add tests for Promise.withResolvers proposal

features.txt

@@ -108,6 +108,10 @@ json-parse-with-source
 # https://github.com/tc39/proposal-iterator-helpers
 iterator-helpers
 
+# Promise.withResolvers
+# https://github.com/tc30/proposal-promise-with-resolvers
+promise-with-resolvers
+
 ## Standard language features
 #
 # Language features that have been included in a published version of the

test/built-ins/Promise/withResolvers/ctx-ctor.js

@@ -0,0 +1,15 @@
+// Copyright (C) 2023 Peter Klecha. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Promise.withResolvers produces instances of the reciever
+features: [promise-with-resolvers]
+---*/
+
+class SubPromise extends Promise {}
+
+var instance = Promise.withResolvers.call(SubPromise);
+
+assert.sameValue(instance.promise.constructor, SubPromise);
+assert.sameValue(instance.promise instanceof SubPromise, true);
+

test/built-ins/Promise/withResolvers/ctx-non-ctor.js

@@ -0,0 +1,11 @@
+// Copyright (C) 2023 Peter Klecha. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Promise.withResolvers errors when the reciever is not a constructor
+features: [promise-with-resolvers]
+---*/
+
+assert.throws(TypeError, function() {
+  Promise.withResolvers.call(eval);
+});

test/built-ins/Promise/withResolvers/ctx-non-object.js

@@ -0,0 +1,31 @@
+// Copyright (C) 2023 Peter Klecha. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Promise.withResolvers errors when the receiver is not an object
+features: [promise-with-resolvers]
+---*/
+
+assert.throws(TypeError, function() {
+  Promise.withResolvers.call(undefined);
+});
+
+assert.throws(TypeError, function() {
+  Promise.withResolvers.call(null);
+});
+
+assert.throws(TypeError, function() {
+  Promise.withResolvers.call(86);
+});
+  
+  assert.throws(TypeError, function() {
+    Promise.withResolvers.call('string');
+  });
+  
+  assert.throws(TypeError, function() {
+    Promise.withResolvers.call(true);
+  });
+  
+  assert.throws(TypeError, function() {
+    Promise.withResolvers.call(Symbol());
+  });

test/built-ins/Promise/withResolvers/promise.js

@@ -0,0 +1,14 @@
+// Copyright (C) 2023 Peter Klecha. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Promise.withResolvers return value has a property called "promise" which is a Promise
+features: [promise-with-resolvers]
+---*/
+
+
+var instance = Promise.withResolvers();
+
+assert.sameValue(instance.promise.constructor, Promise);
+assert.sameValue(instance.promise instanceof Promise, true);
+

test/built-ins/Promise/withResolvers/resolvers.js

@@ -0,0 +1,15 @@
+// Copyright (C) 2023 Peter Klecha. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Promise.withResolvers return value has properties called "resolve" and "reject" which are unary functions
+features: [promise-with-resolvers]
+---*/
+
+
+var instance = Promise.withResolvers();
+
+assert.sameValue(typeof instance.resolve, 'function', 'type of resolve property');
+assert.sameValue(instance.resolve.length, 1, 'length of resolve property');
+assert.sameValue(typeof instance.reject, 'function', 'type of reject property');
+assert.sameValue(instance.reject.length, 1, 'length of reject property');

test/built-ins/Promise/withResolvers/result.js

@@ -0,0 +1,17 @@
+// Copyright (C) 2023 Peter Klecha. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Promise.withResolvers result is an object with keys "promise", "reject", and "resolve"
+features: [promise-with-resolvers]
+---*/
+
+
+var instance = Promise.withResolvers();
+
+assert.sameValue(typeof instance, "object");
+assert.notSameValue(instance, null);
+assert(Object.hasOwn(instance, "promise"));
+assert(Object.hasOwn(instance, "resolve"));
+assert(Object.hasOwn(instance, "reject"));
+