add tests for proposed faster-promise-try change

test/built-ins/Promise/try/avoids-wrap-for-subclass.js

@@ -0,0 +1,22 @@
+// Copyright (C) 2026 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: When the callback passed to PromiseSubclass.try returns a PromiseSubclass, it is not wrapped
+esid: sec-promise.try
+features: [promise-try, class]
+---*/
+
+class SubPromise extends Promise {
+  constructor(executor) {
+    super(executor);
+  }
+}
+
+var sentinel = SubPromise.resolve();
+assert(sentinel instanceof SubPromise);
+
+var returnValue = SubPromise.try(function () {
+  return sentinel;
+});
+assert.sameValue(returnValue, sentinel);

test/built-ins/Promise/try/avoids-wrap.js

@@ -0,0 +1,15 @@
+// Copyright (C) 2026 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: When the callback passed to Promise.try returns a Promise, it is not wrapped
+esid: sec-promise.try
+features: [promise-try]
+---*/
+
+var sentinel = Promise.resolve();
+
+var returnValue = Promise.try(function () {
+  return sentinel;
+});
+assert.sameValue(returnValue, sentinel);

test/built-ins/Promise/try/ctx-ctor-for-error.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2026 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Promise.try produces instances of the receiver for errors
+esid: sec-promise.try
+features: [promise-try, class]
+flags: [async]
+includes: [asyncHelpers.js]
+---*/
+
+class SubPromise extends Promise {
+  constructor(executor) {
+    super(executor);
+  }
+}
+
+var error = {};
+var instance = SubPromise.try(function () {
+  throw error;
+});
+assert(instance instanceof SubPromise);
+
+asyncTest(function() {
+  return instance.then(function () {
+    throw new Test262Error('Promise.try given a throwing function should throw');
+  }, function (observedError) {
+    assert.sameValue(observedError, error);
+  });
+});