Add WebAssembly[Symbol.toStringTag] test

wasm/jsapi/namespace-object-class-string.any.js

@@ -0,0 +1,40 @@
+"use strict";
+// https://heycam.github.io/webidl/#es-namespaces
+// https://webassembly.github.io/spec/js-api/#namespacedef-webassembly
+
+test(() => {
+  assert_own_property(WebAssembly, Symbol.toStringTag);
+
+  const propDesc = Object.getOwnPropertyDescriptor(WebAssembly, Symbol.toStringTag);
+  assert_equals(propDesc.value, "WebAssembly", "value");
+  assert_equals(propDesc.writable, false, "writable");
+  assert_equals(propDesc.enumerable, false, "enumerable");
+  assert_equals(propDesc.configurable, true, "configurable");
+}, "@@toStringTag exists on the namespace object with the appropriate descriptor");
+
+test(() => {
+  assert_equals(WebAssembly.toString(), "[object WebAssembly]");
+  assert_equals(Object.prototype.toString.call(WebAssembly), "[object WebAssembly]");
+}, "Object.prototype.toString applied to the namespace object");
+
+test(t => {
+  assert_own_property(WebAssembly, Symbol.toStringTag, "Precondition: @@toStringTag on the namespace object");
+  t.add_cleanup(() => {
+    Object.defineProperty(WebAssembly, Symbol.toStringTag, { value: "WebAssembly" });
+  });
+
+  Object.defineProperty(WebAssembly, Symbol.toStringTag, { value: "Test" });
+  assert_equals(WebAssembly.toString(), "[object Test]");
+  assert_equals(Object.prototype.toString.call(WebAssembly), "[object Test]");
+}, "Object.prototype.toString applied after modifying the namespace object's @@toStringTag");
+
+test(t => {
+  assert_own_property(WebAssembly, Symbol.toStringTag, "Precondition: @@toStringTag on the namespace object");
+  t.add_cleanup(() => {
+    Object.defineProperty(WebAssembly, Symbol.toStringTag, { value: "WebAssembly" });
+  });
+
+  assert_true(delete WebAssembly[Symbol.toStringTag]);
+  assert_equals(WebAssembly.toString(), "[object Object]");
+  assert_equals(Object.prototype.toString.call(WebAssembly), "[object Object]");
+}, "Object.prototype.toString applied after deleting @@toStringTag");