async {
    await assertErrorsInCode(
      r'''
void f(bool b) {
  // ignore:unused_local_variable
  late final int? x;
  if (b) x = 0;
  ++x; // 0
}
''',
      [error(diag.uncheckedMethodInvocationOfNullableValue, 90, 2)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_lateFinalNullable_neither_write() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late final int? x;
  if (b) x = 0;
  x = 1;
}
''');
    _assertAssigned('x = 1', assigned: false, unassigned: false);
  }

  test_lateFinalPotentiallyNonNullable_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f<T>(T t) {
  late final T x;
  x = t;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_lateFinalPotentiallyNonNullable_definitelyAssigned_write() async {
    await assertErrorsInCode(
      r'''
void f<T>(T t, T t2) {
  // ignore:unused_local_variable
  late final T x;
  x = t;
  x = t2;
}
''',
      [error(diag.lateFinalLocalAlreadyAssigned, 86, 1)],
    );
    _assertAssigned('x = t2', assigned: true, unassigned: false);
  }

  test_lateFinalPotentiallyNonNullable_definitelyUnassigned_read() async {
    await assertErrorsInCode(
      r'''
void f<T>() {
  late final T x;
  x; // 0
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 34, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_lateFinalPotentiallyNonNullable_definitelyUnassigned_write() async {
    await assertNoErrorsInCode(r'''
void f<T>(T t) {
  // ignore:unused_local_variable
  late final T x;
  x = t;
}
''');
    _assertAssigned('x = t', assigned: false, unassigned: true);
  }

  test_lateFinalPotentiallyNonNullable_neither_read() async {
    await assertNoErrorsInCode(r'''
void f<T>(bool b, T t) {
  late final T x;
  if (b) x = t;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_lateFinalPotentiallyNonNullable_neither_write() async {
    await assertNoErrorsInCode(r'''
void f<T>(bool b, T t, T t2) {
  // ignore:unused_local_variable
  late final T x;
  if (b) x = t;
  x = t2;
}
''');
    _assertAssigned('x = t2', assigned: false, unassigned: false);
  }

  test_lateNullable_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f() {
  late int? x;
  x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_lateNullable_definitelyUnassigned_read() async {
    await assertErrorsInCode(
      r'''
void f() {
  late int? x;
  x; // 0
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 28, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_lateNullable_neither_read() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  late int? x;
  if (b) x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_latePotentiallyNonNullable_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f<T>(T t) {
  late T x;
  x = t;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_latePotentiallyNonNullable_definitelyUnassigned_read() async {
    await assertErrorsInCode(
      r'''
void f<T>() {
  late T x;
  x; // 0
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 28, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_latePotentiallyNonNullable_neither_read() async {
    await assertNoErrorsInCode(r'''
void f<T>(bool b, T t) {
  late T x;
  if (b) x = t;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_lateVar_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f() {
  late var x;
  x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_lateVar_definitelyAssigned_readWrite_compoundAssignment() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  late var x;
  x = 0;
  x += 1;
}
''');
    _assertAssigned('x +=', assigned: true, unassigned: false);
  }

  test_lateVar_definitelyAssigned_readWrite_postfixIncrement() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  late var x;
  x = 0;
  x++;
}
''');
    _assertAssigned('x++', assigned: true, unassigned: false);
  }

  test_lateVar_definitelyAssigned_readWrite_prefixIncrement() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  late var x;
  x = 0;
  ++x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_lateVar_definitelyAssigned_write() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  late var x;
  x = 0;
  x = 1;
}
''');
    _assertAssigned('x = 1', assigned: true, unassigned: false);
  }

  test_lateVar_definitelyUnassigned_read() async {
    await assertErrorsInCode(
      r'''
void f() {
  late var x;
  x; // 0
}
''',
      [error(diag.definitelyUnassignedLateLocalVariable, 27, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_lateVar_neither_read() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  late var x;
  if (b) x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_lateVar_neither_readWrite_compoundAssignment() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late var x;
  if (b) x = 0;
  x += 1;
}
''');
    _assertAssigned('x +=', assigned: false, unassigned: false);
  }

  test_lateVar_neither_readWrite_postfixIncrement() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late var x;
  if (b) x = 0;
  x++;
}
''');
    _assertAssigned('x++', assigned: false, unassigned: false);
  }

  test_lateVar_neither_readWrite_prefixIncrement() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late var x;
  if (b) x = 0;
  ++x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_lateVar_neither_write() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  late var x;
  if (b) x = 0;
  x = 1;
}
''');
    _assertAssigned('x = 1', assigned: false, unassigned: false);
  }

  test_notNullable_write_forEachLoop_identifier() async {
    await assertNoErrorsInCode(r'''
void f() {
  int x;
  for (x in [0, 1, 2]) {
    x; // 0
  }
}
''');
    _assertAssigned('x in', assigned: false, unassigned: true);
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_nullable_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f(int? x) {
  x;
}
''');
    _assertAssigned('x;', assigned: true, unassigned: false);
  }

  test_nullable_definitelyAssigned_write() async {
    await assertNoErrorsInCode(r'''
void f(int? x) {
  x = 0;
}
''');
    _assertAssigned('x = 0', assigned: true, unassigned: false);
  }

  test_nullable_definitelyUnassigned_read() async {
    await assertNoErrorsInCode(r'''
void f() {
  int? x;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_nullable_definitelyUnassigned_write() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  int? x;
  x = 0;
}
''');
    _assertAssigned('x = 0', assigned: false, unassigned: true);
  }

  test_nullable_neither_read() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  int? x;
  if (b) x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_nullable_neither_write() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  int? x;
  if (b) x = 0;
  x = 1;
}
''');
    _assertAssigned('x = 1', assigned: false, unassigned: false);
  }

  test_potentiallyNonNullable_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f<T>(T x) {
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: true, unassigned: false);
  }

  test_potentiallyNonNullable_definitelyAssigned_write() async {
    await assertNoErrorsInCode(r'''
void f<T>(T x, T t) {
  x = t;
}
''');
    _assertAssigned('x = t', assigned: true, unassigned: false);
  }

  test_potentiallyNonNullable_definitelyUnassigned_read() async {
    await assertErrorsInCode(
      r'''
void f<T>() {
  T x;
  x; // 0
}
''',
      [error(diag.notAssignedPotentiallyNonNullableLocalVariable, 23, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_potentiallyNonNullable_definitelyUnassigned_write() async {
    await assertNoErrorsInCode(r'''
void f<T>(T t) {
  // ignore:unused_local_variable
  T x;
  x = t;
}
''');
    _assertAssigned('x = t', assigned: false, unassigned: true);
  }

  test_potentiallyNonNullable_neither_read() async {
    await assertErrorsInCode(
      r'''
void f<T>(bool b, T t) {
  T x;
  if (b) x = t;
  x; // 0
}
''',
      [error(diag.notAssignedPotentiallyNonNullableLocalVariable, 50, 1)],
    );
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_potentiallyNonNullable_neither_write() async {
    await assertNoErrorsInCode(r'''
void f<T>(bool b, T t, T t2) {
  // ignore:unused_local_variable
  T x;
  if (b) x = t;
  x = t2;
}
''');
    _assertAssigned('x = t2', assigned: false, unassigned: false);
  }

  test_var_definitelyAssigned_read() async {
    await assertNoErrorsInCode(r'''
void f(x) {
  x;
}
''');
    _assertAssigned('x;', assigned: true, unassigned: false);
  }

  test_var_definitelyAssigned_readWrite_compoundAssignment() async {
    await assertNoErrorsInCode(r'''
void f(x) {
  x += 1;
}
''');
    _assertAssigned('x +=', assigned: true, unassigned: false);
  }

  test_var_definitelyAssigned_readWrite_postfixIncrement() async {
    await assertNoErrorsInCode(r'''
void f(x) {
  x++;
}
''');
    _assertAssigned('x++', assigned: true, unassigned: false);
  }

  test_var_definitelyAssigned_readWrite_prefixIncrement() async {
    await assertNoErrorsInCode(r'''
void f(x) {
  ++x;
}
''');
    _assertAssigned('x;', assigned: true, unassigned: false);
  }

  test_var_definitelyAssigned_write() async {
    await assertNoErrorsInCode(r'''
void f(x) {
  x = 0;
}
''');
    _assertAssigned('x =', assigned: true, unassigned: false);
  }

  test_var_definitelyUnassigned_read() async {
    await assertNoErrorsInCode(r'''
void f() {
  var x;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_var_definitelyUnassigned_readWrite_compoundAssignment() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  var x;
  x += 0;
}
''');
    _assertAssigned('x +=', assigned: false, unassigned: true);
  }

  test_var_definitelyUnassigned_readWrite_postfixIncrement() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  var x;
  x++;
}
''');
    _assertAssigned('x++', assigned: false, unassigned: true);
  }

  test_var_definitelyUnassigned_readWrite_prefixIncrement() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  var x;
  ++x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: true);
  }

  test_var_definitelyUnassigned_write() async {
    await assertNoErrorsInCode(r'''
void f() {
  // ignore:unused_local_variable
  var x;
  x = 0;
}
''');
    _assertAssigned('x = 0', assigned: false, unassigned: true);
  }

  test_var_neither_read() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  var x;
  if (b) x = 0;
  x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_var_neither_readWrite_compoundAssignment() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  var x;
  if (b) x = 0;
  x += 1;
}
''');
    _assertAssigned('x += 1', assigned: false, unassigned: false);
  }

  test_var_neither_readWrite_postfixIncrement() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  var x;
  if (b) x = 0;
  ++x; // 0
}
''');
    _assertAssigned('x; // 0', assigned: false, unassigned: false);
  }

  test_var_neither_readWrite_prefixIncrement() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  var x;
  if (b) x = 0;
  x++;
}
''');
    _assertAssigned('x++', assigned: false, unassigned: false);
  }

  test_var_neither_write() async {
    await assertNoErrorsInCode(r'''
void f(bool b) {
  // ignore:unused_local_variable
  var x;
  if (b) x = 0;
  x = 1;
}
''');
    _assertAssigned('x = 1', assigned: false, unassigned: false);
  }

  void _assertAssigned(
    String search, {
    required bool assigned,
    required bool unassigned,
  }) {
    var node = findNode.simple(search);

    var testingData = driverFor(testFile).testingData!;
    var unitData = testingData.uriToFlowAnalysisData[result.uri]!;

    if (assigned) {
      expect(unitData.definitelyAssigned, contains(node));
    } else {
      expect(unitData.notDefinitelyAssigned, contains(node));
      expect(unitData.definitelyAssigned, isNot(contains(node)));
    }

    if (unassigned) {
      expect(unitData.definitelyUnassigned, contains(node));
    } else {
      expect(unitData.definitelyUnassigned, isNot(contains(node)));
    }
  }
}