Create WeakMaps for Private Named Instance Fields

.travis.yml

@@ -15,12 +15,7 @@ matrix:
 
 branches:
   only:
-  - master
-  - release-2.7
-  - release-2.8
-  - release-2.9
-  - release-3.0
-  - release-3.1
+  - es-private-fields
 
 install:
   - npm uninstall typescript --no-save

src/compiler/binder.ts

@@ -271,6 +271,9 @@ namespace ts {
                     Debug.assert(isWellKnownSymbolSyntactically(nameExpression));
                     return getPropertyNameForKnownSymbolName(idText((<PropertyAccessExpression>nameExpression).name));
                 }
+                if (isPrivateName(node)) {
+                    return nodePosToString(node) as __String;
+                }
                 return isPropertyNameLiteral(name) ? getEscapedTextOfIdentifierOrLiteral(name) : undefined;
             }
             switch (node.kind) {
@@ -1402,7 +1405,7 @@ namespace ts {
             }
             if (node.expression.kind === SyntaxKind.PropertyAccessExpression) {
                 const propertyAccess = <PropertyAccessExpression>node.expression;
-                if (isNarrowableOperand(propertyAccess.expression) && isPushOrUnshiftIdentifier(propertyAccess.name)) {
+                if (isIdentifier(propertyAccess.name) && isNarrowableOperand(propertyAccess.expression) && isPushOrUnshiftIdentifier(propertyAccess.name)) {
                     currentFlow = createFlowArrayMutation(currentFlow, node);
                 }
             }
@@ -2358,7 +2361,7 @@ namespace ts {
                 return;
             }
             const lhs = node.left as PropertyAccessEntityNameExpression;
-            const symbol = forEachIdentifierInEntityName(lhs.expression, /*parent*/ undefined, (id, symbol) => {
+            const symbol = forEachIdentifierOrPrivateNameInEntityName(lhs.expression, /*parent*/ undefined, (id, symbol) => {
                 if (symbol) {
                     addDeclarationToSymbol(symbol, id, SymbolFlags.Module | SymbolFlags.Assignment);
                 }
@@ -2516,7 +2519,7 @@ namespace ts {
                 // make symbols or add declarations for intermediate containers
                 const flags = SymbolFlags.Module | SymbolFlags.Assignment;
                 const excludeFlags = SymbolFlags.ValueModuleExcludes & ~SymbolFlags.Assignment;
-                namespaceSymbol = forEachIdentifierInEntityName(propertyAccess.expression, namespaceSymbol, (id, symbol, parent) => {
+                namespaceSymbol = forEachIdentifierOrPrivateNameInEntityName(propertyAccess.expression, namespaceSymbol, (id, symbol, parent) => {
                     if (symbol) {
                         addDeclarationToSymbol(symbol, id, flags);
                         return symbol;
@@ -2588,15 +2591,15 @@ namespace ts {
             }
         }
 
-        function forEachIdentifierInEntityName(e: EntityNameExpression, parent: Symbol | undefined, action: (e: Identifier, symbol: Symbol | undefined, parent: Symbol | undefined) => Symbol | undefined): Symbol | undefined {
+        function forEachIdentifierOrPrivateNameInEntityName(e: EntityNameExpression, parent: Symbol | undefined, action: (e: Identifier | PrivateName, symbol: Symbol | undefined, parent: Symbol | undefined) => Symbol | undefined): Symbol | undefined {
             if (isExportsOrModuleExportsOrAlias(file, e)) {
                 return file.symbol;
             }
             else if (isIdentifier(e)) {
                 return action(e, lookupSymbolForPropertyAccess(e), parent);
             }
             else {
-                const s = forEachIdentifierInEntityName(e.expression, parent, action);
+                const s = forEachIdentifierOrPrivateNameInEntityName(e.expression, parent, action);
                 if (!s || !s.exports) return Debug.fail();
                 return action(e.name, s.exports.get(e.name.escapedText), s);
             }
@@ -3134,8 +3137,7 @@ namespace ts {
             // A ClassDeclaration is ES6 syntax.
             transformFlags = subtreeFlags | TransformFlags.AssertES2015;
 
-            // A class with a parameter property assignment, property initializer, computed property name, or decorator is
-            // TypeScript syntax.
+            // A class with a parameter property assignment or decorator is TypeScript syntax.
             // An exported declaration may be TypeScript syntax, but is handled by the visitor
             // for a namespace declaration.
             if ((subtreeFlags & TransformFlags.ContainsTypeScriptClassSyntax)
@@ -3158,8 +3160,7 @@ namespace ts {
         // A ClassExpression is ES6 syntax.
         let transformFlags = subtreeFlags | TransformFlags.AssertES2015;
 
-        // A class with a parameter property assignment, property initializer, or decorator is
-        // TypeScript syntax.
+        // A class with a parameter property assignment or decorator is TypeScript syntax.
         if (subtreeFlags & TransformFlags.ContainsTypeScriptClassSyntax
             || node.typeParameters) {
             transformFlags |= TransformFlags.AssertTypeScript;
@@ -3255,7 +3256,6 @@ namespace ts {
             || hasModifier(node, ModifierFlags.TypeScriptModifier)
             || node.typeParameters
             || node.type
-            || (node.name && isComputedPropertyName(node.name)) // While computed method names aren't typescript, the TS transform must visit them to emit property declarations correctly
             || !node.body) {
             transformFlags |= TransformFlags.AssertTypeScript;
         }
@@ -3286,7 +3286,6 @@ namespace ts {
         if (node.decorators
             || hasModifier(node, ModifierFlags.TypeScriptModifier)
             || node.type
-            || (node.name && isComputedPropertyName(node.name)) // While computed accessor names aren't typescript, the TS transform must visit them to emit property declarations correctly
             || !node.body) {
             transformFlags |= TransformFlags.AssertTypeScript;
         }
@@ -3301,12 +3300,16 @@ namespace ts {
     }
 
     function computePropertyDeclaration(node: PropertyDeclaration, subtreeFlags: TransformFlags) {
-        // A PropertyDeclaration is TypeScript syntax.
-        let transformFlags = subtreeFlags | TransformFlags.AssertTypeScript;
+        // A PropertyDeclaration is ESnext syntax.
+        let transformFlags = subtreeFlags | TransformFlags.AssertESNext;
+
+        // Decorators, TypeScript-specific modifiers, and type annotations are TypeScript syntax.
+        if (some(node.decorators) || hasModifier(node, ModifierFlags.TypeScriptModifier) || node.type) {
+            transformFlags |= TransformFlags.AssertTypeScript;
+        }
 
-        // If the PropertyDeclaration has an initializer or a computed name, we need to inform its ancestor
-        // so that it handle the transformation.
-        if (node.initializer || isComputedPropertyName(node.name)) {
+        // Hoisted variables related to class properties should live within the TypeScript class wrapper.
+        if (isComputedPropertyName(node.name) || (hasStaticModifier(node) && node.initializer)) {
             transformFlags |= TransformFlags.ContainsTypeScriptClassSyntax;
         }
 
@@ -3707,6 +3710,8 @@ namespace ts {
                 break;
 
             case SyntaxKind.ComputedPropertyName:
+                // Computed property names are transformed by the ESNext transformer.
+                transformFlags |= TransformFlags.AssertESNext;
                 // Even though computed property names are ES6, we don't treat them as such.
                 // This is so that they can flow through PropertyName transforms unaffected.
                 // Instead, we mark the container as ES6, so that it can properly handle the transform.

src/compiler/checker.ts

@@ -14773,8 +14773,10 @@ namespace ts {
             const root = getReferenceRoot(node);
             const parent = root.parent;
             const isLengthPushOrUnshift = parent.kind === SyntaxKind.PropertyAccessExpression && (
-                (<PropertyAccessExpression>parent).name.escapedText === "length" ||
-                parent.parent.kind === SyntaxKind.CallExpression && isPushOrUnshiftIdentifier((<PropertyAccessExpression>parent).name));
+                (<PropertyAccessExpression>parent).name.escapedText === "length" || (
+                    parent.parent.kind === SyntaxKind.CallExpression
+                    && isIdentifier((parent as PropertyAccessExpression).name)
+                    && isPushOrUnshiftIdentifier((parent as PropertyAccessExpression).name as Identifier)));
             const isElementAssignment = parent.kind === SyntaxKind.ElementAccessExpression &&
                 (<ElementAccessExpression>parent).expression === root &&
                 parent.parent.kind === SyntaxKind.BinaryExpression &&
@@ -18619,7 +18621,7 @@ namespace ts {
             return checkPropertyAccessExpressionOrQualifiedName(node, node.left, node.right);
         }
 
-        function checkPropertyAccessExpressionOrQualifiedName(node: PropertyAccessExpression | QualifiedName, left: Expression | QualifiedName, right: Identifier) {
+        function checkPropertyAccessExpressionOrQualifiedName(node: PropertyAccessExpression | QualifiedName, left: Expression | QualifiedName, right: Identifier | PrivateName) {
             let propType: Type;
             const leftType = checkNonNullExpression(left);
             const parentSymbol = getNodeLinks(left).resolvedSymbol;
@@ -18637,7 +18639,7 @@ namespace ts {
             }
             if (!prop) {
                 const indexInfo = getIndexInfoOfType(apparentType, IndexKind.String);
-                if (!(indexInfo && indexInfo.type)) {
+                if (!(indexInfo && indexInfo.type) || isPrivateName(right)) {
                     if (isJSLiteralType(leftType)) {
                         return anyType;
                     }
@@ -18701,7 +18703,7 @@ namespace ts {
             return assignmentKind ? getBaseTypeOfLiteralType(flowType) : flowType;
         }
 
-        function checkPropertyNotUsedBeforeDeclaration(prop: Symbol, node: PropertyAccessExpression | QualifiedName, right: Identifier): void {
+        function checkPropertyNotUsedBeforeDeclaration(prop: Symbol, node: PropertyAccessExpression | QualifiedName, right: Identifier | PrivateName): void {
             const { valueDeclaration } = prop;
             if (!valueDeclaration) {
                 return;
@@ -18771,7 +18773,7 @@ namespace ts {
             return getIntersectionType(x);
         }
 
-        function reportNonexistentProperty(propNode: Identifier, containingType: Type) {
+        function reportNonexistentProperty(propNode: Identifier | PrivateName, containingType: Type) {
             let errorInfo: DiagnosticMessageChain | undefined;
             let relatedInfo: Diagnostic | undefined;
             if (containingType.flags & TypeFlags.Union && !(containingType.flags & TypeFlags.Primitive)) {
@@ -18814,11 +18816,11 @@ namespace ts {
             return prop !== undefined && prop.valueDeclaration && hasModifier(prop.valueDeclaration, ModifierFlags.Static);
         }
 
-        function getSuggestedSymbolForNonexistentProperty(name: Identifier | string, containingType: Type): Symbol | undefined {
+        function getSuggestedSymbolForNonexistentProperty(name: Identifier | PrivateName | string, containingType: Type): Symbol | undefined {
             return getSpellingSuggestionForName(isString(name) ? name : idText(name), getPropertiesOfType(containingType), SymbolFlags.Value);
         }
 
-        function getSuggestionForNonexistentProperty(name: Identifier | string, containingType: Type): string | undefined {
+        function getSuggestionForNonexistentProperty(name: Identifier | PrivateName | string, containingType: Type): string | undefined {
             const suggestion = getSuggestedSymbolForNonexistentProperty(name, containingType);
             return suggestion && symbolName(suggestion);
         }
@@ -22640,6 +22642,9 @@ namespace ts {
             checkGrammarDecoratorsAndModifiers(node);
 
             checkVariableLikeDeclaration(node);
+            if (node.name && isIdentifier(node.name) && node.name.originalKeywordKind === SyntaxKind.PrivateName) {
+                error(node, Diagnostics.Private_names_cannot_be_used_as_parameters);
+            }
             const func = getContainingFunction(node)!;
             if (hasModifier(node, ModifierFlags.ParameterPropertyModifier)) {
                 if (!(func.kind === SyntaxKind.Constructor && nodeIsPresent(func.body))) {
@@ -24287,9 +24292,9 @@ namespace ts {
             }
         }
 
-        function getIdentifierFromEntityNameExpression(node: Identifier | PropertyAccessExpression): Identifier;
-        function getIdentifierFromEntityNameExpression(node: Expression): Identifier | undefined;
-        function getIdentifierFromEntityNameExpression(node: Expression): Identifier | undefined {
+        function getIdentifierFromEntityNameExpression(node: Identifier | PropertyAccessExpression): Identifier | PrivateName;
+        function getIdentifierFromEntityNameExpression(node: Expression): Identifier | PrivateName | undefined;
+        function getIdentifierFromEntityNameExpression(node: Expression): Identifier | PrivateName | undefined {
             switch (node.kind) {
                 case SyntaxKind.Identifier:
                     return node as Identifier;
@@ -30141,6 +30146,10 @@ namespace ts {
                 checkESModuleMarker(node.name);
             }
 
+            if (isIdentifier(node.name) && node.name.originalKeywordKind === SyntaxKind.PrivateName) {
+                return grammarErrorOnNode(node.name, Diagnostics.Private_names_are_not_allowed_in_variable_declarations);
+            }
+
             const checkLetConstNames = (isLet(node) || isVarConst(node));
 
             // 1. LexicalDeclaration : LetOrConst BindingList ;

src/compiler/diagnosticMessages.json

@@ -4262,6 +4262,14 @@
         "category": "Error",
         "code": 18003
     },
+    "Private names are not allowed in variable declarations.": {
+        "category": "Error",
+        "code": 18004
+    },
+    "Private names cannot be used as parameters": {
+        "category": "Error",
+        "code": 18005
+    },
 
     "File is a CommonJS module; it may be converted to an ES6 module.": {
         "category": "Suggestion",

src/compiler/emitter.ts

@@ -620,6 +620,10 @@ namespace ts {
                     case SyntaxKind.Identifier:
                         return emitIdentifier(<Identifier>node);
 
+                    // PrivateNames
+                    case SyntaxKind.PrivateName:
+                        return emitPrivateName(node as PrivateName);
+
                     // Parse tree nodes
 
                     // Names
@@ -889,6 +893,10 @@ namespace ts {
                     case SyntaxKind.Identifier:
                         return emitIdentifier(<Identifier>node);
 
+                    // Private Names
+                    case SyntaxKind.PrivateName:
+                        return emitPrivateName(node as PrivateName);
+
                     // Reserved words
                     case SyntaxKind.FalseKeyword:
                     case SyntaxKind.NullKeyword:
@@ -1078,6 +1086,12 @@ namespace ts {
             emitList(node, node.typeArguments, ListFormat.TypeParameters); // Call emitList directly since it could be an array of TypeParameterDeclarations _or_ type arguments
         }
 
+        function emitPrivateName(node: PrivateName) {
+            const writeText = node.symbol ? writeSymbol : write;
+            writeText(getTextOfNode(node, /*includeTrivia*/ false), node.symbol);
+            emitList(node, /*typeArguments*/ undefined, ListFormat.TypeParameters); // Call emitList directly since it could be an array of TypeParameterDeclarations _or_ type arguments
+        }
+
         //
         // Names
         //
@@ -3320,7 +3334,7 @@ namespace ts {
         function getLiteralTextOfNode(node: LiteralLikeNode, neverAsciiEscape: boolean | undefined): string {
             if (node.kind === SyntaxKind.StringLiteral && (<StringLiteral>node).textSourceNode) {
                 const textSourceNode = (<StringLiteral>node).textSourceNode!;
-                if (isIdentifier(textSourceNode)) {
+                if (isIdentifierOrPrivateName(textSourceNode)) {
                     return neverAsciiEscape || (getEmitFlags(node) & EmitFlags.NoAsciiEscaping) ?
                         `"${escapeString(getTextOfNode(textSourceNode))}"` :
                         `"${escapeNonAsciiString(getTextOfNode(textSourceNode))}"`;