[dart2wasm] Add tests for switch case br_table handling.

Catches bug fixed by https://dart-review.googlesource.com/c/sdk/+/442300

Change-Id: I7c3f5439809e6fd3e3403b620ef1fef1db56dbe3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/442320
Reviewed-by: Nate Bosch <[email protected]>
Commit-Queue: Nate Biggs <[email protected]>

Author: natebiggs

tests/language/switch/enum_compare_test.dart

@@ -0,0 +1,224 @@
+// Copyright (c) 2025, 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.
+
+// Ensure that switch statements with various types compare case expressions
+// to the switch expression value correctly.
+
+import 'package:async_helper/async_helper.dart';
+import 'package:expect/expect.dart';
+
+enum Animal { cat, dog, mouse, lion, duck }
+
+enum LongEnum {
+  a,
+  b,
+  c,
+  d,
+  e,
+  f,
+  g,
+  h,
+  i,
+  j,
+  k,
+  l,
+  m,
+  n,
+  o,
+  p,
+  q,
+  r,
+  s,
+  t,
+  u,
+  v,
+  w,
+  x,
+  y,
+  z,
+  aa,
+  ab,
+  ac,
+  ad,
+  ae,
+  af,
+  ag,
+  ah,
+  ai,
+  aj,
+  ak,
+  al,
+  am,
+  an,
+  ao,
+  ap,
+  aq,
+  ar,
+  as,
+  at,
+  au,
+  av,
+  aw,
+  ax,
+  ay,
+  az,
+}
+
+const List<String> strings = ['cat', 'dog', 'mouse', 'lion', 'duck'];
+const List<int> ints = [1, 2, 3, 4, 5];
+const List<bool> bools = [true, false];
+
+void switches() {
+  for (final animal in Animal.values) {
+    switch (animal) {
+      case Animal.cat:
+        Expect.equals(animal, Animal.cat);
+      case Animal.dog:
+        Expect.equals(animal, Animal.dog);
+      case Animal.mouse:
+        Expect.equals(animal, Animal.mouse);
+      case Animal.lion:
+        Expect.equals(animal, Animal.lion);
+      case Animal.duck:
+        Expect.equals(animal, Animal.duck);
+    }
+  }
+
+  final longEnum = LongEnum.ad;
+  switch (longEnum) {
+    case LongEnum.a:
+      Expect.equals(LongEnum.a, LongEnum.a);
+    case LongEnum.b:
+      Expect.equals(LongEnum.b, LongEnum.b);
+    default:
+      Expect.equals(longEnum, LongEnum.ad);
+  }
+
+  for (final string in strings) {
+    switch (string) {
+      case 'cat':
+        Expect.equals(string, 'cat');
+      case 'dog':
+        Expect.equals(string, 'dog');
+      case 'mouse':
+        Expect.equals(string, 'mouse');
+      case 'lion':
+        Expect.equals(string, 'lion');
+      case 'duck':
+        Expect.equals(string, 'duck');
+      default:
+        Expect.fail('Unknown string');
+    }
+  }
+
+  for (final i in ints) {
+    switch (i) {
+      case 1:
+        Expect.equals(i, 1);
+      case 2:
+        Expect.equals(i, 2);
+      case 3:
+        Expect.equals(i, 3);
+      case 4:
+        Expect.equals(i, 4);
+      case 5:
+        Expect.equals(i, 5);
+      default:
+        Expect.fail('Unknown int');
+    }
+  }
+
+  for (final b in bools) {
+    switch (b) {
+      case true:
+        Expect.isTrue(b);
+      case false:
+        Expect.isFalse(b);
+    }
+  }
+}
+
+Future<void> asyncSwitches() async {
+  for (final animal in Animal.values) {
+    switch (animal) {
+      case Animal.cat:
+        await 'something';
+        Expect.equals(animal, Animal.cat);
+      case Animal.dog:
+        Expect.equals(animal, Animal.dog);
+      case Animal.mouse:
+        Expect.equals(animal, Animal.mouse);
+      case Animal.lion:
+        Expect.equals(animal, Animal.lion);
+      case Animal.duck:
+        Expect.equals(animal, Animal.duck);
+    }
+  }
+
+  final longEnum = LongEnum.ad;
+  switch (longEnum) {
+    case LongEnum.a:
+      await 'something';
+      Expect.equals(LongEnum.a, LongEnum.a);
+    case LongEnum.b:
+      Expect.equals(LongEnum.b, LongEnum.b);
+    default:
+      Expect.equals(longEnum, LongEnum.ad);
+  }
+
+  for (final string in strings) {
+    switch (string) {
+      case 'cat':
+        await 'something';
+        Expect.equals(string, 'cat');
+      case 'dog':
+        Expect.equals(string, 'dog');
+      case 'mouse':
+        Expect.equals(string, 'mouse');
+      case 'lion':
+        Expect.equals(string, 'lion');
+      case 'duck':
+        Expect.equals(string, 'duck');
+      default:
+        Expect.fail('Unknown string');
+    }
+  }
+
+  for (final i in ints) {
+    switch (i) {
+      case 1:
+        await 'something';
+        Expect.equals(i, 1);
+      case 2:
+        Expect.equals(i, 2);
+      case 3:
+        Expect.equals(i, 3);
+      case 4:
+        Expect.equals(i, 4);
+      case 5:
+        Expect.equals(i, 5);
+      default:
+        Expect.fail('Unknown int');
+    }
+  }
+
+  for (final b in bools) {
+    switch (b) {
+      case true:
+        await 'something';
+        Expect.isTrue(b);
+      case false:
+        Expect.isFalse(b);
+    }
+  }
+}
+
+Future<void> main() async {
+  asyncStart();
+
+  switches();
+  await asyncSwitches();
+
+  asyncEnd();
+}