diff --git a/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t01.dart b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t01.dart
new file mode 100644
index 0000000000..31e7710dfa
--- /dev/null
+++ b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t01.dart
@@ -0,0 +1,67 @@
+// Copyright (c) 2023, 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 Switch statements and expressions with a sealed class as a
+/// matched type are always exhaustive
+///
+/// @description Check that it is no compile-time error if the matched value
+/// type of a switch expression is an extension type with a sealed class as a
+/// representation type and the set of cases is an exhaustive set of object
+/// patterns
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+import "../../Utils/expect.dart";
+import "../Patterns/Exhaustiveness/exhaustiveness_lib.dart";
+
+extension type FaceET1<T>(Face<T> _) {}
+extension type FaceET2<T>(Face<T> _) implements Face<T> {}
+
+String test1_1(FaceET1 face) => switch (face) {
+      Jack() => 'Jack',
+      Queen() => 'Queen',
+      King(suit: _) => 'King'
+    };
+
+String test1_2(FaceET2 face) => switch (face) {
+      Jack() => 'Jack',
+      Queen() => 'Queen',
+      King(suit: _) => 'King'
+    };
+
+String test2_1(FaceET1<int> face) => switch (face) {
+      Jack<num>() => 'Jack',
+      Queen<int>() => 'Queen',
+      King<int>(suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade) =>
+        'King'
+    };
+
+String test2_2(FaceET2<int> face) => switch (face) {
+      Jack<num>() => 'Jack',
+      Queen<int>() => 'Queen',
+      King<int>(suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade) =>
+        'King'
+    };
+
+String test3_1<T extends num>(FaceET1<T> face) => switch (face) {
+      Jack<num>() && Jack<T>(oneEyed: _) => 'Jack',
+      Queen<num>() => 'Queen',
+      King<T>() => 'King'
+    };
+
+String test3_2<T extends num>(FaceET2<T> face) => switch (face) {
+      Jack<num>() && Jack<T>(oneEyed: _) => 'Jack',
+      Queen<num>() => 'Queen',
+      King<T>() => 'King'
+    };
+
+main() {
+  Expect.equals("King", test1_1(FaceET1(King(Suit.club))));
+  Expect.equals("King", test1_2(FaceET2(King(Suit.club))));
+  Expect.equals("King", test2_1(FaceET1(King(Suit.club))));
+  Expect.equals("King", test2_2(FaceET2(King(Suit.club))));
+  Expect.equals("King", test3_1<int>(FaceET1(King(Suit.club))));
+  Expect.equals("King", test3_2<int>(FaceET2(King(Suit.club))));
+}
diff --git a/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t02.dart b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t02.dart
new file mode 100644
index 0000000000..f38a8b1968
--- /dev/null
+++ b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t02.dart
@@ -0,0 +1,78 @@
+// Copyright (c) 2023, 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 Switch statements and expressions with a sealed class as a
+/// matched type are always exhaustive
+///
+/// @description Check that it is no compile-time error if the matched value
+/// type of a switch statement is an extension type with a sealed class as a
+/// representation type and the set of cases is exhaustive
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+import "../../Utils/expect.dart";
+import "../Patterns/Exhaustiveness/exhaustiveness_lib.dart";
+
+extension type FaceET1<T>(Face<T> _) {}
+extension type FaceET2<T>(Face<T> _) implements Face<T> {}
+
+String test1_1(FaceET1 face) {
+  switch (face) {
+    case Jack(): return 'Jack';
+    case Queen(): return 'Queen';
+    case King(suit: _): return 'King';
+  }
+}
+
+String test1_2(FaceET2 face) {
+  switch (face) {
+    case Jack(): return 'Jack';
+    case Queen(): return 'Queen';
+    case King(suit: _): return 'King';
+  }
+}
+
+String test2_1(FaceET1<int> face) {
+  switch (face) {
+    case Jack<num>(): return 'Jack';
+    case Queen<int>(): return 'Queen';
+    case King<int>(suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade):
+        return 'King';
+  }
+}
+
+String test2_2(FaceET2<int> face) {
+  switch (face) {
+    case Jack<num>(): return 'Jack';
+    case Queen<int>(): return 'Queen';
+    case King<int>(suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade):
+      return 'King';
+    }
+}
+
+String test3_1<T extends num>(FaceET1<T> face) {
+  switch (face) {
+    case Jack<num>() && Jack<T>(oneEyed: _): return 'Jack';
+    case Queen<num>(): return 'Queen';
+    case King<T>(): return 'King';
+  }
+}
+
+String test3_2<T extends num>(FaceET2<T> face) {
+  switch (face) {
+    case Jack<num>() && Jack<T>(oneEyed: _): return 'Jack';
+    case Queen<num>(): return 'Queen';
+    case King<T>(): return 'King';
+  }
+}
+
+main() {
+  Expect.equals("King", test1_1(FaceET1(King(Suit.club))));
+  Expect.equals("King", test1_2(FaceET2(King(Suit.club))));
+  Expect.equals("King", test2_1(FaceET1(King(Suit.club))));
+  Expect.equals("King", test2_2(FaceET2(King(Suit.club))));
+  Expect.equals("King", test3_1<int>(FaceET1(King(Suit.club))));
+  Expect.equals("King", test3_2<int>(FaceET2(King(Suit.club))));
+}
diff --git a/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t03.dart b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t03.dart
new file mode 100644
index 0000000000..4a60a71dbf
--- /dev/null
+++ b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t03.dart
@@ -0,0 +1,44 @@
+// Copyright (c) 2023, 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 Switch statements and expressions with a sealed class as a
+/// matched type are always exhaustive
+///
+/// @description Check that it is no compile-time error if the matched value
+/// type of a switch expression is a sealed class as and the set of cases is an
+/// exhaustive set of object patterns with extension types
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+import "../../Utils/expect.dart";
+import "../Patterns/Exhaustiveness/exhaustiveness_lib.dart";
+
+extension type JackET<T>(Jack<T> _) implements Jack<T> {}
+extension type QueenET<T>(Queen<T> _) implements Queen<T> {}
+extension type KingET<T>(King<T> _) implements King<T> {}
+
+String test1(Face face) => switch (face) {
+      JackET() || QueenET() => 'Jack or Queen',
+      KingET(suit: _) => 'King'
+    };
+
+String test2(Face<int> face) => switch (face) {
+      JackET<num>() || QueenET<int>() => 'Jack or Queen',
+      KingET<int>(
+        suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade
+      ) => 'King'
+    };
+
+String test3<T extends num>(Face<T> face) => switch (face) {
+      JackET<num>() && JackET<T>(oneEyed: _) => 'Jack',
+      QueenET<num>() => 'Queen',
+      KingET<T>() => 'King'
+    };
+
+main() {
+  Expect.equals("Jack or Queen", test1(Jack(Suit.club)));
+  Expect.equals("Jack or Queen", test2(Jack(Suit.club)));
+  Expect.equals("King", test3<int>(King(Suit.club)));
+}
diff --git a/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t04.dart b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t04.dart
new file mode 100644
index 0000000000..343085652e
--- /dev/null
+++ b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t04.dart
@@ -0,0 +1,54 @@
+// Copyright (c) 2023, 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 Switch statements and expressions with a sealed class as a
+/// matched type are always exhaustive
+///
+/// @description Check that it is no compile-time error if the matched value
+/// type of a switch statement is a sealed class as and the set of cases is an
+/// exhaustive set of object patterns with extension types
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+import "../../Utils/expect.dart";
+import "../Patterns/Exhaustiveness/exhaustiveness_lib.dart";
+
+extension type JackET<T>(Jack<T> _) implements Jack<T> {}
+extension type QueenET<T>(Queen<T> _) implements Queen<T> {}
+extension type KingET<T>(King<T> _) implements King<T> {}
+
+String test1(Face face) {
+  switch (face) {
+    case JackET() || QueenET():
+      return 'Jack or Queen';
+    case KingET(suit: _):
+      return 'King';
+  }
+}
+
+String test2(Face<int> face) {
+  switch (face) {
+    case JackET<num>() || QueenET<int>():
+      return 'Jack or Queen';
+    case KingET<int>(
+        suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade
+      ):
+      return 'King';
+  }
+}
+
+String test3<T extends num>(Face<T> face) {
+  switch (face) {
+    case JackET<num>() && JackET<T>(oneEyed: _): return 'Jack';
+    case QueenET<num>(): return 'Queen';
+    case KingET<T>(): return 'King';
+  }
+}
+
+main() {
+  Expect.equals("Jack or Queen", test1(Jack(Suit.club)));
+  Expect.equals("Jack or Queen", test2(Jack(Suit.club)));
+  Expect.equals("King", test3<int>(King(Suit.club)));
+}
diff --git a/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t05.dart b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t05.dart
new file mode 100644
index 0000000000..61676f9e37
--- /dev/null
+++ b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t05.dart
@@ -0,0 +1,69 @@
+// Copyright (c) 2023, 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 Switch statements and expressions with a sealed class as a
+/// matched type are always exhaustive
+///
+/// @description Check that it is no compile-time error if the matched value
+/// type of a switch is an extension type with a sealed class as a
+/// representation type and the set of cases is an exhaustive set of object
+/// patterns with extension types
+/// @author sgrekhov22@gmail.com
+
+// SharedOptions=--enable-experiment=inline-class
+
+import "../../Utils/expect.dart";
+import "../Patterns/Exhaustiveness/exhaustiveness_lib.dart";
+
+extension type FaceET1<T>(Face<T> _) {}
+extension type FaceET2<T>(Face<T> _) implements Face<T> {}
+
+extension type JackET<T>(Jack<T> _) implements Jack<T> {}
+extension type QueenET<T>(Queen<T> _) implements Queen<T> {}
+extension type KingET<T>(King<T> _) implements King<T> {}
+
+String test1_1(FaceET1 face) => switch (face) {
+      JackET() || QueenET() => 'Jack or Queen',
+      KingET(suit: _) => 'King'
+    };
+
+String test1_2(FaceET2 face) => switch (face) {
+      JackET() || QueenET() => 'Jack or Queen',
+      KingET(suit: _) => 'King'
+    };
+
+String test2_1(FaceET1<int> face) => switch (face) {
+      JackET<num>() || QueenET<int>() => 'Jack or Queen',
+      KingET<int>(
+        suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade
+      ) => 'King'
+    };
+
+String test2_2(FaceET2<int> face) => switch (face) {
+      JackET<num>() || QueenET<int>() => 'Jack or Queen',
+      KingET<int>(
+        suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade
+      ) => 'King'
+    };
+
+String test3_1<T extends num>(FaceET1<T> face) => switch (face) {
+      JackET<num>() && JackET<T>(oneEyed: _) => 'Jack',
+      QueenET<num>() => 'Queen',
+      KingET<T>() => 'King'
+    };
+
+String test3_2<T extends num>(FaceET2<T> face) => switch (face) {
+      JackET<num>() && JackET<T>(oneEyed: _) => 'Jack',
+      QueenET<num>() => 'Queen',
+      KingET<T>() => 'King'
+    };
+
+main() {
+  Expect.equals("Jack or Queen", test1_1(FaceET1(Jack(Suit.club))));
+  Expect.equals("Jack or Queen", test1_2(FaceET2(Jack(Suit.club))));
+  Expect.equals("Jack or Queen", test2_1(FaceET1(Jack(Suit.club))));
+  Expect.equals("Jack or Queen", test2_2(FaceET2(Jack(Suit.club))));
+  Expect.equals("King", test3_1<int>(FaceET1(King(Suit.club))));
+  Expect.equals("King", test3_2<int>(FaceET2(King(Suit.club))));
+}
diff --git a/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t06.dart b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t06.dart
new file mode 100644
index 0000000000..9ae5b0c251
--- /dev/null
+++ b/LanguageFeatures/Extension-types/exhaustiveness_object_A01_t06.dart
@@ -0,0 +1,90 @@
+// Copyright (c) 2023, 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 Switch statements and expressions with a sealed class as a
+/// matched type are always exhaustive
+///
+/// @description Check that it is no compile-time error if the matched value
+/// type of a switch is an statement type with a sealed class as a
+/// representation type and the set of cases is an exhaustive set of object
+/// patterns with extension types
+/// @author sgrekhov22@gmail.com
+/// @issue 54444
+
+// SharedOptions=--enable-experiment=inline-class
+
+import "../../Utils/expect.dart";
+import "../Patterns/Exhaustiveness/exhaustiveness_lib.dart";
+
+extension type FaceET1<T>(Face<T> _) {}
+extension type FaceET2<T>(Face<T> _) implements Face<T> {}
+
+extension type JackET<T>(Jack<T> _) implements Jack<T> {}
+extension type QueenET<T>(Queen<T> _) implements Queen<T> {}
+extension type KingET<T>(King<T> _) implements King<T> {}
+
+String test1_1(FaceET1 face) {
+  switch (face) {
+    case JackET() || QueenET():
+      return 'Jack or Queen';
+    case KingET(suit: _):
+      return 'King';
+  }
+}
+
+String test1_2(FaceET2 face) {
+  switch (face) {
+    case JackET() || QueenET():
+      return 'Jack or Queen';
+    case KingET(suit: _):
+      return 'King';
+  }
+}
+
+String test2_1(FaceET1<int> face) {
+  switch (face) {
+    case JackET<num>() || QueenET<int>():
+      return 'Jack or Queen';
+    case KingET<int>(
+        suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade
+      ):
+      return 'King';
+  }
+}
+
+String test2_2(FaceET2<int> face) {
+  switch (face) {
+    case JackET<num>() || QueenET<int>():
+      return 'Jack or Queen';
+    case KingET<int>(
+        suit: Suit.club || Suit.diamond || Suit.heart || Suit.spade
+      ):
+      return 'King';
+  }
+}
+
+String test3_1<T extends num>(FaceET1<T> face) {
+  switch (face) {
+    case JackET<num>() && JackET<T>(oneEyed: _): return 'Jack';
+    case QueenET<num>(): return 'Queen';
+    case KingET<T>(): return 'King';
+  }
+}
+
+String test3_2<T extends num>(FaceET2<T> face) {
+  switch (face) {
+    case JackET<num>() && JackET<T>(oneEyed: _): return 'Jack';
+    case QueenET<num>(): return 'Queen';
+    case KingET<T>(): return 'King';
+  }
+}
+
+main() {
+  Expect.equals("Jack or Queen", test1_1(FaceET1(Jack(Suit.club))));
+  Expect.equals("Jack or Queen", test1_2(FaceET2(Jack(Suit.club))));
+  Expect.equals("Jack or Queen", test2_1(FaceET1(Jack(Suit.club))));
+  Expect.equals("Jack or Queen", test2_2(FaceET2(Jack(Suit.club))));
+  Expect.equals("King", test3_1<int>(FaceET1(King(Suit.club))));
+  Expect.equals("King", test3_2<int>(FaceET2(King(Suit.club))));
+}