#2420. Add null-check-pattern tests for extension types (#2475)

LanguageFeatures/Extension-types/exhaustiveness_null_check_A01_t01.dart

@@ -0,0 +1,114 @@
+// 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 The lifted space union for a pattern with matched value type M is
+/// ...
+/// Null-check pattern:
+/// i. Let S be the expanded spaces of the lifted space union of the subpattern.
+/// ii. Remove any unions in S that have type Null. A null-check pattern
+///   specifically does not match null, so even if the subpattern would handle
+///   it, it will never see it.
+/// iii. The result is S.
+///
+/// @description Check that a null-check pattern removes any unions in `S` that
+/// have type `Null`. Test switch statement
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+extension type const BoolET1(bool _) {}
+extension type const BoolET2(bool _) implements bool {}
+extension type const ObjectET1(Object _) {}
+extension type const ObjectET2(Object _) implements Object {}
+
+String test1(BoolET1? o) {
+  switch (o) {
+//^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    case Object? _?:
+      return "not exhaustive";
+  }
+}
+
+String test2(BoolET2? o) {
+  switch (o) {
+//^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    case Object? _?:
+      return "not exhaustive";
+  }
+}
+
+String test3(BoolET1? o) {
+  switch (o) {
+//^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    case ObjectET1? _?:
+      return "not exhaustive";
+  }
+}
+
+String test4(BoolET1? o) {
+  switch (o) {
+//^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    case ObjectET2? _?:
+      return "not exhaustive";
+  }
+}
+
+String test5(BoolET2? o) {
+  switch (o) {
+//^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    case ObjectET1? _?:
+      return "not exhaustive";
+  }
+}
+
+String test6(BoolET2? o) {
+  switch (o) {
+//^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    case ObjectET2? _?:
+      return "not exhaustive";
+  }
+}
+
+String test7(bool? o) {
+  switch (o) {
+//^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    case ObjectET1? _?:
+      return "not exhaustive";
+  }
+}
+
+String test8(bool? o) {
+  switch (o) {
+//^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    case ObjectET2? _?:
+      return "not exhaustive";
+  }
+}
+
+main() {
+  test1(null);
+  test2(null);
+  test3(null);
+  test4(null);
+  test5(null);
+  test6(null);
+  test7(null);
+  test8(null);
+}

LanguageFeatures/Extension-types/exhaustiveness_null_check_A01_t02.dart

@@ -0,0 +1,88 @@
+// 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 The lifted space union for a pattern with matched value type M is
+/// ...
+/// Null-check pattern:
+/// i. Let S be the expanded spaces of the lifted space union of the subpattern.
+/// ii. Remove any unions in S that have type Null. A null-check pattern
+///   specifically does not match null, so even if the subpattern would handle
+///   it, it will never see it.
+/// iii. The result is S.
+///
+/// @description Check that a null-check pattern removes any unions in `S` that
+/// have type `Null`. Test switch expression
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+extension type const ObjectET1(Object _) {}
+extension type const ObjectET2(Object _) implements Object {}
+
+String test1(ObjectET1? o) => switch (o) {
+//                            ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      Object? _? => "not exhaustive"
+    };
+
+String test2(ObjectET2? o) => switch (o) {
+//                            ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      Object? _? => "not exhaustive"
+    };
+
+String test3(ObjectET1? o) => switch (o) {
+//                            ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      ObjectET1? _? => "not exhaustive"
+    };
+
+String test4(ObjectET1? o) => switch (o) {
+//                            ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      ObjectET2? _? => "not exhaustive"
+    };
+
+String test5(ObjectET2? o) => switch (o) {
+//                            ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      ObjectET1? _? => "not exhaustive"
+    };
+
+String test6(ObjectET2? o) => switch (o) {
+//                            ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      ObjectET2? _? => "not exhaustive"
+    };
+
+String test7(Object? o) => switch (o) {
+//                         ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      ObjectET1? _? => "not exhaustive"
+    };
+
+String test8(Object? o) => switch (o) {
+//                         ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      ObjectET2? _? => "not exhaustive"
+    };
+
+main() {
+  test1(null);
+  test2(null);
+  test3(null);
+  test4(null);
+  test5(null);
+  test6(null);
+  test7(null);
+  test8(null);
+}

LanguageFeatures/Extension-types/exhaustiveness_null_check_A02_t01.dart

@@ -0,0 +1,135 @@
+// 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 The lifted space union for a pattern with matched value type M is
+/// ...
+/// Null-check pattern:
+/// i. Let S be the expanded spaces of the lifted space union of the subpattern.
+/// ii. Remove any unions in S that have type Null. A null-check pattern
+///   specifically does not match null, so even if the subpattern would handle
+///   it, it will never see it.
+/// iii. The result is S.
+///
+/// @description Check that a null-check pattern removes any unions in `S` that
+/// have type `Null`. Test switch statement
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+import "../../Utils/expect.dart";
+import "../Patterns/exhaustiveness/exhaustiveness_lib.dart";
+
+extension type CardET1<T>(Card<T> _) {}
+extension type CardET2<T>(Card<T> _) implements Card<T> {}
+extension type FaceET1<T>(Face<T> _) {}
+extension type FaceET2<T>(Face<T> _) implements Face<T> {}
+extension type PipET1<T>(Pip<T> _) {}
+extension type PipET2<T>(Pip<T> _) implements Pip<T> {}
+
+String test1(CardET1? c) {
+  switch (c) {
+    case Pip? _?:
+      return "Pip";
+    case Face? _?:
+      return "Face";
+    case Null _:
+      return "null";
+  }
+}
+
+String test2(CardET2? c) {
+  switch (c) {
+    case Pip? _?:
+      return "Pip";
+    case Face? _?:
+      return "Face";
+    case Null _:
+    return "null";
+  }
+}
+
+String test3(CardET1? c) {
+  switch (c) {
+    case PipET1? _?:
+      return "Pip";
+    case FaceET1? _?:
+      return "Face";
+    case Null _:
+    return "null";
+  }
+}
+
+String test4(CardET2? c) {
+  switch (c) {
+    case PipET2? _?:
+      return "Pip";
+    case FaceET2? _?:
+      return "Face";
+    case Null _:
+    return "null";
+  }
+}
+
+String test5(CardET1? c) {
+  switch (c) {
+    case PipET2? _?:
+      return "Pip";
+    case FaceET2? _?:
+      return "Face";
+    case Null _:
+    return "null";
+  }
+}
+
+String test6(CardET2? c) {
+  switch (c) {
+    case PipET1? _?:
+      return "Pip";
+    case FaceET1? _?:
+      return "Face";
+    case Null _:
+    return "null";
+  }
+}
+
+String test7(Card? c) {
+  switch (c) {
+    case PipET1? _?:
+      return "Pip";
+    case FaceET1? _?:
+      return "Face";
+    case Null _:
+    return "null";
+  }
+}
+
+String test8(Card? c) {
+  switch (c) {
+    case PipET2? _?:
+      return "Pip";
+    case FaceET2? _?:
+      return "Face";
+    case Null _:
+    return "null";
+  }
+}
+
+main() {
+  Expect.equals("Pip", test1(CardET1(Pip(2, Suit.club))));
+  Expect.equals("null", test1(null));
+  Expect.equals("Face", test2(CardET2(Jack(Suit.club))));
+  Expect.equals("null", test2(null));
+  Expect.equals("Pip", test3(CardET1(Pip(2, Suit.club))));
+  Expect.equals("null", test3(null));
+  Expect.equals("Face", test4(CardET2(Jack(Suit.club))));
+  Expect.equals("null", test4(null));
+  Expect.equals("Pip", test5(CardET1(Pip(2, Suit.club))));
+  Expect.equals("null", test5(null));
+  Expect.equals("Face", test6(CardET2(Jack(Suit.club))));
+  Expect.equals("null", test6(null));
+  Expect.equals("Pip", test7(Pip(2, Suit.club)));
+  Expect.equals("null", test7(null));
+  Expect.equals("Face", test8(Jack(Suit.club)));
+  Expect.equals("null", test8(null));
+}