Groundwork for generators (#1705)

* basic constructor, prototype and instance,
* update some packages
* remove null value from completion which violates NRT promises

Directory.Packages.props

@@ -4,31 +4,31 @@
     <CentralPackageTransitivePinningEnabled>false</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="BenchmarkDotNet" Version="0.13.10" />
+    <PackageVersion Include="BenchmarkDotNet" Version="0.13.11" />
     <PackageVersion Include="Esprima" Version="3.0.2" />
     <PackageVersion Include="Flurl.Http.Signed" Version="3.2.4" />
     <PackageVersion Include="Jurassic" Version="3.2.7" />
-    <PackageVersion Include="Meziantou.Analyzer" Version="2.0.116" />
+    <PackageVersion Include="Meziantou.Analyzer" Version="2.0.132" />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="7.0.0" />
     <PackageVersion Include="Microsoft.Extensions.TimeProvider.Testing" Version="8.0.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
     <PackageVersion Include="MongoDB.Bson.signed" Version="2.19.0" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
-    <PackageVersion Include="NiL.JS" Version="2.5.1674" />
+    <PackageVersion Include="NiL.JS" Version="2.5.1677" />
     <PackageVersion Include="NodaTime" Version="3.1.9" />
-    <PackageVersion Include="NUnit" Version="4.0.0" />
+    <PackageVersion Include="NUnit" Version="4.0.1" />
     <PackageVersion Include="NUnit3TestAdapter" Version="4.5.0" />
     <PackageVersion Include="SharpZipLib" Version="1.4.0" />
     <PackageVersion Include="Spectre.Console.Cli" Version="0.45.0" />
     <PackageVersion Include="System.Text.Json" Version="6.0.8" />
-    <PackageVersion Include="Test262Harness" Version="0.0.22" />
-    <PackageVersion Include="xunit" Version="2.6.2" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="2.5.4" PrivateAssets="all" />
+    <PackageVersion Include="Test262Harness" Version="0.0.23" />
+    <PackageVersion Include="xunit" Version="2.6.4" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="2.5.6" PrivateAssets="all" />
     <PackageVersion Include="YantraJS.Core" Version="1.2.206" />
   </ItemGroup>
   <ItemGroup>
     <GlobalPackageReference Include="GitHubActionsTestLogger" Version="2.3.3" />
     <GlobalPackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
-    <GlobalPackageReference Include="PolySharp" Version="1.14.0" />
+    <GlobalPackageReference Include="PolySharp" Version="1.14.1" />
   </ItemGroup>
 </Project>

Jint.Tests.Test262/.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "test262harness.console": {
-      "version": "0.0.22",
+      "version": "0.0.23",
       "commands": [
         "test262"
       ]

Jint.Tests/Runtime/EngineLimitTests.cs

@@ -9,9 +9,9 @@ public class EngineLimitTests
 {
 
 #if RELEASE
-    const int FunctionNestingCount = 1010;
+    const int FunctionNestingCount = 1000;
 #else
-    const int FunctionNestingCount = 510;
+    const int FunctionNestingCount = 495;
 #endif
 
     [Fact]

Jint/Engine.cs

@@ -5,6 +5,7 @@
 using Jint.Native;
 using Jint.Native.Argument;
 using Jint.Native.Function;
+using Jint.Native.Generator;
 using Jint.Native.Object;
 using Jint.Native.Promise;
 using Jint.Native.Symbol;
@@ -553,7 +554,7 @@ internal JsValue GetValue(Reference reference, bool returnReferenceToPool)
                 ExceptionHelper.ThrowReferenceError(Realm, reference);
             }
 
-            if ((baseValue._type & InternalTypes.ObjectEnvironmentRecord) == InternalTypes.None
+            if ((baseValue._type & InternalTypes.ObjectEnvironmentRecord) == InternalTypes.Empty
                 && _referenceResolver.TryPropertyReference(this, reference, ref baseValue))
             {
                 return baseValue;
@@ -584,7 +585,7 @@ internal JsValue GetValue(Reference reference, bool returnReferenceToPool)
                     // check if we are accessing a string, boxing operation can be costly to do index access
                     // we have good chance to have fast path with integer or string indexer
                     ObjectInstance? o = null;
-                    if ((property._type & (InternalTypes.String | InternalTypes.Integer)) != InternalTypes.None
+                    if ((property._type & (InternalTypes.String | InternalTypes.Integer)) != InternalTypes.Empty
                         && baseValue is JsString s
                         && TryHandleStringValue(property, s, ref o, out var jsValue))
                     {
@@ -1370,6 +1371,12 @@ internal void UpdatePrivateEnvironment(PrivateEnvironmentRecord? newEnv)
             _executionContexts.ReplaceTopPrivateEnvironment(newEnv);
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal ref readonly ExecutionContext UpdateGenerator(GeneratorInstance generator)
+        {
+            return ref _executionContexts.ReplaceTopGenerator(generator);
+        }
+
         /// <summary>
         /// Invokes the named callable and returns the resulting object.
         /// </summary>
@@ -1547,6 +1554,11 @@ internal void RegisterTypeReference(TypeReference reference)
             _typeReferences[reference.ReferenceType] = reference;
         }
 
+        internal ref readonly ExecutionContext GetExecutionContext(int fromTop)
+        {
+            return ref _executionContexts.Peek(fromTop);
+        }
+
         public void Dispose()
         {
             if (_objectWrapperCache is null)

Jint/JsValueExtensions.cs

@@ -19,7 +19,7 @@ public static class JsValueExtensions
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static bool IsPrimitive(this JsValue value)
         {
-            return (value._type & (InternalTypes.Primitive | InternalTypes.Undefined | InternalTypes.Null)) != InternalTypes.None;
+            return (value._type & (InternalTypes.Primitive | InternalTypes.Undefined | InternalTypes.Null)) != InternalTypes.Empty;
         }
 
         [Pure]
@@ -76,28 +76,28 @@ public static bool IsRegExp(this JsValue value)
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static bool IsObject(this JsValue value)
         {
-            return (value._type & InternalTypes.Object) != InternalTypes.None;
+            return (value._type & InternalTypes.Object) != InternalTypes.Empty;
         }
 
         [Pure]
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static bool IsString(this JsValue value)
         {
-            return (value._type & InternalTypes.String) != InternalTypes.None;
+            return (value._type & InternalTypes.String) != InternalTypes.Empty;
         }
 
         [Pure]
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static bool IsNumber(this JsValue value)
         {
-            return (value._type & (InternalTypes.Number | InternalTypes.Integer)) != InternalTypes.None;
+            return (value._type & (InternalTypes.Number | InternalTypes.Integer)) != InternalTypes.Empty;
         }
 
         [Pure]
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static bool IsBigInt(this JsValue value)
         {
-            return (value._type & InternalTypes.BigInt) != InternalTypes.None;
+            return (value._type & InternalTypes.BigInt) != InternalTypes.Empty;
         }
 
         [Pure]

Jint/Native/Array/ArrayInstance.cs

@@ -314,9 +314,9 @@ protected sealed override bool TryGetProperty(JsValue property, [NotNullWhen(tru
             return base.TryGetProperty(property, out descriptor);
         }
 
-        public sealed override List<JsValue> GetOwnPropertyKeys(Types types = Types.None | Types.String | Types.Symbol)
+        public sealed override List<JsValue> GetOwnPropertyKeys(Types types = Types.Empty | Types.String | Types.Symbol)
         {
-            if ((types & Types.String) == Types.None)
+            if ((types & Types.String) == Types.Empty)
             {
                 return base.GetOwnPropertyKeys(types);
             }

Jint/Native/Array/ArrayOperations.cs

@@ -56,7 +56,7 @@ public static ArrayOperations For(Realm realm, JsValue thisObj)
             for (uint i = 0; i < (uint) jsValues.Length; i++)
             {
                 var jsValue = skipHoles && !HasProperty(i) ? JsValue.Undefined : Get(i);
-                if ((jsValue.Type & elementTypes) == Types.None)
+                if ((jsValue.Type & elementTypes) == Types.Empty)
                 {
                     ExceptionHelper.ThrowTypeErrorNoEngine("invalid type");
                 }
@@ -251,7 +251,7 @@ public override JsValue[] GetAll(Types elementTypes = Types.Undefined | Types.Nu
                         value = _target.Prototype?.Get(i) ?? JsValue.Undefined;
                     }
 
-                    if ((value.Type & elementTypes) == Types.None)
+                    if ((value.Type & elementTypes) == Types.Empty)
                     {
                         ExceptionHelper.ThrowTypeErrorNoEngine("invalid type");
                     }

Jint/Native/Date/DatePrototype.cs

@@ -118,7 +118,7 @@ private JsValue ToPrimitive(JsValue thisObject, JsValue[] arguments)
             }
 
             var hintString = hint.ToString();
-            var tryFirst = Types.None;
+            var tryFirst = Types.Empty;
             if (string.Equals(hintString, "default", StringComparison.Ordinal) || string.Equals(hintString, "string", StringComparison.Ordinal))
             {
                 tryFirst = Types.String;

Jint/Native/Function/ClassDefinition.cs

@@ -89,7 +89,7 @@ public JsValue BuildConstructor(EvaluationContext context, EnvironmentRecord env
             }
             else
             {
-                var temp = superclass.Get("prototype");
+                var temp = superclass.Get(CommonProperties.Prototype);
                 if (temp is ObjectInstance protoParentObject)
                 {
                     protoParent = protoParentObject;
@@ -342,25 +342,25 @@ public ClassStaticBlockFunction(StaticBlock staticBlock) : base(Nodes.StaticBloc
     /// <summary>
     /// https://tc39.es/ecma262/#sec-runtime-semantics-methoddefinitionevaluation
     /// </summary>
-    private static PrivateElement? MethodDefinitionEvaluation(
+    internal static PrivateElement? MethodDefinitionEvaluation<T>(
         Engine engine,
         ObjectInstance obj,
-        MethodDefinition method,
-        bool enumerable)
+        T method,
+        bool enumerable) where T : IProperty
     {
-        if (method.Kind != PropertyKind.Get && method.Kind != PropertyKind.Set)
-        {
-            var methodDef = method.DefineMethod(obj);
-            methodDef.Closure.SetFunctionName(methodDef.Key);
-            return DefineMethodProperty(obj, methodDef.Key, methodDef.Closure, enumerable);
-        }
-
         var function = method.Value as IFunction;
         if (function is null)
         {
             ExceptionHelper.ThrowSyntaxError(obj.Engine.Realm);
         }
 
+        if (method.Kind != PropertyKind.Get && method.Kind != PropertyKind.Set && !function.Generator)
+        {
+            var methodDef = method.DefineMethod(obj);
+            methodDef.Closure.SetFunctionName(methodDef.Key);
+            return DefineMethodProperty(obj, methodDef.Key, methodDef.Closure, enumerable);
+        }
+
         var getter = method.Kind == PropertyKind.Get;
 
         var definition = new JintFunctionDefinition(function);
@@ -371,27 +371,39 @@ public ClassStaticBlockFunction(StaticBlock staticBlock) : base(Nodes.StaticBloc
         var env = engine.ExecutionContext.LexicalEnvironment;
         var privateEnv = engine.ExecutionContext.PrivateEnvironment;
 
-        var closure = intrinsics.Function.OrdinaryFunctionCreate(intrinsics.Function.PrototypeObject, definition, definition.ThisMode, env, privateEnv);
-        closure.MakeMethod(obj);
-        closure.SetFunctionName(propKey, getter ? "get" : "set");
-
-        if (method.Key is PrivateIdentifier privateIdentifier)
+        if (function.Generator)
         {
-            return new PrivateElement
-            {
-                Key = privateEnv!.Names[privateIdentifier],
-                Kind = PrivateElementKind.Accessor,
-                Get = getter ? closure : null,
-                Set = !getter ? closure : null
-            };
+            var closure = intrinsics.Function.OrdinaryFunctionCreate(intrinsics.GeneratorFunction.PrototypeObject, definition, definition.ThisMode, env, privateEnv);
+            closure.MakeMethod(obj);
+            closure.SetFunctionName(propKey);
+            var prototype = ObjectInstance.OrdinaryObjectCreate(engine, intrinsics.GeneratorFunction.PrototypeObject.PrototypeObject);
+            closure.DefinePropertyOrThrow(CommonProperties.Prototype, new PropertyDescriptor(prototype, PropertyFlag.Writable));
+            return DefineMethodProperty(obj, propKey, closure, enumerable);
         }
+        else
+        {
+            var closure = intrinsics.Function.OrdinaryFunctionCreate(intrinsics.Function.PrototypeObject, definition, definition.ThisMode, env, privateEnv);
+            closure.MakeMethod(obj);
+            closure.SetFunctionName(propKey, getter ? "get" : "set");
 
-        var propDesc = new GetSetPropertyDescriptor(
-            getter ? closure : null,
-            !getter ? closure : null,
-            PropertyFlag.Configurable);
+            if (method.Key is PrivateIdentifier privateIdentifier)
+            {
+                return new PrivateElement
+                {
+                    Key = privateEnv!.Names[privateIdentifier],
+                    Kind = PrivateElementKind.Accessor,
+                    Get = getter ? closure : null,
+                    Set = !getter ? closure : null
+                };
+            }
 
-        obj.DefinePropertyOrThrow(propKey, propDesc);
+            var propDesc = new GetSetPropertyDescriptor(
+                getter ? closure : null,
+                !getter ? closure : null,
+                PropertyFlag.Configurable);
+
+            obj.DefinePropertyOrThrow(propKey, propDesc);
+        }
 
         return null;
     }
@@ -406,7 +418,7 @@ public ClassStaticBlockFunction(StaticBlock staticBlock) : base(Nodes.StaticBloc
             return new PrivateElement { Key = (PrivateName) key, Kind = PrivateElementKind.Method, Value = closure };
         }
 
-        var desc = new PropertyDescriptor(closure, enumerable ? PropertyFlag.Enumerable : PropertyFlag.NonEnumerable);
+        var desc = new PropertyDescriptor(closure, enumerable ? PropertyFlag.ConfigurableEnumerableWritable : PropertyFlag.NonEnumerable);
         homeObject.DefinePropertyOrThrow(key, desc);
         return null;
     }

Jint/Native/Function/FunctionKind.cs

@@ -1,10 +1,9 @@
-namespace Jint.Native.Function
+namespace Jint.Native.Function;
+
+internal enum FunctionKind
 {
-    internal enum FunctionKind
-    {
-        Normal,
-        Async,
-        Generator,
-        AsyncGenerator
-    }
+    Normal,
+    Async,
+    Generator,
+    AsyncGenerator
 }

Jint/Native/Generator/GeneratorFunctionConstructor.cs

@@ -0,0 +1,46 @@
+using Jint.Native.Function;
+using Jint.Native.Iterator;
+using Jint.Native.Object;
+using Jint.Runtime;
+using Jint.Runtime.Descriptors;
+
+namespace Jint.Native.Generator;
+
+/// <summary>
+/// https://tc39.es/ecma262/#sec-generatorfunction-constructor
+/// </summary>
+internal sealed class GeneratorFunctionConstructor : Constructor
+{
+    private static readonly JsString _functionName = new("GeneratorFunction");
+
+    internal GeneratorFunctionConstructor(
+        Engine engine,
+        Realm realm,
+        FunctionPrototype prototype,
+        IteratorPrototype iteratorPrototype)
+        : base(engine, realm, _functionName)
+    {
+        PrototypeObject = new GeneratorFunctionPrototype(engine, this, prototype, iteratorPrototype);
+        _prototype = PrototypeObject;
+        _prototypeDescriptor = new PropertyDescriptor(PrototypeObject, PropertyFlag.AllForbidden);
+        _length = new PropertyDescriptor(JsNumber.PositiveOne, PropertyFlag.Configurable);
+    }
+
+    public GeneratorFunctionPrototype PrototypeObject { get; }
+
+    protected internal override JsValue Call(JsValue thisObject, JsValue[] arguments)
+    {
+        return Construct(arguments, thisObject);
+    }
+
+    public override ObjectInstance Construct(JsValue[] arguments, JsValue newTarget)
+    {
+        var function = _realm.Intrinsics.Function.CreateDynamicFunction(
+            this,
+            newTarget,
+            FunctionKind.Generator,
+            arguments);
+
+        return function;
+    }
+}