[test] Adding tests for records with web semantics for numerics.

See: #52480

Change-Id: Ife785a2f77579b93854779e43ac349342ac06af3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/305480
Reviewed-by: Nicholas Shahan <[email protected]>

tests/web/record_numbers_test.dart

@@ -0,0 +1,36 @@
+// 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.
+
+// Tests record numeric subtyping rules with web semantics.
+// Regression test for https://github.com/dart-lang/sdk/issues/52480
+
+import "package:expect/expect.dart";
+
+main() {
+  Expect.notSubtype<(int, int), (double, double)>();
+  Expect.notSubtype<(int, double), (double, double)>();
+  Expect.notSubtype<(double, double), (int, int)>();
+  Expect.notSubtype<(int, double), (int, int)>();
+
+  Object mixedTuple = (0, 0.1);
+  (double, double) doubleTuple = (0.0, 0.1);
+  Object someTuple = doubleTuple;
+
+  Expect.type<(double, double)>(mixedTuple);
+  Expect.type<(int, double)>(mixedTuple);
+  Expect.type<(double, double)>(someTuple);
+  Expect.type<(int, double)>(someTuple);
+
+  dynamic dynamicIntTuple = (4, 4);
+  dynamic dynamicDoubleTuple = doubleTuple;
+
+  Expect.type<(int, int)>(dynamicIntTuple);
+  Expect.type<(int, double)>(dynamicIntTuple);
+  Expect.type<(double, int)>(dynamicIntTuple);
+  Expect.type<(double, double)>(dynamicIntTuple);
+  Expect.notType<(int, int)>(dynamicDoubleTuple);
+  Expect.type<(int, double)>(dynamicDoubleTuple);
+  Expect.notType<(double, int)>(dynamicDoubleTuple);
+  Expect.type<(double, double)>(dynamicDoubleTuple);
+}