#2976. Add equality tests. Part 1. (#3021)

Add equality tests. Part 1

LanguageFeatures/Static-access-shorthand/equality_A01_t01.dart

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+// Copyright (c) 2024, 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.
+
+/// @assertion If an expression has the form `e1 == e2` or `e1 != e2`, or a
+/// pattern has the form `== e2` or `!= e2`, where the static type of `e1`, or
+/// the matched value type of the pattern, is S1, and e2 is precisely a
+/// `<staticMemberShorthand>` expression, then assign the type S1 as the
+/// shorthand context of the `<staticMemberShorthandHead>` of e2 before
+/// inferring its static type the same way as above.
+///
+/// @description Checks that if an expression has the form `e1 == e2` or
+/// `e1 != e2` and `e2` is a shorthand expression then it has shorthand
+/// context from `e1`. Test a class.
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=enum-shorthands
+
+import '../../Utils/expect.dart';
+
+class C<T> {
+  String log = "";
+  T value;
+  C(this.value);
+  C.id(this.value);
+  factory C.f(T t) = C;
+
+  static C<int> get staticGetter => C(1);
+  static C<X> staticMethod<X>(X x) => C<X>(x);
+  static List<C<String>> instances = [C("one")];
+
+  @override
+  bool operator ==(Object other) {
+    log = "$this == $other";
+    if (other is C) {
+      return value == other.value;
+    }
+    return false;
+  }
+
+  @override
+  String toString() => "C<$T>($value)";
+}
+
+main() {
+  C<int> c1 = C(1);
+  Expect.isTrue(c1 == .staticGetter);
+  Expect.equals("C<int>(1) == C<int>(1)", c1.log);
+  Expect.isFalse(c1 != .staticGetter);
+  Expect.equals("C<int>(1) == C<int>(1)", c1.log);
+
+  C<int> c2 = C(2);
+  Expect.isFalse(c2 == .staticMethod<String>("two"));
+  Expect.equals("C<int>(2) == C<String>(two)", c2.log);
+  Expect.isTrue(c2 != .staticMethod<String>("two"));
+  Expect.equals("C<int>(2) == C<String>(two)", c2.log);
+
+  C<String> c3 = C("one");
+  Expect.isTrue(c3 == .instances[0]);
+  Expect.equals("C<String>(one) == C<String>(one)", c3.log);
+  Expect.isFalse(c3 != .instances[0]);
+  Expect.equals("C<String>(one) == C<String>(one)", c3.log);
+
+  C<int> c4 = C(4);
+  Expect.isTrue(c4 == .new(4));
+  Expect.equals("C<int>(4) == C<int>(4)", c4.log);
+  Expect.isFalse(c4 != .new(4));
+  Expect.equals("C<int>(4) == C<int>(4)", c4.log);
+
+  C<int> c5 = C(5);
+  Expect.isTrue(c5 == .id(5));
+  Expect.equals("C<int>(5) == C<int>(5)", c5.log);
+  Expect.isFalse(c5 != .id(5));
+  Expect.equals("C<int>(5) == C<int>(5)", c5.log);
+
+  C<int> c6 = C(6);
+  Expect.isTrue(c6 == .f(6));
+  Expect.equals("C<int>(6) == C<int>(6)", c6.log);
+  Expect.isFalse(c6 != .f(6));
+  Expect.equals("C<int>(6) == C<int>(6)", c6.log);
+}

LanguageFeatures/Static-access-shorthand/equality_A01_t02.dart

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+// Copyright (c) 2024, 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.
+
+/// @assertion If an expression has the form `e1 == e2` or `e1 != e2`, or a
+/// pattern has the form `== e2` or `!= e2`, where the static type of `e1`, or
+/// the matched value type of the pattern, is S1, and e2 is precisely a
+/// `<staticMemberShorthand>` expression, then assign the type S1 as the
+/// shorthand context of the `<staticMemberShorthandHead>` of e2 before
+/// inferring its static type the same way as above.
+///
+/// @description Checks that if an expression has the form `e1 == e2` or
+/// `e1 != e2` and `e2` is a shorthand expression then it has shorthand
+/// context from `e1`. Test a mixin.
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=enum-shorthands
+
+import '../../Utils/expect.dart';
+
+class C<T> {
+  String log = "";
+  T value;
+  C(this.value);
+
+  @override
+  bool operator ==(Object other) {
+    log = "$this == $other";
+    if (other is C) {
+      return value == other.value;
+    }
+    return false;
+  }
+
+  @override
+  String toString() => "${this.runtimeType}($value)";
+}
+
+mixin M<T> on C<T> {
+  static M<int> get staticGetter => MC(1);
+  static M<X> staticMethod<X>(X x) => MC<X>(x);
+  static List<M<String>> instances = [MC("one")];
+}
+
+class MC<T> = C<T> with M<T>;
+
+main() {
+  M<int> m1 = MC(1);
+  Expect.isTrue(m1 == .staticGetter);
+  Expect.equals("MC<int>(1) == MC<int>(1)", m1.log);
+  Expect.isFalse(m1 != .staticGetter);
+  Expect.equals("MC<int>(1) == MC<int>(1)", m1.log);
+
+  M<int> m2 = MC(2);
+  Expect.isFalse(m2 == .staticMethod<String>("two"));
+  Expect.equals("MC<int>(2) == MC<String>(two)", m2.log);
+  Expect.isTrue(m2 != .staticMethod<String>("two"));
+  Expect.equals("MC<int>(2) == MC<String>(two)", m2.log);
+
+  MC<String> m3 = MC("one");
+  Expect.isTrue(m3 == .instances[0]);
+  Expect.equals("MC<String>(one) == MC<String>(one)", m3.log);
+  Expect.isFalse(m3 != .instances[0]);
+  Expect.equals("MC<String>(one) == MC<String>(one)", m3.log);
+}

LanguageFeatures/Static-access-shorthand/equality_A01_t03.dart

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+// Copyright (c) 2024, 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.
+
+/// @assertion If an expression has the form `e1 == e2` or `e1 != e2`, or a
+/// pattern has the form `== e2` or `!= e2`, where the static type of `e1`, or
+/// the matched value type of the pattern, is S1, and e2 is precisely a
+/// `<staticMemberShorthand>` expression, then assign the type S1 as the
+/// shorthand context of the `<staticMemberShorthandHead>` of e2 before
+/// inferring its static type the same way as above.
+///
+/// @description Checks that if an expression has the form `e1 == e2` or
+/// `e1 != e2` and `e2` is a shorthand expression then it has shorthand
+/// context from `e1`. Test an enum.
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=enum-shorthands
+
+import '../../Utils/expect.dart';
+
+enum E<T> {
+  e0(0), e1("1");
+  final T value;
+  const E(this.value);
+
+  static E<int> get staticGetter => E.e0;
+  static E staticMethod(int index) => E.values[index];
+}
+
+main() {
+  Expect.isTrue(E.e0 == .e0);
+  Expect.isFalse(E.e0 != .e1);
+
+  Expect.isTrue(E.e0 == .staticGetter);
+  Expect.isFalse(E.e0 != .staticGetter);
+
+  Expect.isFalse(E.e1 == .staticMethod(0));
+  Expect.isTrue(E.e1 != .staticMethod(0));
+
+  Expect.isTrue(E.e0 == .values[0]);
+  Expect.isFalse(E.e0 != .values[0]);
+}

LanguageFeatures/Static-access-shorthand/equality_A01_t04.dart

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+// Copyright (c) 2024, 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.
+
+/// @assertion If an expression has the form `e1 == e2` or `e1 != e2`, or a
+/// pattern has the form `== e2` or `!= e2`, where the static type of `e1`, or
+/// the matched value type of the pattern, is S1, and e2 is precisely a
+/// `<staticMemberShorthand>` expression, then assign the type S1 as the
+/// shorthand context of the `<staticMemberShorthandHead>` of e2 before
+/// inferring its static type the same way as above.
+///
+/// @description Checks that if an expression has the form `e1 == e2` or
+/// `e1 != e2` and `e2` is a shorthand expression then it has shorthand
+/// context from `e1`. Test an extension type.
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=enum-shorthands
+
+import '../../Utils/expect.dart';
+
+extension type ET<T>(T value) {
+  ET.id(this.value);
+  factory ET.f(T t) = ET;
+
+  static ET<int> get staticGetter => ET(1);
+  static ET<X> staticMethod<X>(X x) => ET<X>(x);
+  static List<ET<String>> instances = [ET("one")];
+}
+
+main() {
+  Expect.isTrue(ET(1) == .staticGetter);
+  Expect.isFalse(ET(1) != .staticGetter);
+
+  Expect.isFalse(ET<int>(2) == .staticMethod<String>("two"));
+  Expect.isTrue(ET<int>(2) != .staticMethod<String>("two"));
+
+  Expect.isTrue(ET<String>("one") == .instances[0]);
+  Expect.isFalse(ET<String>("one") != .instances[0]);
+
+  Expect.isTrue(ET(4) == .new(4));
+  Expect.isFalse(ET(4) != .new(4));
+
+  Expect.isTrue(ET(5) == .id(5));
+  Expect.isFalse(ET(5) != .id(5));
+
+  Expect.isTrue(ET(6) == .f(6));
+  Expect.isFalse(ET(6) != .f(6));
+}

LanguageFeatures/Static-access-shorthand/equality_A01_t05.dart

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+// Copyright (c) 2024, 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.
+
+/// @assertion If an expression has the form `e1 == e2` or `e1 != e2`, or a
+/// pattern has the form `== e2` or `!= e2`, where the static type of `e1`, or
+/// the matched value type of the pattern, is S1, and e2 is precisely a
+/// `<staticMemberShorthand>` expression, then assign the type S1 as the
+/// shorthand context of the `<staticMemberShorthandHead>` of e2 before
+/// inferring its static type the same way as above.
+///
+/// @description Checks that if a pattern has the form `== e2` or `!= e2` and
+/// `e2` is a shorthand expression, then it has context type from the matched
+/// value type of the pattern. Test a class.
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=enum-shorthands
+
+import '../../Utils/expect.dart';
+
+class C<T> {
+  final T value;
+  const C(this.value);
+  const C.id(this.value);
+  const factory C.f(T t) = C;
+
+  static const C<int> intOne = C(1);
+
+  @override
+  bool operator ==(Object other) {
+    if (other is C) {
+      return value == other.value;
+    }
+    return false;
+  }
+}
+
+main() {
+  bool success = false;
+  void checkSuccess() {
+    Expect.isTrue(success);
+    success = false;
+  }
+
+  C<int> c1 = C(1);
+  if (c1 case == const .new(1)) {
+    success = true;
+  }
+  checkSuccess();
+
+  if (c1 case == const .id(1)) {
+    success = true;
+  }
+  checkSuccess();
+
+  if (c1 case == const .f(1)) {
+    success = true;
+  }
+  checkSuccess();
+
+  if (c1 case == .intOne) {
+    success = true;
+  }
+  checkSuccess();
+
+  C<int> c2 = C(2);
+  if (c2 case != const .new(1)) {
+    success = true;
+  }
+  checkSuccess();
+
+  if (c2 case != const .id(1)) {
+    success = true;
+  }
+  checkSuccess();
+
+  if (c2 case != const .f(1)) {
+    success = true;
+  }
+  checkSuccess();
+
+  if (c2 case != .intOne) {
+    success = true;
+  }
+  checkSuccess();
+}

LanguageFeatures/Static-access-shorthand/equality_A01_t06.dart

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+// Copyright (c) 2024, 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.
+
+/// @assertion If an expression has the form `e1 == e2` or `e1 != e2`, or a
+/// pattern has the form `== e2` or `!= e2`, where the static type of `e1`, or
+/// the matched value type of the pattern, is S1, and e2 is precisely a
+/// `<staticMemberShorthand>` expression, then assign the type S1 as the
+/// shorthand context of the `<staticMemberShorthandHead>` of e2 before
+/// inferring its static type the same way as above.
+///
+/// @description Checks that if a pattern has the form `== e2` or `!= e2` and
+/// `e2` is a shorthand expression, then it has context type from the matched
+/// value type of the pattern. Test a mixin.
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=enum-shorthands
+
+import '../../Utils/expect.dart';
+
+class C<T> {
+  final T value;
+  const C(this.value);
+
+  @override
+  bool operator ==(Object other) {
+    if (other is C) {
+      return value == other.value;
+    }
+    return false;
+  }
+}
+
+mixin M<T> on C<T> {
+  static const M<int> intOne = MC<int>(1);
+}
+
+class MC<T> extends C<T> with M<T> {
+  const MC(T t) : super(t);
+}
+
+main() {
+  bool success = false;
+  M<int> m = MC(1);
+  if (m case == .intOne) {
+    success = true;
+  }
+  Expect.isTrue(success);
+
+  success = false;
+  if (m case != .intOne) {
+    success = true;
+  }
+  Expect.isFalse(success);
+}