Support indexing with known symbols

microsoft · Feb 7, 2015 · d07ed67 · yuit · Feb 10, 2015 · JsonFreeman
1 parent df826de
commit d07ed67
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Showing 26 changed files with 495 additions and 14 deletions.
diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
@@ -97,7 +97,7 @@ module ts {
                 if (node.name.kind === SyntaxKind.ComputedPropertyName) {
                     var nameExpression = (<ComputedPropertyName>node.name).expression;
                     Debug.assert(isWellKnownSymbolSyntactically(nameExpression));
-                    return "__@" + (<PropertyAccessExpression>nameExpression).name.text;
+                    return getPropertyNameForKnownSymbolName((<PropertyAccessExpression>nameExpression).name.text);
                 }
                 return (<Identifier | LiteralExpression>node.name).text;
             }

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -5787,8 +5787,8 @@ module ts {
 
             // See if we can index as a property.
             if (node.argumentExpression) {
-                if (node.argumentExpression.kind === SyntaxKind.StringLiteral || node.argumentExpression.kind === SyntaxKind.NumericLiteral) {
-                    var name = (<LiteralExpression>node.argumentExpression).text;
+                var name = getPropertyNameForIndexedAccess(node.argumentExpression);
+                if (name !== undefined) {
                     var prop = getPropertyOfType(objectType, name);
                     if (prop) {
                         getNodeLinks(node).resolvedSymbol = prop;
@@ -5832,6 +5832,36 @@ module ts {
             return unknownType;
         }
 
+        /**
+         * If indexArgumentExpression is a string literal or number literal, returns its text.
+         * If indexArgumentExpression is a well known symbol, returns the property name corresponding
+         *    to this symbol.
+         * Otherwise, returns undefined.
+         */
+        function getPropertyNameForIndexedAccess(indexArgumentExpression: Expression) {
+            if (indexArgumentExpression.kind === SyntaxKind.StringLiteral || indexArgumentExpression.kind === SyntaxKind.NumericLiteral) {
+                return (<LiteralExpression>indexArgumentExpression).text;
+            }
+            if (isWellKnownSymbolSyntactically(indexArgumentExpression)) {
+                var leftHandSide = (<PropertyAccessExpression>indexArgumentExpression).expression;
+                Debug.assert((<Identifier>leftHandSide).text === "Symbol");
+                // The name is Symbol.<someName>, so make sure Symbol actually resolves to the
+                // global Symbol object
+                var leftHandSideSymbol = resolveName(indexArgumentExpression, (<Identifier>leftHandSide).text,
+                    SymbolFlags.Value, /*nameNotFoundMessage*/ undefined, /*nameArg*/ undefined);
+                if (leftHandSideSymbol === globalESSymbolConstructorSymbol) {
+                    // Make sure the property type is the primitive symbol type
+                    var rightHandSideName = (<Identifier>(<PropertyAccessExpression>indexArgumentExpression).name).text;
+                    var esSymbolConstructorPropertyType = getTypeOfPropertyOfType(globalESSymbolConstructorType, rightHandSideName);
+                    if (esSymbolConstructorPropertyType && esSymbolConstructorPropertyType.flags & TypeFlags.ESSymbol) {
+                        return getPropertyNameForKnownSymbolName(rightHandSideName);
+                    }
+                }
+            }
+
+            return undefined;
+        }
+
         function resolveUntypedCall(node: CallLikeExpression): Signature {
             if (node.kind === SyntaxKind.TaggedTemplateExpression) {
                 checkExpression((<TaggedTemplateExpression>node).template);
@@ -10334,7 +10364,7 @@ module ts {
                 globalTemplateStringsArrayType = getGlobalType("TemplateStringsArray");
                 globalESSymbolType = getGlobalType("Symbol");
                 globalESSymbolConstructorSymbol = getGlobalValueSymbol("Symbol");
-                globalESSymbolConstructorType = getTypeOfGlobalSymbol(globalESSymbolConstructorSymbol, /*arity*/ 0);
+                globalESSymbolConstructorType = getTypeOfSymbol(globalESSymbolConstructorSymbol);
             }
             else {
                 globalTemplateStringsArrayType = unknownType;

diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
@@ -852,6 +852,10 @@ module ts {
         return node.kind === SyntaxKind.PropertyAccessExpression && isESSymbolIdentifier((<PropertyAccessExpression>node).expression);
     }
 
+    export function getPropertyNameForKnownSymbolName(symbolName: string): string {
+        return "__@" + symbolName;
+    }
+
     /**
      * Includes the word "Symbol" with unicode escapes
      */

diff --git a/tests/baselines/reference/symbolProperty17.types b/tests/baselines/reference/symbolProperty17.types
@@ -0,0 +1,27 @@
+=== tests/cases/conformance/es6/Symbols/symbolProperty17.ts ===
+interface I {
+>I : I
+
+    [Symbol.iterator]: number;
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
+    [s: symbol]: string;
+>s : symbol
+
+    "__@iterator": string;
+}
+
+var i: I;
+>i : I
+>I : I
+
+var it = i[Symbol.iterator];
+>it : number
+>i[Symbol.iterator] : number
+>i : I
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
diff --git a/tests/baselines/reference/symbolProperty18.types b/tests/baselines/reference/symbolProperty18.types
@@ -0,0 +1,47 @@
+=== tests/cases/conformance/es6/Symbols/symbolProperty18.ts ===
+var i = {
+>i : { [Symbol.iterator]: number; [Symbol.toStringTag](): string; [Symbol.toPrimitive]: boolean; }
+>{    [Symbol.iterator]: 0,    [Symbol.toStringTag]() { return "" },    set [Symbol.toPrimitive](p: boolean) { }} : { [Symbol.iterator]: number; [Symbol.toStringTag](): string; [Symbol.toPrimitive]: boolean; }
+
+    [Symbol.iterator]: 0,
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
+    [Symbol.toStringTag]() { return "" },
+>Symbol.toStringTag : symbol
+>Symbol : SymbolConstructor
+>toStringTag : symbol
+
+    set [Symbol.toPrimitive](p: boolean) { }
+>Symbol.toPrimitive : symbol
+>Symbol : SymbolConstructor
+>toPrimitive : symbol
+>p : boolean
+}
+
+var it = i[Symbol.iterator];
+>it : number
+>i[Symbol.iterator] : number
+>i : { [Symbol.iterator]: number; [Symbol.toStringTag](): string; [Symbol.toPrimitive]: boolean; }
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
+var str = i[Symbol.toStringTag]();
+>str : string
+>i[Symbol.toStringTag]() : string
+>i[Symbol.toStringTag] : () => string
+>i : { [Symbol.iterator]: number; [Symbol.toStringTag](): string; [Symbol.toPrimitive]: boolean; }
+>Symbol.toStringTag : symbol
+>Symbol : SymbolConstructor
+>toStringTag : symbol
+
+i[Symbol.toPrimitive] = false;
+>i[Symbol.toPrimitive] = false : boolean
+>i[Symbol.toPrimitive] : boolean
+>i : { [Symbol.iterator]: number; [Symbol.toStringTag](): string; [Symbol.toPrimitive]: boolean; }
+>Symbol.toPrimitive : symbol
+>Symbol : SymbolConstructor
+>toPrimitive : symbol
+
diff --git a/tests/baselines/reference/symbolProperty19.types b/tests/baselines/reference/symbolProperty19.types
@@ -0,0 +1,38 @@
+=== tests/cases/conformance/es6/Symbols/symbolProperty19.ts ===
+var i = {
+>i : { [Symbol.iterator]: { p: any; }; [Symbol.toStringTag](): { p: any; }; }
+>{    [Symbol.iterator]: { p: null },    [Symbol.toStringTag]() { return { p: undefined }; }} : { [Symbol.iterator]: { p: null; }; [Symbol.toStringTag](): { p: any; }; }
+
+    [Symbol.iterator]: { p: null },
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+>{ p: null } : { p: null; }
+>p : null
+
+    [Symbol.toStringTag]() { return { p: undefined }; }
+>Symbol.toStringTag : symbol
+>Symbol : SymbolConstructor
+>toStringTag : symbol
+>{ p: undefined } : { p: undefined; }
+>p : undefined
+>undefined : undefined
+}
+
+var it = i[Symbol.iterator];
+>it : { p: any; }
+>i[Symbol.iterator] : { p: any; }
+>i : { [Symbol.iterator]: { p: any; }; [Symbol.toStringTag](): { p: any; }; }
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
+var str = i[Symbol.toStringTag]();
+>str : { p: any; }
+>i[Symbol.toStringTag]() : { p: any; }
+>i[Symbol.toStringTag] : () => { p: any; }
+>i : { [Symbol.iterator]: { p: any; }; [Symbol.toStringTag](): { p: any; }; }
+>Symbol.toStringTag : symbol
+>Symbol : SymbolConstructor
+>toStringTag : symbol
+
diff --git a/tests/baselines/reference/symbolProperty28.types b/tests/baselines/reference/symbolProperty28.types
@@ -0,0 +1,34 @@
+=== tests/cases/conformance/es6/Symbols/symbolProperty28.ts ===
+class C1 {
+>C1 : C1
+
+    [Symbol.toStringTag]() {
+>Symbol.toStringTag : symbol
+>Symbol : SymbolConstructor
+>toStringTag : symbol
+
+        return { x: "" };
+>{ x: "" } : { x: string; }
+>x : string
+    }
+}
+
+class C2 extends C1 { }
+>C2 : C2
+>C1 : C1
+
+var c: C2;
+>c : C2
+>C2 : C2
+
+var obj = c[Symbol.toStringTag]().x;
+>obj : string
+>c[Symbol.toStringTag]().x : string
+>c[Symbol.toStringTag]() : { x: string; }
+>c[Symbol.toStringTag] : () => { x: string; }
+>c : C2
+>Symbol.toStringTag : symbol
+>Symbol : SymbolConstructor
+>toStringTag : symbol
+>x : string
+
diff --git a/tests/baselines/reference/symbolProperty40.types b/tests/baselines/reference/symbolProperty40.types
@@ -0,0 +1,48 @@
+=== tests/cases/conformance/es6/Symbols/symbolProperty40.ts ===
+class C {
+>C : C
+
+    [Symbol.iterator](x: string): string;
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+>x : string
+
+    [Symbol.iterator](x: number): number;
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+>x : number
+
+    [Symbol.iterator](x: any) {
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+>x : any
+
+        return undefined;
+>undefined : undefined
+    }
+}
+
+var c = new C;
+>c : C
+>new C : C
+>C : typeof C
+
+c[Symbol.iterator]("");
+>c[Symbol.iterator]("") : string
+>c[Symbol.iterator] : { (x: string): string; (x: number): number; }
+>c : C
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
+c[Symbol.iterator](0);
+>c[Symbol.iterator](0) : number
+>c[Symbol.iterator] : { (x: string): string; (x: number): number; }
+>c : C
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
diff --git a/tests/baselines/reference/symbolProperty41.types b/tests/baselines/reference/symbolProperty41.types
@@ -0,0 +1,51 @@
+=== tests/cases/conformance/es6/Symbols/symbolProperty41.ts ===
+class C {
+>C : C
+
+    [Symbol.iterator](x: string): { x: string };
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+>x : string
+>x : string
+
+    [Symbol.iterator](x: "hello"): { x: string; hello: string };
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+>x : "hello"
+>x : string
+>hello : string
+
+    [Symbol.iterator](x: any) {
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+>x : any
+
+        return undefined;
+>undefined : undefined
+    }
+}
+
+var c = new C;
+>c : C
+>new C : C
+>C : typeof C
+
+c[Symbol.iterator]("");
+>c[Symbol.iterator]("") : { x: string; }
+>c[Symbol.iterator] : { (x: string): { x: string; }; (x: "hello"): { x: string; hello: string; }; }
+>c : C
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
+c[Symbol.iterator]("hello");
+>c[Symbol.iterator]("hello") : { x: string; hello: string; }
+>c[Symbol.iterator] : { (x: string): { x: string; }; (x: "hello"): { x: string; hello: string; }; }
+>c : C
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+
diff --git a/tests/baselines/reference/symbolProperty46.errors.txt b/tests/baselines/reference/symbolProperty46.errors.txt
@@ -0,0 +1,17 @@
+tests/cases/conformance/es6/Symbols/symbolProperty46.ts(10,1): error TS2322: Type 'number' is not assignable to type 'string'.
+
+
+==== tests/cases/conformance/es6/Symbols/symbolProperty46.ts (1 errors) ====
+    class C {
+        get [Symbol.hasInstance]() {
+            return "";
+        }
+        // Should take a string
+        set [Symbol.hasInstance](x) {
+        }
+    }
+
+    (new C)[Symbol.hasInstance] = 0;
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
+    (new C)[Symbol.hasInstance] = "";
diff --git a/tests/baselines/reference/symbolProperty47.errors.txt b/tests/baselines/reference/symbolProperty47.errors.txt
@@ -1,7 +1,8 @@
 tests/cases/conformance/es6/Symbols/symbolProperty47.ts(3,16): error TS2322: Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/es6/Symbols/symbolProperty47.ts(11,1): error TS2322: Type 'string' is not assignable to type 'number'.
 
 
-==== tests/cases/conformance/es6/Symbols/symbolProperty47.ts (1 errors) ====
+==== tests/cases/conformance/es6/Symbols/symbolProperty47.ts (2 errors) ====
     class C {
         get [Symbol.hasInstance]() {
             return "";
@@ -14,4 +15,6 @@ tests/cases/conformance/es6/Symbols/symbolProperty47.ts(3,16): error TS2322: Typ
     }
 
     (new C)[Symbol.hasInstance] = 0;
-    (new C)[Symbol.hasInstance] = "";
+    (new C)[Symbol.hasInstance] = "";
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
diff --git a/tests/baselines/reference/symbolProperty52.errors.txt b/tests/baselines/reference/symbolProperty52.errors.txt
@@ -1,9 +1,10 @@
 tests/cases/conformance/es6/Symbols/symbolProperty52.ts(2,13): error TS2339: Property 'nonsense' does not exist on type 'SymbolConstructor'.
 tests/cases/conformance/es6/Symbols/symbolProperty52.ts(5,1): error TS2322: Type '{}' is not assignable to type '{ [Symbol.nonsense]: number; }'.
   Property '[Symbol.nonsense]' is missing in type '{}'.
+tests/cases/conformance/es6/Symbols/symbolProperty52.ts(7,12): error TS2339: Property 'nonsense' does not exist on type 'SymbolConstructor'.
 
 
-==== tests/cases/conformance/es6/Symbols/symbolProperty52.ts (2 errors) ====
+==== tests/cases/conformance/es6/Symbols/symbolProperty52.ts (3 errors) ====
     var obj = {
         [Symbol.nonsense]: 0
                 ~~~~~~~~
@@ -13,4 +14,8 @@ tests/cases/conformance/es6/Symbols/symbolProperty52.ts(5,1): error TS2322: Type
     obj = {};
     ~~~
 !!! error TS2322: Type '{}' is not assignable to type '{ [Symbol.nonsense]: number; }'.
-!!! error TS2322:   Property '[Symbol.nonsense]' is missing in type '{}'.
+!!! error TS2322:   Property '[Symbol.nonsense]' is missing in type '{}'.
+
+    obj[Symbol.nonsense];
+               ~~~~~~~~
+!!! error TS2339: Property 'nonsense' does not exist on type 'SymbolConstructor'.