LayoutTests/js/script-tests/prototype-assignment.js - WebKit - Git at Google

 //@ runFTLNoCJIT

 // This test suite compares the behavior of setting the prototype on various values
 // (using Object.setPrototypeOf(), obj.__proto__ assignment, and Reflect.setPrototypeOf())
 // against what is specified in the ES spec.  The expected behavior specified according
 // to the spec is expressed in expectationsForObjectSetPrototypeOf,
 // expectationsForSetUnderscoreProto, and expectationsForReflectSetPrototypeOf.


 var inBrowser = (typeof window != "undefined");

 // Test configuration options:
 var verbose = false;
 var maxIterations = 1;
 var throwOnEachError = true;

 var testUndefined = true;
 var testNull = true;
 var testTrue = true;
 var testFalse = true;
 var testNumbers = true;
 var testString = true;
 var testSymbol = true;
 var testObject = true;
 var testGlobal = true;
 var testWindowProtos = inBrowser;

 //====================================================================================
 // Error messages:

 if (inBrowser) {
     let userAgent = navigator.userAgent;
     if (userAgent.match(/ Chrome\/[0-9]+/)) engine = "chrome";
     else if (userAgent.match(/ Firefox\/[0-9]+/)) engine = "default";
     else engine = "safari";
 } else
     engine = "jsc";

 // Set default error messages and then override with engine specific ones below.
 DefaultTypeError = "TypeError: ";
 CannotSetPrototypeOfImmutablePrototypeObject = DefaultTypeError;
 CannotSetPrototypeOfThisObject = DefaultTypeError;
 CannotSetPrototypeOfUndefinedOrNull = DefaultTypeError;
 CannotSetPrototypeOfNonObject = DefaultTypeError;
 PrototypeValueCanOnlyBeAnObjectOrNull = DefaultTypeError;
 ObjectProtoCalledOnNullOrUndefinedError = DefaultTypeError;
 ReflectSetPrototypeOfRequiresTheFirstArgumentBeAnObject = DefaultTypeError;
 ReflectSetPrototypeOfRequiresTheSecondArgumentBeAnObjectOrNull = DefaultTypeError;

 if (engine == "jsc" || engine === "safari") {
     CannotSetPrototypeOfImmutablePrototypeObject = "TypeError: Cannot set prototype of immutable prototype object";
     CannotSetPrototypeOfThisObject = "TypeError: Cannot set prototype of this object";
     CannotSetPrototypeOfUndefinedOrNull = "TypeError: Cannot set prototype of undefined or null";
     CannotSetPrototypeOfNonObject = "TypeError: Cannot set prototype of non-object";
     PrototypeValueCanOnlyBeAnObjectOrNull = "TypeError: Prototype value can only be an object or null";
     ObjectProtoCalledOnNullOrUndefinedError = "TypeError: Object.prototype.__proto__ called on null or undefined";
     ReflectSetPrototypeOfRequiresTheFirstArgumentBeAnObject = "TypeError: Reflect.setPrototypeOf requires the first argument be an object";
     ReflectSetPrototypeOfRequiresTheSecondArgumentBeAnObjectOrNull = "TypeError: Reflect.setPrototypeOf requires the second argument be either an object or null";
 } else if (engine === "chrome") {
     CannotSetPrototypeOfImmutablePrototypeObject = "TypeError: Immutable prototype object ";
 }

 //====================================================================================
 // Utility functions:

 if (inBrowser)
     print = console.log;

 function reportError(errorMessage) {
     if (throwOnEachError)
         throw errorMessage;
     else
         print(errorMessage);
 }

 function shouldEqual(testID, resultType, actual, expected) {
     if (actual != expected)
         reportError("ERROR in " + resultType
             + ": expect " + stringify(expected) + ", actual " + stringify(actual)
             + " in test: " + testID.signature + " on iteration " + testID.iteration);
 }

 function shouldThrow(testID, resultType, actual, expected) {
     let actualStr = "" + actual;
     if (!actualStr.startsWith(expected))
         reportError("ERROR in " + resultType
             + ": expect " + expected + ", actual " + actual
             + " in test: " + testID.signature + " on iteration " + testID.iteration);
 }

 function stringify(value) {
     if (typeof value == "string") return '"' + value + '"';
     if (typeof value == "symbol") return value.toString();

     if (value === origGlobalProto) return "origGlobalProto";
     if (value === origObjectProto) return "origObjectProto";
     if (value === newObjectProto) return "newObjectProto";
     if (value === proxyObject) return "proxyObject";

     if (value === null) return "null";
     if (typeof value == "object") return "object";
     return "" + value;
 }

 function makeTestID(index, iteration, targetName, protoToSet, protoSetter, expected) {
     let testID = {};
     testID.signature = "[" + index + "] "
         + protoSetter.actionName + "|"
         + targetName + "|"
         + stringify(protoToSet) + "|"
         + stringify(expected.result) + "|"
         + stringify(expected.proto) + "|"
         + stringify(expected.exception);
     testID.iteration = iteration;
     return testID;
 }

 //====================================================================================
 // Functions to express the expectations of the ES specification:

 function doInternalSetPrototypeOf(result, target, origProto, newProto) {
     if (!target.setPrototypeOf) {
         result.success = true;
         result.exception = undefined;
         return;
     }
     target.setPrototypeOf(result, origProto, newProto);
 }

 // 9.1.2.1 OrdinarySetPrototypeOf ( O, V )
 // https://tc39.github.io/ecma262/#sec-ordinarysetprototypeof
 function ordinarySetPrototypeOf(result, currentProto, newProto) {
     // 9.1.2.1-4 If SameValue(V, current) is true, return true.
     if (newProto === currentProto) {
         result.success = true;
         return;
     }
     // 9.1.2.1-5 [extensibility check not tested here]
     // 9.1.2.1-8 [cycle check not tested here]
     result.success = true;
 }

 // 9.4.7.2 SetImmutablePrototype ( O, V )
 // https://tc39.github.io/ecma262/#sec-set-immutable-prototype
 function setImmutablePrototype(result, currentProto, newProto) {
     if (newProto === currentProto) {
         result.success = true;
         return;
     }
     result.success = false;
     result.exception = CannotSetPrototypeOfImmutablePrototypeObject;
 }


 var count = 0;
 function initSetterExpectation(target, newProto) {
     var targetValue = target.value();
     var origProto = undefined;
     if (targetValue != null && targetValue != undefined)
         origProto = targetValue.__proto__; // Default to old proto.

     var expected = {};
     expected.targetValue = targetValue;
     expected.origProto = origProto;
     expected.exception = undefined;
     expected.proto = origProto;
     expected.result = undefined;

     return expected;
 }

 // 19.1.2.21 Object.setPrototypeOf ( O, proto )
 // https://tc39.github.io/ecma262/#sec-object.setprototypeof
 function objectSetPrototypeOf(target, newProto) {
     let expected = initSetterExpectation(target, newProto);
     var targetValue = expected.targetValue;
     var origProto = expected.origProto;

     function throwIfNoExceptionPending(e) {
         if (!expected.exception)
             expected.exception = e;
     }

     // 19.1.2.21-1 Let O be ? RequireObjectCoercible(O).
     if (targetValue == undefined || targetValue == null)
         throwIfNoExceptionPending(CannotSetPrototypeOfUndefinedOrNull);

     // 19.1.2.21-2 If Type(proto) is neither Object nor Null, throw a TypeError exception.
     if (typeof newProto != "object")
         throwIfNoExceptionPending(PrototypeValueCanOnlyBeAnObjectOrNull);

     // 19.1.2.21-3 If Type(O) is not Object, return O.
     else if (typeof targetValue != "object")
         expected.result = targetValue;

     // 19.1.2.21-4 Let status be ? O.[[SetPrototypeOf]](proto).
     else {
         // 19.1.2.21-5 If status is false, throw a TypeError exception.
         let result = {};
         doInternalSetPrototypeOf(result, target, origProto, newProto);
         if (result.success)
             expected.proto = newProto;
         else
             throwIfNoExceptionPending(result.exception);

         // 19.1.2.21-6 Return O.
         expected.result = targetValue;
     }

     return expected;
 }
 objectSetPrototypeOf.action = (obj, newProto) => Object.setPrototypeOf(obj, newProto);
 objectSetPrototypeOf.actionName = "Object.setPrototypeOf";


 // B.2.2.1.2 set Object.prototype.__proto__
 // https://tc39.github.io/ecma262/#sec-set-object.prototype.__proto__
 function setUnderscoreProto(target, newProto) {
     let expected = initSetterExpectation(target, newProto);
     var targetValue = expected.targetValue;
     var origProto = expected.origProto;

     function throwIfNoExceptionPending(e) {
         if (!expected.exception)
             expected.exception = e;
     }

     // B.2.2.1.2-1 Let O be ? RequireObjectCoercible(this value).
     if (targetValue == undefined || targetValue == null)
         throwIfNoExceptionPending(DefaultTypeError);

     // B.2.2.1.2-2 If Type(proto) is neither Object nor Null, return undefined.
     if (typeof newProto != "object")
         expected.result = undefined;

     // B.2.2.1.2-3 If Type(O) is not Object, return undefined.
     else if (typeof targetValue != "object")
         expected.result = undefined;

     // B.2.2.1.2-4 Let status be ? O.[[SetPrototypeOf]](proto).
     else {
         // B.2.2.1.2-5 If status is false, throw a TypeError exception.
         let result = {};
         doInternalSetPrototypeOf(result, target, origProto, newProto);
         if (result.success)
             expected.proto = newProto;
         else
             throwIfNoExceptionPending(result.exception);

         // B.2.2.1.2-6 Return undefined.
         expected.result = undefined;
     }

     // Override the result to be the newProto value because the statement obj.__proto__ = value
     // will produce the rhs value, not the result of the obj.__proto__ setter.
     expected.result = newProto;
     return expected;
 }
 setUnderscoreProto.action = (obj, newProto) => (obj.__proto__ = newProto);
 setUnderscoreProto.actionName = "obj.__proto__";


 // 26.1.13 Reflect.setPrototypeOf ( target, proto )
 // https://tc39.github.io/ecma262/#sec-reflect.setprototypeof
 // function expectationsForReflectSetPrototypeOf(target, newProto, targetExpectation) {
 function reflectSetPrototypeOf(target, newProto) {
     let expected = initSetterExpectation(target, newProto);
     var targetValue = expected.targetValue;
     var origProto = expected.origProto;

     function throwIfNoExceptionPending(e) {
         if (!expected.exception)
             expected.exception = e;
     }

     // 26.1.13-1 If Type(target) is not Object, throw a TypeError exception.
     if (targetValue === null || typeof targetValue != "object")
         throwIfNoExceptionPending(ReflectSetPrototypeOfRequiresTheFirstArgumentBeAnObject);

     // 26.1.13-2 If Type(proto) is not Object and proto is not null, throw a TypeError exception.
     if (typeof newProto != "object")
         throwIfNoExceptionPending(ReflectSetPrototypeOfRequiresTheSecondArgumentBeAnObjectOrNull);

     // 26.1.13-3 Return ? target.[[SetPrototypeOf]](proto).
     let result = {};
     doInternalSetPrototypeOf(result, target, origProto, newProto);
     expected.result = result.success;
     if (result.success)
         expected.proto = newProto;

     return expected;
 }
 reflectSetPrototypeOf.action = (obj, newProto) => Reflect.setPrototypeOf(obj, newProto);
 reflectSetPrototypeOf.actionName = "Reflect.setPrototypeOf";


 //====================================================================================
 // Test Data:

 var global = this;
 var origGlobalProto = global.__proto__;
 var origObjectProto = {}.__proto__;
 var proxyObject = new Proxy({ }, {
     setPrototypeOf(target, value) {
         throw "Thrown from proxy";
     }
 });
 var newObjectProto = { toString() { return "newObjectProto"; } };

 var targets = [];

 if (this.testUndefined) targets.push({ name: "undefined", value: () => undefined });
 if (this.testNull)      targets.push({ name: "null", value: () => null });
 if (this.testTrue)     targets.push({ name: "true", value: () => true });
 if (this.testFalse)        targets.push({ name: "false", value: () => false });

 if (this.testNumbers) {
     targets.push({ name: "0", value: () => 0 });
     targets.push({ name: "11", value: () => 11 });
     targets.push({ name: "123.456", value: () => 123.456 });
 }

 if (this.testString)    targets.push({ name: '"doh"', value: () => "doh" });
 if (this.testSymbol)    targets.push({ name: "Symbol(doh)", value: () => Symbol("doh") });

 if (this.testObject) {
     targets.push({
         name: "{}",
         value: () => {},
         setPrototypeOf: ordinarySetPrototypeOf
     });
     targets.push({
         name: "{}.__proto__",
         value: () => origObjectProto,
         setPrototypeOf: setImmutablePrototype
     });
 }
 if (this.testGlobal) {
     targets.push({
         name: inBrowser ? "window" : "global",
         value: () => global,
         setPrototypeOf: setImmutablePrototype
     });
 }
 if (this.testWindowProtos) {
     if (inBrowser) {
         let depth = 1;
         let proto = window.__proto__;
         while (proto) {
             let name = "window";
             for (var i = 0; i < depth; i++)
                 name += ".__proto__";

             let currentProto = proto;
             targets.push({
                 name: name,
                 value: () => currentProto,
                 setPrototypeOf: setImmutablePrototype
             });

             proto = proto.__proto__;
             depth++;
         }
     }
 }


 var newProtos = [
     undefined,
     null,
     true,
     false,
     0,
     11,
     123.456,
     "doh",
     Symbol("doh"),
     {},
     origObjectProto,
     origGlobalProto,
     newObjectProto
 ];

 var protoSetters = [
     objectSetPrototypeOf,
     setUnderscoreProto,
     reflectSetPrototypeOf,
 ];


 //====================================================================================
 // Test driver functions:

 function test(testID, targetValue, newProto, setterAction, expected) {
     let exception = undefined;
     let result = undefined;
     try {
         result = setterAction(targetValue, newProto);
     } catch (e) {
         exception = e;
     }
     shouldThrow(testID, "exception", exception, expected.exception);
     if (!expected.exception) {
         shouldEqual(testID, "__proto__", targetValue.__proto__, expected.proto);
         shouldEqual(testID, "result", result, expected.result);
     }
 }

 function runTests() {
     let testIndex = 0;
     for (protoSetter of protoSetters) {
         for (target of targets) {
             for (newProto of newProtos) {
                 let currentTestIndex = testIndex++;
                 for (var i = 0; i < maxIterations; i++) {
                     let expected = protoSetter(target, newProto);
                     let targetValue = expected.targetValue;

                     let testID = makeTestID(currentTestIndex, i, target.name, newProto, protoSetter, expected);
                     if (verbose && i == 0)
                         print("test: " + testID.signature);

                     test(testID, targetValue, newProto, protoSetter.action, expected);
                 }
             }
         }
     }
 }

 runTests();
	//@ runFTLNoCJIT

	// This test suite compares the behavior of setting the prototype on various values
	// (using Object.setPrototypeOf(), obj.__proto__ assignment, and Reflect.setPrototypeOf())
	// against what is specified in the ES spec. The expected behavior specified according
	// to the spec is expressed in expectationsForObjectSetPrototypeOf,
	// expectationsForSetUnderscoreProto, and expectationsForReflectSetPrototypeOf.


	var inBrowser = (typeof window != "undefined");

	// Test configuration options:
	var verbose = false;
	var maxIterations = 1;
	var throwOnEachError = true;

	var testUndefined = true;
	var testNull = true;
	var testTrue = true;
	var testFalse = true;
	var testNumbers = true;
	var testString = true;
	var testSymbol = true;
	var testObject = true;
	var testGlobal = true;
	var testWindowProtos = inBrowser;

	//====================================================================================
	// Error messages:

	if (inBrowser) {
	let userAgent = navigator.userAgent;
	if (userAgent.match(/ Chrome\/[0-9]+/)) engine = "chrome";
	else if (userAgent.match(/ Firefox\/[0-9]+/)) engine = "default";
	else engine = "safari";
	} else
	engine = "jsc";

	// Set default error messages and then override with engine specific ones below.
	DefaultTypeError = "TypeError: ";
	CannotSetPrototypeOfImmutablePrototypeObject = DefaultTypeError;
	CannotSetPrototypeOfThisObject = DefaultTypeError;
	CannotSetPrototypeOfUndefinedOrNull = DefaultTypeError;
	CannotSetPrototypeOfNonObject = DefaultTypeError;
	PrototypeValueCanOnlyBeAnObjectOrNull = DefaultTypeError;
	ObjectProtoCalledOnNullOrUndefinedError = DefaultTypeError;
	ReflectSetPrototypeOfRequiresTheFirstArgumentBeAnObject = DefaultTypeError;
	ReflectSetPrototypeOfRequiresTheSecondArgumentBeAnObjectOrNull = DefaultTypeError;

	if (engine == "jsc" \|\| engine === "safari") {
	CannotSetPrototypeOfImmutablePrototypeObject = "TypeError: Cannot set prototype of immutable prototype object";
	CannotSetPrototypeOfThisObject = "TypeError: Cannot set prototype of this object";
	CannotSetPrototypeOfUndefinedOrNull = "TypeError: Cannot set prototype of undefined or null";
	CannotSetPrototypeOfNonObject = "TypeError: Cannot set prototype of non-object";
	PrototypeValueCanOnlyBeAnObjectOrNull = "TypeError: Prototype value can only be an object or null";
	ObjectProtoCalledOnNullOrUndefinedError = "TypeError: Object.prototype.__proto__ called on null or undefined";
	ReflectSetPrototypeOfRequiresTheFirstArgumentBeAnObject = "TypeError: Reflect.setPrototypeOf requires the first argument be an object";
	ReflectSetPrototypeOfRequiresTheSecondArgumentBeAnObjectOrNull = "TypeError: Reflect.setPrototypeOf requires the second argument be either an object or null";
	} else if (engine === "chrome") {
	CannotSetPrototypeOfImmutablePrototypeObject = "TypeError: Immutable prototype object ";
	}

	//====================================================================================
	// Utility functions:

	if (inBrowser)
	print = console.log;

	function reportError(errorMessage) {
	if (throwOnEachError)
	throw errorMessage;
	else
	print(errorMessage);
	}

	function shouldEqual(testID, resultType, actual, expected) {
	if (actual != expected)
	reportError("ERROR in " + resultType
	+ ": expect " + stringify(expected) + ", actual " + stringify(actual)
	+ " in test: " + testID.signature + " on iteration " + testID.iteration);
	}

	function shouldThrow(testID, resultType, actual, expected) {
	let actualStr = "" + actual;
	if (!actualStr.startsWith(expected))
	reportError("ERROR in " + resultType
	+ ": expect " + expected + ", actual " + actual
	+ " in test: " + testID.signature + " on iteration " + testID.iteration);
	}

	function stringify(value) {
	if (typeof value == "string") return '"' + value + '"';
	if (typeof value == "symbol") return value.toString();

	if (value === origGlobalProto) return "origGlobalProto";
	if (value === origObjectProto) return "origObjectProto";
	if (value === newObjectProto) return "newObjectProto";
	if (value === proxyObject) return "proxyObject";

	if (value === null) return "null";
	if (typeof value == "object") return "object";
	return "" + value;
	}

	function makeTestID(index, iteration, targetName, protoToSet, protoSetter, expected) {
	let testID = {};
	testID.signature = "[" + index + "] "
	+ protoSetter.actionName + "\|"
	+ targetName + "\|"
	+ stringify(protoToSet) + "\|"
	+ stringify(expected.result) + "\|"
	+ stringify(expected.proto) + "\|"
	+ stringify(expected.exception);
	testID.iteration = iteration;
	return testID;
	}

	//====================================================================================
	// Functions to express the expectations of the ES specification:

	function doInternalSetPrototypeOf(result, target, origProto, newProto) {
	if (!target.setPrototypeOf) {
	result.success = true;
	result.exception = undefined;
	return;
	}
	target.setPrototypeOf(result, origProto, newProto);
	}

	// 9.1.2.1 OrdinarySetPrototypeOf ( O, V )
	// https://tc39.github.io/ecma262/#sec-ordinarysetprototypeof
	function ordinarySetPrototypeOf(result, currentProto, newProto) {
	// 9.1.2.1-4 If SameValue(V, current) is true, return true.
	if (newProto === currentProto) {
	result.success = true;
	return;
	}
	// 9.1.2.1-5 [extensibility check not tested here]
	// 9.1.2.1-8 [cycle check not tested here]
	result.success = true;
	}

	// 9.4.7.2 SetImmutablePrototype ( O, V )
	// https://tc39.github.io/ecma262/#sec-set-immutable-prototype
	function setImmutablePrototype(result, currentProto, newProto) {
	if (newProto === currentProto) {
	result.success = true;
	return;
	}
	result.success = false;
	result.exception = CannotSetPrototypeOfImmutablePrototypeObject;
	}


	var count = 0;
	function initSetterExpectation(target, newProto) {
	var targetValue = target.value();
	var origProto = undefined;
	if (targetValue != null && targetValue != undefined)
	origProto = targetValue.__proto__; // Default to old proto.

	var expected = {};
	expected.targetValue = targetValue;
	expected.origProto = origProto;
	expected.exception = undefined;
	expected.proto = origProto;
	expected.result = undefined;

	return expected;
	}

	// 19.1.2.21 Object.setPrototypeOf ( O, proto )
	// https://tc39.github.io/ecma262/#sec-object.setprototypeof
	function objectSetPrototypeOf(target, newProto) {
	let expected = initSetterExpectation(target, newProto);
	var targetValue = expected.targetValue;
	var origProto = expected.origProto;

	function throwIfNoExceptionPending(e) {
	if (!expected.exception)
	expected.exception = e;
	}

	// 19.1.2.21-1 Let O be ? RequireObjectCoercible(O).
	if (targetValue == undefined \|\| targetValue == null)
	throwIfNoExceptionPending(CannotSetPrototypeOfUndefinedOrNull);

	// 19.1.2.21-2 If Type(proto) is neither Object nor Null, throw a TypeError exception.
	if (typeof newProto != "object")
	throwIfNoExceptionPending(PrototypeValueCanOnlyBeAnObjectOrNull);

	// 19.1.2.21-3 If Type(O) is not Object, return O.
	else if (typeof targetValue != "object")
	expected.result = targetValue;

	// 19.1.2.21-4 Let status be ? O.[[SetPrototypeOf]](proto).
	else {
	// 19.1.2.21-5 If status is false, throw a TypeError exception.
	let result = {};
	doInternalSetPrototypeOf(result, target, origProto, newProto);
	if (result.success)
	expected.proto = newProto;
	else
	throwIfNoExceptionPending(result.exception);

	// 19.1.2.21-6 Return O.
	expected.result = targetValue;
	}

	return expected;
	}
	objectSetPrototypeOf.action = (obj, newProto) => Object.setPrototypeOf(obj, newProto);
	objectSetPrototypeOf.actionName = "Object.setPrototypeOf";


	// B.2.2.1.2 set Object.prototype.__proto__
	// https://tc39.github.io/ecma262/#sec-set-object.prototype.__proto__
	function setUnderscoreProto(target, newProto) {
	let expected = initSetterExpectation(target, newProto);
	var targetValue = expected.targetValue;
	var origProto = expected.origProto;

	function throwIfNoExceptionPending(e) {
	if (!expected.exception)
	expected.exception = e;
	}

	// B.2.2.1.2-1 Let O be ? RequireObjectCoercible(this value).
	if (targetValue == undefined \|\| targetValue == null)
	throwIfNoExceptionPending(DefaultTypeError);

	// B.2.2.1.2-2 If Type(proto) is neither Object nor Null, return undefined.
	if (typeof newProto != "object")
	expected.result = undefined;

	// B.2.2.1.2-3 If Type(O) is not Object, return undefined.
	else if (typeof targetValue != "object")
	expected.result = undefined;

	// B.2.2.1.2-4 Let status be ? O.[[SetPrototypeOf]](proto).
	else {
	// B.2.2.1.2-5 If status is false, throw a TypeError exception.
	let result = {};
	doInternalSetPrototypeOf(result, target, origProto, newProto);
	if (result.success)
	expected.proto = newProto;
	else
	throwIfNoExceptionPending(result.exception);

	// B.2.2.1.2-6 Return undefined.
	expected.result = undefined;
	}

	// Override the result to be the newProto value because the statement obj.__proto__ = value
	// will produce the rhs value, not the result of the obj.__proto__ setter.
	expected.result = newProto;
	return expected;
	}
	setUnderscoreProto.action = (obj, newProto) => (obj.__proto__ = newProto);
	setUnderscoreProto.actionName = "obj.__proto__";


	// 26.1.13 Reflect.setPrototypeOf ( target, proto )
	// https://tc39.github.io/ecma262/#sec-reflect.setprototypeof
	// function expectationsForReflectSetPrototypeOf(target, newProto, targetExpectation) {
	function reflectSetPrototypeOf(target, newProto) {
	let expected = initSetterExpectation(target, newProto);
	var targetValue = expected.targetValue;
	var origProto = expected.origProto;

	function throwIfNoExceptionPending(e) {
	if (!expected.exception)
	expected.exception = e;
	}

	// 26.1.13-1 If Type(target) is not Object, throw a TypeError exception.
	if (targetValue === null \|\| typeof targetValue != "object")
	throwIfNoExceptionPending(ReflectSetPrototypeOfRequiresTheFirstArgumentBeAnObject);

	// 26.1.13-2 If Type(proto) is not Object and proto is not null, throw a TypeError exception.
	if (typeof newProto != "object")
	throwIfNoExceptionPending(ReflectSetPrototypeOfRequiresTheSecondArgumentBeAnObjectOrNull);

	// 26.1.13-3 Return ? target.[[SetPrototypeOf]](proto).
	let result = {};
	doInternalSetPrototypeOf(result, target, origProto, newProto);
	expected.result = result.success;
	if (result.success)
	expected.proto = newProto;

	return expected;
	}
	reflectSetPrototypeOf.action = (obj, newProto) => Reflect.setPrototypeOf(obj, newProto);
	reflectSetPrototypeOf.actionName = "Reflect.setPrototypeOf";


	//====================================================================================
	// Test Data:

	var global = this;
	var origGlobalProto = global.__proto__;
	var origObjectProto = {}.__proto__;
	var proxyObject = new Proxy({ }, {
	setPrototypeOf(target, value) {
	throw "Thrown from proxy";
	}
	});
	var newObjectProto = { toString() { return "newObjectProto"; } };

	var targets = [];

	if (this.testUndefined) targets.push({ name: "undefined", value: () => undefined });
	if (this.testNull) targets.push({ name: "null", value: () => null });
	if (this.testTrue) targets.push({ name: "true", value: () => true });
	if (this.testFalse) targets.push({ name: "false", value: () => false });

	if (this.testNumbers) {
	targets.push({ name: "0", value: () => 0 });
	targets.push({ name: "11", value: () => 11 });
	targets.push({ name: "123.456", value: () => 123.456 });
	}

	if (this.testString) targets.push({ name: '"doh"', value: () => "doh" });
	if (this.testSymbol) targets.push({ name: "Symbol(doh)", value: () => Symbol("doh") });

	if (this.testObject) {
	targets.push({
	name: "{}",
	value: () => {},
	setPrototypeOf: ordinarySetPrototypeOf
	});
	targets.push({
	name: "{}.__proto__",
	value: () => origObjectProto,
	setPrototypeOf: setImmutablePrototype
	});
	}
	if (this.testGlobal) {
	targets.push({
	name: inBrowser ? "window" : "global",
	value: () => global,
	setPrototypeOf: setImmutablePrototype
	});
	}
	if (this.testWindowProtos) {
	if (inBrowser) {
	let depth = 1;
	let proto = window.__proto__;
	while (proto) {
	let name = "window";
	for (var i = 0; i < depth; i++)
	name += ".__proto__";

	let currentProto = proto;
	targets.push({
	name: name,
	value: () => currentProto,
	setPrototypeOf: setImmutablePrototype
	});

	proto = proto.__proto__;
	depth++;
	}
	}
	}


	var newProtos = [
	undefined,
	null,
	true,
	false,
	0,
	11,
	123.456,
	"doh",
	Symbol("doh"),
	{},
	origObjectProto,
	origGlobalProto,
	newObjectProto
	];

	var protoSetters = [
	objectSetPrototypeOf,
	setUnderscoreProto,
	reflectSetPrototypeOf,
	];


	//====================================================================================
	// Test driver functions:

	function test(testID, targetValue, newProto, setterAction, expected) {
	let exception = undefined;
	let result = undefined;
	try {
	result = setterAction(targetValue, newProto);
	} catch (e) {
	exception = e;
	}
	shouldThrow(testID, "exception", exception, expected.exception);
	if (!expected.exception) {
	shouldEqual(testID, "__proto__", targetValue.__proto__, expected.proto);
	shouldEqual(testID, "result", result, expected.result);
	}
	}

	function runTests() {
	let testIndex = 0;
	for (protoSetter of protoSetters) {
	for (target of targets) {
	for (newProto of newProtos) {
	let currentTestIndex = testIndex++;
	for (var i = 0; i < maxIterations; i++) {
	let expected = protoSetter(target, newProto);
	let targetValue = expected.targetValue;

	let testID = makeTestID(currentTestIndex, i, target.name, newProto, protoSetter, expected);
	if (verbose && i == 0)
	print("test: " + testID.signature);

	test(testID, targetValue, newProto, protoSetter.action, expected);
	}
	}
	}
	}
	}

	runTests();