Tools/TestWebKitAPI/Tests/WebKitCocoa/AsyncFunction.mm - WebKit - Git at Google

 /*
  * Copyright (C) 2019 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #import "config.h"

 #import "PlatformUtilities.h"
 #import "Test.h"
 #import "TestWKWebView.h"
 #import <WebKit/WKWebViewPrivate.h>
 #import <WebKit/_WKContentWorld.h>

 namespace TestWebKitAPI {

 TEST(AsyncFunction, Basic)
 {
     auto webView = adoptNS([[TestWKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600)]);
     NSError *error;

     // Function with no return value.
     // Returns JavaScript undefined which translates to nil.
     id result = [webView objectByCallingAsyncFunction:@"1" withArguments:nil error:&error];
     EXPECT_NULL(error);
     EXPECT_EQ(result, nil);

     // Function returns explicit null.
     // Returns JavaScript null which translates to NSNull.
     result = [webView objectByCallingAsyncFunction:@"return null" withArguments:nil error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([result isKindOfClass:[NSNull class]]);

     // Function returns a number.
     result = [webView objectByCallingAsyncFunction:@"return 1" withArguments:nil error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
     EXPECT_TRUE([result isEqualToNumber:@1]);

     // Function returns a string.
     result = [webView objectByCallingAsyncFunction:@"return '1'" withArguments:nil error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([result isKindOfClass:[NSString class]]);
     EXPECT_TRUE([result isEqualToString:@"1"]);

     // Takes multiple arguments.
     result = [webView objectByCallingAsyncFunction:@"return a + b" withArguments:@{ @"a" : @40, @"b" : @2 } error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
     EXPECT_TRUE([result isEqualToNumber:@42]);

     // Takes multiple arguments of different types, follows javascripts "type appending" rules.
     result = [webView objectByCallingAsyncFunction:@"return foo + bar" withArguments:@{ @"foo" : @"foo", @"bar" : @42 } error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([result isKindOfClass:[NSString class]]);
     EXPECT_TRUE([result isEqualToString:@"foo42"]);

     // Invalid JavaScript, should return an error.
     result = [webView objectByCallingAsyncFunction:@"retunr null" withArguments:nil error:&error];
     EXPECT_FALSE(error == nil);
     EXPECT_NULL(result);
 }

 TEST(AsyncFunction, InvalidArguments)
 {
     auto webView = adoptNS([[TestWKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600)]);
     NSError *error;

     // Values can only be NSString, NSNumber, NSDate, NSNull, NS(Mutable)Array, NS(Mutable)Dictionary, NSNull, and may only contain those 6 types.
     id result = [webView objectByCallingAsyncFunction:@"return 1" withArguments:@{ @"a" : [NSData data] } error:&error];
     EXPECT_NULL(result);
     EXPECT_FALSE(error == nil);

     result = [webView objectByCallingAsyncFunction:@"return 1" withArguments:@{ @"a" : @[ @1, [NSData data] ] } error:&error];
     EXPECT_NULL(result);
     EXPECT_FALSE(error == nil);

     // References an argument that was not provided.
     result = [webView objectByCallingAsyncFunction:@"return a + b" withArguments:@{ @"a" : @40 } error:&error];
     EXPECT_NULL(result);
     EXPECT_FALSE(error == nil);
 }

 TEST(AsyncFunction, RoundTrip)
 {
     auto webView = adoptNS([[TestWKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600)]);
     NSError *error;

     // Tests round tripping a whole bunch of argument inputs and verifying the result.

     id value = @42;
     id arguments = @{ @"a" : value };
     id result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);

     value = [NSNull null];
     arguments = @{ @"a" : value };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);

     value = @"Foo";
     arguments = @{ @"a" : value };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);

     value = [NSDate dateWithTimeIntervalSinceReferenceDate:0];
     arguments = @{ @"a" : value };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);

     value = @[ @1, @2 ];
     arguments = @{ @"a" : value };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);

     NSMutableArray *mutableArray = [[NSMutableArray alloc] init];
     [mutableArray addObject:value];
     arguments = @{ @"a" : mutableArray };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([mutableArray isEqual:result]);
     [mutableArray release];

     value = @[ @"foo", [NSDate dateWithTimeIntervalSinceReferenceDate:0] ];
     arguments = @{ @"a" : value };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);

     value = @{ @"a" : @1, @"b" : @2 };
     arguments = @{ @"a" : value };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);

     NSMutableDictionary<NSString *, id> *mutableDictionary = [[NSMutableDictionary alloc] init];
     mutableDictionary[@"foo"] = value;
     arguments = @{ @"a" : mutableDictionary };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([mutableDictionary isEqual:result]);
     [mutableDictionary release];

     value = @{ @"a" : @"foo", @"b" : [NSDate dateWithTimeIntervalSinceReferenceDate:0] };
     arguments = @{ @"a" : value };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);

     value = @{ @"a" : @{ @"a" : @1 } };
     arguments = @{ @"a" : value };
     result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
     EXPECT_NULL(error);
     EXPECT_TRUE([value isEqual:result]);
 }

 static void tryGCPromise(WKWebView *webView, bool& done)
 {
     if (done)
         return;

     NSString *functionBody = @"return new Promise(function(resolve, reject) { })";
     [webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
         EXPECT_NULL(result);
         EXPECT_TRUE(error != nil);
         EXPECT_TRUE([[error description] containsString:@"no longer reachable"]);
         done = true;
     }];

     dispatch_async(dispatch_get_main_queue(), ^{ tryGCPromise(webView, done); });
 }

 TEST(AsyncFunction, Promise)
 {
     auto webView = adoptNS([[TestWKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600)]);

     NSString *functionBody = @"return new Promise(function(resolve, reject) { setTimeout(function(){ resolve(42) }, 0); })";

     bool done = false;
     [webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
         EXPECT_NULL(error);
         EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
         EXPECT_TRUE([result isEqualToNumber:@42]);
         done = true;
     }];
     TestWebKitAPI::Util::run(&done);
     done = false;

     functionBody = @"return new Promise(function(resolve, reject) { setTimeout(function(){ reject('Rejected!') }, 0); })";

     done = false;
     [webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
         EXPECT_NULL(result);
         EXPECT_TRUE(error != nil);
         EXPECT_TRUE([[error description] containsString:@"Rejected!"]);
         done = true;
     }];
     TestWebKitAPI::Util::run(&done);

     functionBody = @"let p = new Proxy(function(resolve, reject) { setTimeout(function() { resolve(42); }, 0); }, { }); return { then: p };";

     done = false;
     [webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
         EXPECT_NULL(error);
         EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
         EXPECT_TRUE([result isEqualToNumber:@42]);
         done = true;
     }];
     TestWebKitAPI::Util::run(&done);

     functionBody = @"let p = new Proxy(function(resolve, reject) { setTimeout(function() { reject('Rejected!'); }, 0); }, { }); return { then: p };";

     done = false;
     [webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
         EXPECT_NULL(result);
         EXPECT_TRUE(error != nil);
         EXPECT_TRUE([[error description] containsString:@"Rejected!"]);
         done = true;
     }];
     TestWebKitAPI::Util::run(&done);

     // Verify we can await for a promise to be resolved before returning.
     functionBody = @"var r = 0; var p = new Promise(function(fulfill, reject) { setTimeout(function(){ r = 42; fulfill(); }, 5);}); await p; return r;";

     done = false;
     [webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
         EXPECT_NULL(error);
         EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
         EXPECT_TRUE([result isEqualToNumber:@42]);
         done = true;
     }];
     TestWebKitAPI::Util::run(&done);

     // Returning an already resolved promise gives the value it was resolved with.
     functionBody = @"var p = new Promise(function(fulfill, reject) { setTimeout(function(){ fulfill('Fulfilled!') }, 5);}); await p; return p;";

     done = false;
     [webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
         EXPECT_NULL(error);
         EXPECT_TRUE([result isKindOfClass:[NSString class]]);
         EXPECT_TRUE([result isEqualToString:@"Fulfilled!"]);
         done = true;
     }];
     TestWebKitAPI::Util::run(&done);

     // Chaining thenables should work.
     functionBody = @"var p = new Promise(function (r) { r(new Promise(function (r) { r(42); })); }); await p; return 'Done';";

     done = false;
     [webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
         EXPECT_NULL(error);
         EXPECT_TRUE([result isKindOfClass:[NSString class]]);
         EXPECT_TRUE([result isEqualToString:@"Done"]);
         done = true;
     }];
     TestWebKitAPI::Util::run(&done);

     done = false;
     tryGCPromise(webView.get(), done);
     TestWebKitAPI::Util::run(&done);
 }

 }
	/*
	* Copyright (C) 2019 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#import "config.h"

	#import "PlatformUtilities.h"
	#import "Test.h"
	#import "TestWKWebView.h"
	#import <WebKit/WKWebViewPrivate.h>
	#import <WebKit/_WKContentWorld.h>

	namespace TestWebKitAPI {

	TEST(AsyncFunction, Basic)
	{
	auto webView = adoptNS([[TestWKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600)]);
	NSError *error;

	// Function with no return value.
	// Returns JavaScript undefined which translates to nil.
	id result = [webView objectByCallingAsyncFunction:@"1" withArguments:nil error:&error];
	EXPECT_NULL(error);
	EXPECT_EQ(result, nil);

	// Function returns explicit null.
	// Returns JavaScript null which translates to NSNull.
	result = [webView objectByCallingAsyncFunction:@"return null" withArguments:nil error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSNull class]]);

	// Function returns a number.
	result = [webView objectByCallingAsyncFunction:@"return 1" withArguments:nil error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
	EXPECT_TRUE([result isEqualToNumber:@1]);

	// Function returns a string.
	result = [webView objectByCallingAsyncFunction:@"return '1'" withArguments:nil error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSString class]]);
	EXPECT_TRUE([result isEqualToString:@"1"]);

	// Takes multiple arguments.
	result = [webView objectByCallingAsyncFunction:@"return a + b" withArguments:@{ @"a" : @40, @"b" : @2 } error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
	EXPECT_TRUE([result isEqualToNumber:@42]);

	// Takes multiple arguments of different types, follows javascripts "type appending" rules.
	result = [webView objectByCallingAsyncFunction:@"return foo + bar" withArguments:@{ @"foo" : @"foo", @"bar" : @42 } error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSString class]]);
	EXPECT_TRUE([result isEqualToString:@"foo42"]);

	// Invalid JavaScript, should return an error.
	result = [webView objectByCallingAsyncFunction:@"retunr null" withArguments:nil error:&error];
	EXPECT_FALSE(error == nil);
	EXPECT_NULL(result);
	}

	TEST(AsyncFunction, InvalidArguments)
	{
	auto webView = adoptNS([[TestWKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600)]);
	NSError *error;

	// Values can only be NSString, NSNumber, NSDate, NSNull, NS(Mutable)Array, NS(Mutable)Dictionary, NSNull, and may only contain those 6 types.
	id result = [webView objectByCallingAsyncFunction:@"return 1" withArguments:@{ @"a" : [NSData data] } error:&error];
	EXPECT_NULL(result);
	EXPECT_FALSE(error == nil);

	result = [webView objectByCallingAsyncFunction:@"return 1" withArguments:@{ @"a" : @[ @1, [NSData data] ] } error:&error];
	EXPECT_NULL(result);
	EXPECT_FALSE(error == nil);

	// References an argument that was not provided.
	result = [webView objectByCallingAsyncFunction:@"return a + b" withArguments:@{ @"a" : @40 } error:&error];
	EXPECT_NULL(result);
	EXPECT_FALSE(error == nil);
	}

	TEST(AsyncFunction, RoundTrip)
	{
	auto webView = adoptNS([[TestWKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600)]);
	NSError *error;

	// Tests round tripping a whole bunch of argument inputs and verifying the result.

	id value = @42;
	id arguments = @{ @"a" : value };
	id result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);

	value = [NSNull null];
	arguments = @{ @"a" : value };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);

	value = @"Foo";
	arguments = @{ @"a" : value };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);

	value = [NSDate dateWithTimeIntervalSinceReferenceDate:0];
	arguments = @{ @"a" : value };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);

	value = @[ @1, @2 ];
	arguments = @{ @"a" : value };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);

	NSMutableArray *mutableArray = [[NSMutableArray alloc] init];
	[mutableArray addObject:value];
	arguments = @{ @"a" : mutableArray };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([mutableArray isEqual:result]);
	[mutableArray release];

	value = @[ @"foo", [NSDate dateWithTimeIntervalSinceReferenceDate:0] ];
	arguments = @{ @"a" : value };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);

	value = @{ @"a" : @1, @"b" : @2 };
	arguments = @{ @"a" : value };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);

	NSMutableDictionary<NSString , id> mutableDictionary = [[NSMutableDictionary alloc] init];
	mutableDictionary[@"foo"] = value;
	arguments = @{ @"a" : mutableDictionary };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([mutableDictionary isEqual:result]);
	[mutableDictionary release];

	value = @{ @"a" : @"foo", @"b" : [NSDate dateWithTimeIntervalSinceReferenceDate:0] };
	arguments = @{ @"a" : value };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);

	value = @{ @"a" : @{ @"a" : @1 } };
	arguments = @{ @"a" : value };
	result = [webView objectByCallingAsyncFunction:@"return a" withArguments:arguments error:&error];
	EXPECT_NULL(error);
	EXPECT_TRUE([value isEqual:result]);
	}

	static void tryGCPromise(WKWebView *webView, bool& done)
	{
	if (done)
	return;

	NSString *functionBody = @"return new Promise(function(resolve, reject) { })";
	[webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
	EXPECT_NULL(result);
	EXPECT_TRUE(error != nil);
	EXPECT_TRUE([[error description] containsString:@"no longer reachable"]);
	done = true;
	}];

	dispatch_async(dispatch_get_main_queue(), ^{ tryGCPromise(webView, done); });
	}

	TEST(AsyncFunction, Promise)
	{
	auto webView = adoptNS([[TestWKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600)]);

	NSString *functionBody = @"return new Promise(function(resolve, reject) { setTimeout(function(){ resolve(42) }, 0); })";

	bool done = false;
	[webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
	EXPECT_TRUE([result isEqualToNumber:@42]);
	done = true;
	}];
	TestWebKitAPI::Util::run(&done);
	done = false;

	functionBody = @"return new Promise(function(resolve, reject) { setTimeout(function(){ reject('Rejected!') }, 0); })";

	done = false;
	[webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
	EXPECT_NULL(result);
	EXPECT_TRUE(error != nil);
	EXPECT_TRUE([[error description] containsString:@"Rejected!"]);
	done = true;
	}];
	TestWebKitAPI::Util::run(&done);

	functionBody = @"let p = new Proxy(function(resolve, reject) { setTimeout(function() { resolve(42); }, 0); }, { }); return { then: p };";

	done = false;
	[webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
	EXPECT_TRUE([result isEqualToNumber:@42]);
	done = true;
	}];
	TestWebKitAPI::Util::run(&done);

	functionBody = @"let p = new Proxy(function(resolve, reject) { setTimeout(function() { reject('Rejected!'); }, 0); }, { }); return { then: p };";

	done = false;
	[webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
	EXPECT_NULL(result);
	EXPECT_TRUE(error != nil);
	EXPECT_TRUE([[error description] containsString:@"Rejected!"]);
	done = true;
	}];
	TestWebKitAPI::Util::run(&done);

	// Verify we can await for a promise to be resolved before returning.
	functionBody = @"var r = 0; var p = new Promise(function(fulfill, reject) { setTimeout(function(){ r = 42; fulfill(); }, 5);}); await p; return r;";

	done = false;
	[webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSNumber class]]);
	EXPECT_TRUE([result isEqualToNumber:@42]);
	done = true;
	}];
	TestWebKitAPI::Util::run(&done);

	// Returning an already resolved promise gives the value it was resolved with.
	functionBody = @"var p = new Promise(function(fulfill, reject) { setTimeout(function(){ fulfill('Fulfilled!') }, 5);}); await p; return p;";

	done = false;
	[webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSString class]]);
	EXPECT_TRUE([result isEqualToString:@"Fulfilled!"]);
	done = true;
	}];
	TestWebKitAPI::Util::run(&done);

	// Chaining thenables should work.
	functionBody = @"var p = new Promise(function (r) { r(new Promise(function (r) { r(42); })); }); await p; return 'Done';";

	done = false;
	[webView _callAsyncJavaScriptFunction:functionBody withArguments:nil inWorld:_WKContentWorld.pageContentWorld completionHandler:[&] (id result, NSError *error) {
	EXPECT_NULL(error);
	EXPECT_TRUE([result isKindOfClass:[NSString class]]);
	EXPECT_TRUE([result isEqualToString:@"Done"]);
	done = true;
	}];
	TestWebKitAPI::Util::run(&done);

	done = false;
	tryGCPromise(webView.get(), done);
	TestWebKitAPI::Util::run(&done);
	}

	}