microsoft · weswigham · Jun 5, 2019 · May 23, 2019 · May 31, 2019
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -5231,7 +5231,7 @@ namespace ts {
                     }
                 }
                 // Use contextual parameter type if one is available
-                const type = declaration.symbol.escapedName === InternalSymbolName.This ? getContextualThisParameterType(func) : getContextuallyTypedParameterType(declaration);
+                const type = declaration.symbol.escapedName === InternalSymbolName.This ? getContextualThisParameterType(func) : getContextuallyTypedParameterType(declaration, /*forCache*/ true);
                 if (type) {
                     return addOptionality(type, isOptional);
                 }
@@ -11515,6 +11515,7 @@ namespace ts {
                 case SyntaxKind.FunctionExpression:
                 case SyntaxKind.ArrowFunction:
                 case SyntaxKind.MethodDeclaration:
+                case SyntaxKind.FunctionDeclaration: // Function declarations can have context when annotated with a jsdoc @type
                     return isContextSensitiveFunctionLikeDeclaration(<FunctionExpression | ArrowFunction | MethodDeclaration>node);
                 case SyntaxKind.ObjectLiteralExpression:
                     return some((<ObjectLiteralExpression>node).properties, isContextSensitive);
@@ -11548,6 +11549,9 @@ namespace ts {
         }
 
         function isContextSensitiveFunctionLikeDeclaration(node: FunctionLikeDeclaration): boolean {
+            if (isFunctionDeclaration(node) && (!isInJSFile(node) || !getTypeForDeclarationFromJSDocComment(node))) {
+                return false;
+            }
             // Functions with type parameters are not context sensitive.
             if (node.typeParameters) {
                 return false;
@@ -18241,7 +18245,7 @@ namespace ts {
         }
 
         // Return contextual type of parameter or undefined if no contextual type is available
-        function getContextuallyTypedParameterType(parameter: ParameterDeclaration): Type | undefined {
+        function getContextuallyTypedParameterType(parameter: ParameterDeclaration, forCache: boolean): Type | undefined {
             const func = parameter.parent;
             if (!isContextSensitiveFunctionOrObjectLiteralMethod(func)) {
                 return undefined;
@@ -18262,8 +18266,21 @@ namespace ts {
                 links.resolvedSignature = cached;
                 return type;
             }
-            const contextualSignature = getContextualSignature(func);
+            let contextualSignature = getContextualSignature(func);
             if (contextualSignature) {
+                if (forCache) {
+                    // Calling the below guarantees the types are primed and assigned in the same way
+                    // as when the parameter is reached via `checkFunctionExpressionOrObjectLiteralMethod`.
+                    // This should prevent any uninstantiated inference variables in the contextual signature
+                    // from leaking, and should lock in cached parameter types via `assignContextualParameterTypes`
+                    // which we will then immediately use the results of below.
+                    contextuallyCheckFunctionExpressionOrObjectLiteralMethod(func);
+                    const type = getTypeOfSymbol(getMergedSymbol(func.symbol));
+                    if (isTypeAny(type)) {
+                        return type;
+                    }
+                    contextualSignature = getSignaturesOfType(type, SignatureKind.Call)[0];
+                }
                 const index = func.parameters.indexOf(parameter) - (getThisParameter(func) ? 1 : 0);
                 return parameter.dotDotDotToken && lastOrUndefined(func.parameters) === parameter ?
                     getRestTypeAtPosition(contextualSignature, index) :
@@ -18278,7 +18295,7 @@ namespace ts {
             }
             switch (declaration.kind) {
                 case SyntaxKind.Parameter:
-                    return getContextuallyTypedParameterType(declaration);
+                    return getContextuallyTypedParameterType(declaration, /*forCache*/ false);
                 case SyntaxKind.BindingElement:
                     return getContextualTypeForBindingElement(declaration);
                 // By default, do nothing and return undefined - only parameters and binding elements have context implied by a parent
@@ -23053,12 +23070,18 @@ namespace ts {
                 checkGrammarForGenerator(node);
             }
 
-            const links = getNodeLinks(node);
             const type = getTypeOfSymbol(getMergedSymbol(node.symbol));
             if (isTypeAny(type)) {
                 return type;
             }
 
+            contextuallyCheckFunctionExpressionOrObjectLiteralMethod(node, checkMode);
+
+            return type;
+        }
+
+        function contextuallyCheckFunctionExpressionOrObjectLiteralMethod(node: FunctionExpression | ArrowFunction | MethodDeclaration, checkMode?: CheckMode) {
+            const links = getNodeLinks(node);
             // Check if function expression is contextually typed and assign parameter types if so.
             if (!(links.flags & NodeCheckFlags.ContextChecked)) {
                 const contextualSignature = getContextualSignature(node);
@@ -23068,6 +23091,10 @@ namespace ts {
                 if (!(links.flags & NodeCheckFlags.ContextChecked)) {
                     links.flags |= NodeCheckFlags.ContextChecked;
                     if (contextualSignature) {
+                        const type = getTypeOfSymbol(getMergedSymbol(node.symbol));
+                        if (isTypeAny(type)) {
+                            return;
+                        }
                         const signature = getSignaturesOfType(type, SignatureKind.Call)[0];
                         if (isContextSensitive(node)) {
                             const inferenceContext = getInferenceContext(node);
@@ -23088,8 +23115,6 @@ namespace ts {
                     checkSignatureDeclaration(node);
                 }
             }
-
-            return type;
         }
 
         function getReturnOrPromisedType(node: FunctionLikeDeclaration | MethodSignature, functionFlags: FunctionFlags) {

diff --git a/tests/baselines/reference/fallbackToBindingPatternForTypeInference.symbols b/tests/baselines/reference/fallbackToBindingPatternForTypeInference.symbols
@@ -18,6 +18,7 @@ trans(([b,c]) => 'foo');
 
 trans(({d: [e,f]}) => 'foo');
 >trans : Symbol(trans, Decl(fallbackToBindingPatternForTypeInference.ts, 0, 0))
+>d : Symbol(d)
 >e : Symbol(e, Decl(fallbackToBindingPatternForTypeInference.ts, 3, 12))
 >f : Symbol(f, Decl(fallbackToBindingPatternForTypeInference.ts, 3, 14))
 

diff --git a/tests/baselines/reference/inferenceDoesntCompareAgainstUninstantiatedTypeParameter.js b/tests/baselines/reference/inferenceDoesntCompareAgainstUninstantiatedTypeParameter.js
@@ -0,0 +1,67 @@
+//// [inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts]
+class ClassA<TEntityClass>  {
+    constructor(private entity?: TEntityClass, public settings?: SettingsInterface<TEntityClass>) {
+
+    }
+}
+export interface ValueInterface<TValueClass> {
+    func?: (row: TValueClass) => any;
+    value?: string;
+}
+export interface SettingsInterface<TClass> {
+    values?: (row: TClass) => ValueInterface<TClass>[],
+}
+class ConcreteClass {
+    theName = 'myClass';
+}
+
+var thisGetsTheFalseError = new ClassA(new ConcreteClass(), {
+    values: o => [
+        {
+            value: o.theName,
+            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'
+        }
+    ]
+});
+
+var thisIsOk = new ClassA<ConcreteClass>(new ConcreteClass(), {
+    values: o => [
+        {
+            value: o.theName,
+            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'
+        }
+    ]
+});
+
+//// [inferenceDoesntCompareAgainstUninstantiatedTypeParameter.js]
+"use strict";
+exports.__esModule = true;
+var ClassA = /** @class */ (function () {
+    function ClassA(entity, settings) {
+        this.entity = entity;
+        this.settings = settings;
+    }
+    return ClassA;
+}());
+var ConcreteClass = /** @class */ (function () {
+    function ConcreteClass() {
+        this.theName = 'myClass';
+    }
+    return ConcreteClass;
+}());
+var thisGetsTheFalseError = new ClassA(new ConcreteClass(), {
+    values: function (o) { return [
+        {
+            value: o.theName,
+            func: function (x) { return 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'; }
+        }
+    ]; }
+});
+var thisIsOk = new ClassA(new ConcreteClass(), {
+    values: function (o) { return [
+        {
+            value: o.theName,
+            func: function (x) { return 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'; }
+        }
+    ]; }
+});
diff --git a/tests/baselines/reference/inferenceDoesntCompareAgainstUninstantiatedTypeParameter.symbols b/tests/baselines/reference/inferenceDoesntCompareAgainstUninstantiatedTypeParameter.symbols
@@ -0,0 +1,88 @@
+=== tests/cases/compiler/inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts ===
+class ClassA<TEntityClass>  {
+>ClassA : Symbol(ClassA, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 0, 0))
+>TEntityClass : Symbol(TEntityClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 0, 13))
+
+    constructor(private entity?: TEntityClass, public settings?: SettingsInterface<TEntityClass>) {
+>entity : Symbol(ClassA.entity, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 1, 16))
+>TEntityClass : Symbol(TEntityClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 0, 13))
+>settings : Symbol(ClassA.settings, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 1, 46))
+>SettingsInterface : Symbol(SettingsInterface, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 8, 1))
+>TEntityClass : Symbol(TEntityClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 0, 13))
+
+    }
+}
+export interface ValueInterface<TValueClass> {
+>ValueInterface : Symbol(ValueInterface, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 4, 1))
+>TValueClass : Symbol(TValueClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 5, 32))
+
+    func?: (row: TValueClass) => any;
+>func : Symbol(ValueInterface.func, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 5, 46))
+>row : Symbol(row, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 6, 12))
+>TValueClass : Symbol(TValueClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 5, 32))
+
+    value?: string;
+>value : Symbol(ValueInterface.value, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 6, 37))
+}
+export interface SettingsInterface<TClass> {
+>SettingsInterface : Symbol(SettingsInterface, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 8, 1))
+>TClass : Symbol(TClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 9, 35))
+
+    values?: (row: TClass) => ValueInterface<TClass>[],
+>values : Symbol(SettingsInterface.values, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 9, 44))
+>row : Symbol(row, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 10, 14))
+>TClass : Symbol(TClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 9, 35))
+>ValueInterface : Symbol(ValueInterface, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 4, 1))
+>TClass : Symbol(TClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 9, 35))
+}
+class ConcreteClass {
+>ConcreteClass : Symbol(ConcreteClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 11, 1))
+
+    theName = 'myClass';
+>theName : Symbol(ConcreteClass.theName, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 12, 21))
+}
+
+var thisGetsTheFalseError = new ClassA(new ConcreteClass(), {
+>thisGetsTheFalseError : Symbol(thisGetsTheFalseError, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 16, 3))
+>ClassA : Symbol(ClassA, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 0, 0))
+>ConcreteClass : Symbol(ConcreteClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 11, 1))
+
+    values: o => [
+>values : Symbol(values, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 16, 61))
+>o : Symbol(o, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 17, 11))
+        {
+            value: o.theName,
+>value : Symbol(value, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 18, 9))
+>o.theName : Symbol(ConcreteClass.theName, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 12, 21))
+>o : Symbol(o, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 17, 11))
+>theName : Symbol(ConcreteClass.theName, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 12, 21))
+
+            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'
+>func : Symbol(func, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 19, 29))
+>x : Symbol(x, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 20, 17))
+        }
+    ]
+});
+
+var thisIsOk = new ClassA<ConcreteClass>(new ConcreteClass(), {
+>thisIsOk : Symbol(thisIsOk, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 25, 3))
+>ClassA : Symbol(ClassA, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 0, 0))
+>ConcreteClass : Symbol(ConcreteClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 11, 1))
+>ConcreteClass : Symbol(ConcreteClass, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 11, 1))
+
+    values: o => [
+>values : Symbol(values, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 25, 63))
+>o : Symbol(o, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 26, 11))
+        {
+            value: o.theName,
+>value : Symbol(value, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 27, 9))
+>o.theName : Symbol(ConcreteClass.theName, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 12, 21))
+>o : Symbol(o, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 26, 11))
+>theName : Symbol(ConcreteClass.theName, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 12, 21))
+
+            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'
+>func : Symbol(func, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 28, 29))
+>x : Symbol(x, Decl(inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts, 29, 17))
+        }
+    ]
+});
diff --git a/tests/baselines/reference/inferenceDoesntCompareAgainstUninstantiatedTypeParameter.types b/tests/baselines/reference/inferenceDoesntCompareAgainstUninstantiatedTypeParameter.types
@@ -0,0 +1,92 @@
+=== tests/cases/compiler/inferenceDoesntCompareAgainstUninstantiatedTypeParameter.ts ===
+class ClassA<TEntityClass>  {
+>ClassA : ClassA<TEntityClass>
+
+    constructor(private entity?: TEntityClass, public settings?: SettingsInterface<TEntityClass>) {
+>entity : TEntityClass
+>settings : SettingsInterface<TEntityClass>
+
+    }
+}
+export interface ValueInterface<TValueClass> {
+    func?: (row: TValueClass) => any;
+>func : (row: TValueClass) => any
+>row : TValueClass
+
+    value?: string;
+>value : string
+}
+export interface SettingsInterface<TClass> {
+    values?: (row: TClass) => ValueInterface<TClass>[],
+>values : (row: TClass) => ValueInterface<TClass>[]
+>row : TClass
+}
+class ConcreteClass {
+>ConcreteClass : ConcreteClass
+
+    theName = 'myClass';
+>theName : string
+>'myClass' : "myClass"
+}
+
+var thisGetsTheFalseError = new ClassA(new ConcreteClass(), {
+>thisGetsTheFalseError : ClassA<ConcreteClass>
+>new ClassA(new ConcreteClass(), {    values: o => [        {            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        }    ]}) : ClassA<ConcreteClass>
+>ClassA : typeof ClassA
+>new ConcreteClass() : ConcreteClass
+>ConcreteClass : typeof ConcreteClass
+>{    values: o => [        {            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        }    ]} : { values: (o: ConcreteClass) => { value: string; func: (x: ConcreteClass) => string; }[]; }
+
+    values: o => [
+>values : (o: ConcreteClass) => { value: string; func: (x: ConcreteClass) => string; }[]
+>o => [        {            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        }    ] : (o: ConcreteClass) => { value: string; func: (x: ConcreteClass) => string; }[]
+>o : ConcreteClass
+>[        {            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        }    ] : { value: string; func: (x: ConcreteClass) => string; }[]
+        {
+>{            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        } : { value: string; func: (x: ConcreteClass) => string; }
+
+            value: o.theName,
+>value : string
+>o.theName : string
+>o : ConcreteClass
+>theName : string
+
+            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'
+>func : (x: ConcreteClass) => string
+>x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj' : (x: ConcreteClass) => string
+>x : ConcreteClass
+>'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj' : "asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj"
+        }
+    ]
+});
+
+var thisIsOk = new ClassA<ConcreteClass>(new ConcreteClass(), {
+>thisIsOk : ClassA<ConcreteClass>
+>new ClassA<ConcreteClass>(new ConcreteClass(), {    values: o => [        {            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        }    ]}) : ClassA<ConcreteClass>
+>ClassA : typeof ClassA
+>new ConcreteClass() : ConcreteClass
+>ConcreteClass : typeof ConcreteClass
+>{    values: o => [        {            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        }    ]} : { values: (o: ConcreteClass) => { value: string; func: (x: ConcreteClass) => string; }[]; }
+
+    values: o => [
+>values : (o: ConcreteClass) => { value: string; func: (x: ConcreteClass) => string; }[]
+>o => [        {            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        }    ] : (o: ConcreteClass) => { value: string; func: (x: ConcreteClass) => string; }[]
+>o : ConcreteClass
+>[        {            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        }    ] : { value: string; func: (x: ConcreteClass) => string; }[]
+        {
+>{            value: o.theName,            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'        } : { value: string; func: (x: ConcreteClass) => string; }
+
+            value: o.theName,
+>value : string
+>o.theName : string
+>o : ConcreteClass
+>theName : string
+
+            func: x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj'
+>func : (x: ConcreteClass) => string
+>x => 'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj' : (x: ConcreteClass) => string
+>x : ConcreteClass
+>'asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj' : "asdfkjhgfdfghjkjhgfdfghjklkjhgfdfghjklkjhgfghj"
+        }
+    ]
+});