[MERGE #4806 @rhuanjl] Implement JsGetProxyProperties API fixes #950

Merge pull request #4806 from rhuanjl:JsGetProxyProperties

Responding to issue #950

This PR:
1. Adds a JavascriptProxy::IsRevoked method to the Javascript proxy class (necessary for the below)
2. Adds a JsGetProxyProperties API to Jsrt which can:
    a) check if an object is a proxy -> set a provided bool to true/false
    b) if it is a proxy check if it's revoked
    c) if it is a revoked proxy set provided target and handler references to nullptr
    d) if it is a proxy that is not revoked provide references to it's target and handler
3. Tracks the same API through to WScriptJsrt in ch
4. Adds a test that uses the ch implementation

(Targeting 1.9 as this will assist with an issue in node-chakracore nodejs/node-chakracore#488 )

**CC:** @jackhorton @kfarnung @dilijev

bin/ChakraCore/ChakraCore.def

@@ -64,3 +64,5 @@ JsLessThanOrEqual
 JsCreateEnhancedFunction
 
 JsSetHostPromiseRejectionTracker
+
+JsGetProxyProperties

bin/ch/ChakraRtInterface.cpp

@@ -154,6 +154,7 @@ bool ChakraRTInterface::LoadChakraDll(ArgInfo* argInfo, HINSTANCE *outLibrary)
     m_jsApiHooks.pfJsrtCopyString = (JsAPIHooks::JsrtCopyString)GetChakraCoreSymbol(library, "JsCopyString");
     m_jsApiHooks.pfJsrtCreatePropertyId = (JsAPIHooks::JsrtCreatePropertyId)GetChakraCoreSymbol(library, "JsCreatePropertyId");
     m_jsApiHooks.pfJsrtCreateExternalArrayBuffer = (JsAPIHooks::JsrtCreateExternalArrayBuffer)GetChakraCoreSymbol(library, "JsCreateExternalArrayBuffer");
+    m_jsApiHooks.pfJsrtGetProxyProperties = (JsAPIHooks::JsrtGetProxyProperties)GetChakraCoreSymbol(library, "JsGetProxyProperties");
 
     m_jsApiHooks.pfJsrtTTDCreateRecordRuntime = (JsAPIHooks::JsrtTTDCreateRecordRuntimePtr)GetChakraCoreSymbol(library, "JsTTDCreateRecordRuntime");
     m_jsApiHooks.pfJsrtTTDCreateReplayRuntime = (JsAPIHooks::JsrtTTDCreateReplayRuntimePtr)GetChakraCoreSymbol(library, "JsTTDCreateReplayRuntime");

bin/ch/ChakraRtInterface.h

@@ -86,6 +86,7 @@ struct JsAPIHooks
 
     typedef JsErrorCode(WINAPI *JsrtCreateExternalArrayBuffer)(void *data, unsigned int byteLength, JsFinalizeCallback finalizeCallback, void *callbackState, JsValueRef *result);
     typedef JsErrorCode(WINAPI *JsrtCreatePropertyId)(const char *name, size_t length, JsPropertyIdRef *propertyId);
+    typedef JsErrorCode(WINAPI *JsrtGetProxyProperties)(JsValueRef object, bool* isProxy, JsValueRef* target, JsValueRef* handler);
 
     typedef JsErrorCode(WINAPI *JsrtTTDCreateRecordRuntimePtr)(JsRuntimeAttributes attributes, bool enableDebugging, size_t snapInterval, size_t snapHistoryLength, TTDOpenResourceStreamCallback openResourceStream, JsTTDWriteBytesToStreamCallback writeBytesToStream, JsTTDFlushAndCloseStreamCallback flushAndCloseStream, JsThreadServiceCallback threadService, JsRuntimeHandle *runtime);
     typedef JsErrorCode(WINAPI *JsrtTTDCreateReplayRuntimePtr)(JsRuntimeAttributes attributes, const char* infoUri, size_t infoUriCount, bool enableDebugging, TTDOpenResourceStreamCallback openResourceStream, JsTTDReadBytesFromStreamCallback readBytesFromStream, JsTTDFlushAndCloseStreamCallback flushAndCloseStream, JsThreadServiceCallback threadService, JsRuntimeHandle *runtime);
@@ -183,6 +184,7 @@ struct JsAPIHooks
     JsrtCopyString pfJsrtCopyString;
     JsrtCreatePropertyId pfJsrtCreatePropertyId;
     JsrtCreateExternalArrayBuffer pfJsrtCreateExternalArrayBuffer;
+    JsrtGetProxyProperties pfJsrtGetProxyProperties;
 
     JsrtTTDCreateRecordRuntimePtr pfJsrtTTDCreateRecordRuntime;
     JsrtTTDCreateReplayRuntimePtr pfJsrtTTDCreateReplayRuntime;
@@ -412,6 +414,7 @@ class ChakraRTInterface
     static JsErrorCode WINAPI JsCreateStringUtf16(const uint16_t *content, size_t length, JsValueRef *value) { return HOOK_JS_API(CreateStringUtf16(content, length, value)); }
     static JsErrorCode WINAPI JsCreatePropertyId(const char *name, size_t length, JsPropertyIdRef *propertyId) { return HOOK_JS_API(CreatePropertyId(name, length, propertyId)); }
     static JsErrorCode WINAPI JsCreateExternalArrayBuffer(void *data, unsigned int byteLength, JsFinalizeCallback finalizeCallback, void *callbackState, JsValueRef *result)  { return HOOK_JS_API(CreateExternalArrayBuffer(data, byteLength, finalizeCallback, callbackState, result)); }
+    static JsErrorCode WINAPI JsGetProxyProperties(JsValueRef object, bool* isProxy, JsValueRef* target, JsValueRef* handler)  { return HOOK_JS_API(GetProxyProperties(object, isProxy, target, handler)); }
 };
 
 class AutoRestoreContext

bin/ch/WScriptJsrt.cpp

@@ -859,6 +859,7 @@ bool WScriptJsrt::Initialize()
     IfFalseGo(WScriptJsrt::InstallObjectsOnObject(wscript, "LoadTextFile", LoadTextFileCallback));
     IfFalseGo(WScriptJsrt::InstallObjectsOnObject(wscript, "Flag", FlagCallback));
     IfFalseGo(WScriptJsrt::InstallObjectsOnObject(wscript, "RegisterModuleSource", RegisterModuleSourceCallback));
+    IfFalseGo(WScriptJsrt::InstallObjectsOnObject(wscript, "GetProxyProperties", GetProxyPropertiesCallback));
 
     // ToDo Remove
     IfFalseGo(WScriptJsrt::InstallObjectsOnObject(wscript, "Edit", EmptyCallback));
@@ -1371,6 +1372,57 @@ JsValueRef __stdcall WScriptJsrt::SleepCallback(JsValueRef callee, bool isConstr
     return returnValue;
 }
 
+JsValueRef __stdcall WScriptJsrt::GetProxyPropertiesCallback(JsValueRef callee, bool isConstructCall, JsValueRef *arguments, unsigned short argumentCount, void *callbackState)
+{
+    HRESULT hr = E_FAIL;
+    JsValueRef returnValue = JS_INVALID_REFERENCE;
+    JsValueRef undefined = JS_INVALID_REFERENCE;
+    JsErrorCode errorCode = JsNoError;
+
+    IfJsrtErrorSetGo(ChakraRTInterface::JsGetUndefinedValue(&undefined));
+
+    returnValue = undefined;
+
+    if (argumentCount > 1)
+    {
+        bool isProxy = false;
+        JsValueRef target;
+        JsValueRef handler;
+        IfJsrtErrorSetGo(ChakraRTInterface::JsGetProxyProperties(arguments[1], &isProxy, &target, &handler));
+
+        if (isProxy)
+        {
+            JsPropertyIdRef targetProperty;
+            JsPropertyIdRef handlerProperty;
+            JsPropertyIdRef revokedProperty;
+
+            IfJsrtErrorSetGo(CreatePropertyIdFromString("target", &targetProperty));
+            IfJsrtErrorSetGo(CreatePropertyIdFromString("handler", &handlerProperty));
+            IfJsrtErrorSetGo(CreatePropertyIdFromString("revoked", &revokedProperty));
+            IfJsrtErrorSetGo(ChakraRTInterface::JsCreateObject(&returnValue));
+
+            JsValueRef revoked = JS_INVALID_REFERENCE;
+
+            if (target == JS_INVALID_REFERENCE)
+            {
+                IfJsrtErrorSetGo(ChakraRTInterface::JsGetTrueValue(&revoked));
+                target = undefined;
+                handler = undefined;
+            }
+            else
+            {
+                IfJsrtErrorSetGo(ChakraRTInterface::JsGetFalseValue(&revoked));
+            }
+
+            IfJsrtErrorSetGo(ChakraRTInterface::JsSetProperty(returnValue, handlerProperty, handler, true));
+            IfJsrtErrorSetGo(ChakraRTInterface::JsSetProperty(returnValue, targetProperty, target, true));
+            IfJsrtErrorSetGo(ChakraRTInterface::JsSetProperty(returnValue, revokedProperty, revoked, true));
+        }
+    }
+Error:
+    return returnValue;
+}
+
 bool WScriptJsrt::PrintException(LPCSTR fileName, JsErrorCode jsErrorCode)
 {
     LPCWSTR errorTypeString = ConvertErrorCodeToMessage(jsErrorCode);

bin/ch/WScriptJsrt.h

@@ -129,6 +129,7 @@ class WScriptJsrt
     static JsValueRef CALLBACK GetReportCallback(JsValueRef callee, bool isConstructCall, JsValueRef *arguments, unsigned short argumentCount, void *callbackState);
     static JsValueRef CALLBACK LeavingCallback(JsValueRef callee, bool isConstructCall, JsValueRef *arguments, unsigned short argumentCount, void *callbackState);
     static JsValueRef CALLBACK SleepCallback(JsValueRef callee, bool isConstructCall, JsValueRef *arguments, unsigned short argumentCount, void *callbackState);
+    static JsValueRef CALLBACK GetProxyPropertiesCallback(JsValueRef callee, bool isConstructCall, JsValueRef *arguments, unsigned short argumentCount, void *callbackState);
 
     static JsErrorCode FetchImportedModuleHelper(JsModuleRecord referencingModule, JsValueRef specifier, __out JsModuleRecord* dependentModuleRecord, LPCSTR refdir = nullptr);
 

lib/Jsrt/ChakraCore.h

@@ -1035,5 +1035,33 @@ CHAKRA_API
     JsSetHostPromiseRejectionTracker(
         _In_ JsHostPromiseRejectionTrackerCallback promiseRejectionTrackerCallback, 
         _In_opt_ void *callbackState);
+
+/// <summary>
+///     Determines if a provided object is a JavscriptProxy Object and
+///     provides references to a Proxy's target and handler.
+/// </summary>
+/// <remarks>
+///     Requires an active script context.
+///     If object is not a Proxy object the target and handler parameters are not touched.
+///     If nullptr is supplied for target or handler the function returns after
+///     setting the isProxy value.
+///     If the object is a revoked Proxy target and handler are set to JS_INVALID_REFERENCE.
+///     If it is a Proxy object that has not been revoked target and handler are set to the
+///     the object's target and handler.
+/// </remarks>
+/// <param name="object">The object that may be a Proxy.</param>
+/// <param name="isProxy">Pointer to a Boolean - is the object a proxy?</param>
+/// <param name="target">Pointer to a JsValueRef - the object's target.</param>
+/// <param name="handler">Pointer to a JsValueRef - the object's handler.</param>
+/// <returns>
+///     The code <c>JsNoError</c> if the operation succeeded, a failure code otherwise.
+/// </returns>
+CHAKRA_API
+    JsGetProxyProperties(
+        _In_ JsValueRef object,
+        _Out_ bool* isProxy,
+        _Out_opt_ JsValueRef* target,
+        _Out_opt_ JsValueRef* handler);
+
 #endif // _CHAKRACOREBUILD
 #endif // _CHAKRACORE_H_

lib/Jsrt/Jsrt.cpp

@@ -5329,4 +5329,45 @@ CHAKRA_API JsSetHostPromiseRejectionTracker(_In_ JsHostPromiseRejectionTrackerCa
     /*allowInObjectBeforeCollectCallback*/true);
 }
 
+CHAKRA_API JsGetProxyProperties (_In_ JsValueRef object, _Out_ bool* isProxy, _Out_opt_ JsValueRef* target, _Out_opt_ JsValueRef* handler)
+{
+    return ContextAPINoScriptWrapper_NoRecord([&](Js::ScriptContext * scriptContext) -> JsErrorCode {
+        VALIDATE_INCOMING_REFERENCE(object, scriptContext);
+        PARAM_NOT_NULL(isProxy);
+
+        if (target != nullptr)
+        {
+            *target = JS_INVALID_REFERENCE;
+        }
+
+        if (handler != nullptr)
+        {
+            *handler = JS_INVALID_REFERENCE;
+        }
+
+        *isProxy = Js::JavascriptProxy::Is(object);
+
+        if (!*isProxy)
+        {
+            return JsNoError;
+        }
+
+        Js::JavascriptProxy* proxy = Js::JavascriptProxy::UnsafeFromVar(object);
+        bool revoked = proxy->IsRevoked();
+
+        if (target != nullptr && !revoked)
+        {
+            *target = static_cast<JsValueRef>(proxy->GetTarget());
+        }
+
+        if (handler != nullptr && !revoked)
+        {
+            *handler = static_cast<JsValueRef>(proxy->GetHandler());
+        }
+
+        return JsNoError;
+    },
+    /*allowInObjectBeforeCollectCallback*/true);
+}
+
 #endif // _CHAKRACOREBUILD

lib/Runtime/Library/JavascriptProxy.cpp

@@ -16,6 +16,11 @@ namespace Js
         return JavascriptOperators::GetTypeId(obj) == TypeIds_Proxy;
     }
 
+    bool JavascriptProxy::IsRevoked() const
+    {
+        return (target == nullptr);
+    }
+
     RecyclableObject* JavascriptProxy::GetTarget()
     {
         if (target == nullptr)

lib/Runtime/Library/JavascriptProxy.h

@@ -154,6 +154,7 @@ namespace Js
         virtual RecyclableObject* ToObject(ScriptContext * requestContext) override;
         virtual Var GetTypeOfString(ScriptContext* requestContext) override;
 
+        bool IsRevoked() const;
         BOOL SetPropertyTrap(Var receiver, SetPropertyTrapKind setPropertyTrapKind, PropertyId propertyId, Var newValue, ScriptContext* requestContext, BOOL skipPrototypeCheck = FALSE);
         BOOL SetPropertyTrap(Var receiver, SetPropertyTrapKind setPropertyTrapKind, Js::JavascriptString * propertyString, Var newValue, ScriptContext* requestContext);
 

test/es6/ProxyPropertiesAPI.js

@@ -0,0 +1,90 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+WScript.LoadScriptFile("..\\UnitTestFramework\\UnitTestFramework.js");
+
+let tests = [
+   {
+       name: "GetProxyProperties: no argugments",
+       body: function () {
+           let properties = WScript.GetProxyProperties();
+           assert.isUndefined(properties, "ProxyProperties of nothing should be undefined.");
+        }
+   },
+   {
+        name: "GetProxyProperties: non-proxy arguments",
+        body: function () {
+            let properties = WScript.GetProxyProperties(undefined);
+            assert.isUndefined(properties, "ProxyProperties of undefined should be undefined.");
+            properties = WScript.GetProxyProperties(1);
+            assert.isUndefined(properties, "ProxyProperties of number should be undefined.");
+            properties = WScript.GetProxyProperties({});
+            assert.isUndefined(properties, "ProxyProperties of non-proxy object should be undefined.");
+        }
+    },
+    {
+        name: "GetProxyProperties: revocable Proxy",
+        body: function () {
+            let revocable = Proxy.revocable({someProperty: true, otherProperty: false}, {otherProperty: true, newProperty: 5});
+            let proxy = revocable.proxy;
+            let properties = WScript.GetProxyProperties(proxy);
+
+            let names = Object.getOwnPropertyNames(properties);
+            assert.areEqual(names.length, 3, "proxy properties names should have length 3.");
+            assert.isTrue(names.includes("target"));
+            assert.isTrue(names.includes("handler"));
+            assert.isTrue(names.includes("revoked"));
+            assert.isFalse(properties.revoked, "Revoked bool should be false.");
+
+            names = Object.getOwnPropertyNames(properties.target);
+            assert.areEqual(names.length, 2, "proxy properties target names should have length 2.");
+            assert.areEqual(properties.target.someProperty, true);
+            assert.areEqual(properties.target.otherProperty, false);
+
+            names = Object.getOwnPropertyNames(properties.handler);
+            assert.areEqual(names.length, 2, "proxy properties handler names should have length 2.");
+            assert.areEqual(properties.handler.newProperty, 5);
+            assert.areEqual(properties.handler.otherProperty, true);
+
+            revocable.revoke();
+            properties = WScript.GetProxyProperties(proxy);
+
+            names = Object.getOwnPropertyNames(properties);
+            assert.areEqual(names.length, 3, "proxy properties names for revokes proxy should have length 3.");
+            assert.isTrue(names.includes("target"));
+            assert.isTrue(names.includes("handler"));
+            assert.isTrue(properties.revoked, "Revoked bool should be true.");
+
+            assert.isUndefined(properties.target, "Target of revoked proxy should be undefined.");
+            assert.isUndefined(properties.handler, "Handler of revoked proxy should be undefined.");
+        }
+    },
+    {
+        name: "GetProxyProperties: normal Proxy",
+        body: function () {
+            let proxy = new Proxy({someProperty: true, otherProperty: false}, {otherProperty: true, newProperty: 5});
+            let properties = WScript.GetProxyProperties(proxy);
+
+            let names = Object.getOwnPropertyNames(properties);
+            assert.areEqual(names.length, 3, "proxy properties names should have length 3");
+            assert.isTrue(names.includes("target"));
+            assert.isTrue(names.includes("handler"));
+            assert.isTrue(names.includes("revoked"));
+            assert.isFalse(properties.revoked, "Revoked bool should be false.");
+
+            names = Object.getOwnPropertyNames(properties.target);
+            assert.areEqual(names.length, 2, "proxy properties target names should have length 2");
+            assert.areEqual(properties.target.someProperty, true);
+            assert.areEqual(properties.target.otherProperty, false);
+
+            names = Object.getOwnPropertyNames(properties.handler);
+            assert.areEqual(names.length, 2, "proxy properties handler names should have length 2");
+            assert.areEqual(properties.handler.newProperty, 5);
+            assert.areEqual(properties.handler.otherProperty, true);
+        }
+    }
+];
+
+testRunner.runTests(tests, { verbose: WScript.Arguments[0] != "summary" });

test/es6/rlexe.xml

@@ -715,6 +715,13 @@
       <compile-flags>-args summary -endargs</compile-flags>
     </default>
   </test>
+  <test>
+    <default>
+      <files>ProxyPropertiesAPI.js</files>
+      <compile-flags>-args summary -endargs</compile-flags>
+      <tags>exclude_jshost</tags>
+    </default>
+  </test>
   <test>
     <default>
       <files>proxybugs.js</files>