Merge pull request #12608 from Microsoft/mergeMaster1201

Merge master1201

Author: mhegazy

src/compiler/binder.ts

@@ -518,7 +518,6 @@ namespace ts {
                 hasExplicitReturn = false;
                 bindChildren(node);
                 // Reset all reachability check related flags on node (for incremental scenarios)
-                // Reset all emit helper flags on node (for incremental scenarios)
                 node.flags &= ~NodeFlags.ReachabilityAndEmitFlags;
                 if (!(currentFlow.flags & FlowFlags.Unreachable) && containerFlags & ContainerFlags.IsFunctionLike && nodeIsPresent((<FunctionLikeDeclaration>node).body)) {
                     node.flags |= NodeFlags.HasImplicitReturn;
@@ -1950,9 +1949,6 @@ namespace ts {
                     return bindParameter(<ParameterDeclaration>node);
                 case SyntaxKind.VariableDeclaration:
                 case SyntaxKind.BindingElement:
-                    if ((node as BindingElement).dotDotDotToken && node.parent.kind === SyntaxKind.ObjectBindingPattern) {
-                        emitFlags |= NodeFlags.HasRestAttribute;
-                    }
                     return bindVariableDeclarationOrBindingElement(<VariableDeclaration | BindingElement>node);
                 case SyntaxKind.PropertyDeclaration:
                 case SyntaxKind.PropertySignature:
@@ -1980,7 +1976,6 @@ namespace ts {
                         }
                         root = root.parent;
                     }
-                    emitFlags |= hasRest ? NodeFlags.HasRestAttribute : NodeFlags.HasSpreadAttribute;
                     return;
 
                 case SyntaxKind.CallSignature:
@@ -2236,15 +2231,6 @@ namespace ts {
         }
 
         function bindClassLikeDeclaration(node: ClassLikeDeclaration) {
-            if (!isDeclarationFile(file) && !isInAmbientContext(node)) {
-                if (getClassExtendsHeritageClauseElement(node) !== undefined) {
-                    emitFlags |= NodeFlags.HasClassExtends;
-                }
-                if (nodeIsDecorated(node)) {
-                    emitFlags |= NodeFlags.HasDecorators;
-                }
-            }
-
             if (node.kind === SyntaxKind.ClassDeclaration) {
                 bindBlockScopedDeclaration(node, SymbolFlags.Class, SymbolFlags.ClassExcludes);
             }
@@ -2314,12 +2300,6 @@ namespace ts {
         }
 
         function bindParameter(node: ParameterDeclaration) {
-            if (!isDeclarationFile(file) &&
-                !isInAmbientContext(node) &&
-                nodeIsDecorated(node)) {
-                emitFlags |= (NodeFlags.HasDecorators | NodeFlags.HasParamDecorators);
-            }
-
             if (inStrictMode) {
                 // It is a SyntaxError if the identifier eval or arguments appears within a FormalParameterList of a
                 // strict mode FunctionLikeDeclaration or FunctionExpression(13.1)
@@ -2377,9 +2357,6 @@ namespace ts {
                 if (isAsyncFunctionLike(node)) {
                     emitFlags |= NodeFlags.HasAsyncFunctions;
                 }
-                if (nodeIsDecorated(node)) {
-                    emitFlags |= NodeFlags.HasDecorators;
-                }
             }
 
             if (currentFlow && isObjectLiteralOrClassExpressionMethod(node)) {

src/compiler/checker.ts

@@ -1625,6 +1625,12 @@ namespace ts {
                             Diagnostics.Parameter_0_of_call_signature_from_exported_interface_has_or_is_using_name_1_from_private_module_2 :
                             Diagnostics.Parameter_0_of_call_signature_from_exported_interface_has_or_is_using_private_name_1;
 
+                    case SyntaxKind.IndexSignature:
+                        // Interfaces cannot have parameter types that cannot be named
+                        return symbolAccessibilityResult.errorModuleName ?
+                            Diagnostics.Parameter_0_of_index_signature_from_exported_interface_has_or_is_using_name_1_from_private_module_2 :
+                            Diagnostics.Parameter_0_of_index_signature_from_exported_interface_has_or_is_using_private_name_1;
+
                     case SyntaxKind.MethodDeclaration:
                     case SyntaxKind.MethodSignature:
                         if (hasModifier(node.parent, ModifierFlags.Static)) {

src/compiler/declarationEmitter.ts

@@ -1027,6 +1027,10 @@
         "category": "Error",
         "code": 2342
     },
+    "This syntax requires an imported helper named '{1}', but module '{0}' has no exported member '{1}'.": {
+        "category": "Error",
+        "code": 2343
+    },
     "Type '{0}' does not satisfy the constraint '{1}'.": {
         "category": "Error",
         "code": 2344
@@ -1067,6 +1071,10 @@
         "category": "Error",
         "code": 2353
     },
+    "This syntax requires an imported helper but module '{0}' cannot be found.": {
+        "category": "Error",
+        "code": 2354
+    },
     "A function whose declared type is neither 'void' nor 'any' must return a value.": {
         "category": "Error",
         "code": 2355
@@ -2292,6 +2300,14 @@
         "category": "Message",
         "code": 4090
     },
+    "Parameter '{0}' of index signature from exported interface has or is using name '{1}' from private module '{2}'.": {
+        "category": "Error",
+        "code": 4091
+    },
+    "Parameter '{0}' of index signature from exported interface has or is using private name '{1}'.": {
+        "category": "Error",
+        "code": 4092
+    },
 
     "The current host does not support the '{0}' option.": {
         "category": "Error",

src/compiler/diagnosticMessages.json

@@ -459,7 +459,7 @@ namespace ts {
                 var t = {};
                 for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p) && e.indexOf(p) < 0)
                     t[p] = s[p];
-                if (typeof Object.getOwnPropertySymbols === "function")
+                if (s != null && typeof Object.getOwnPropertySymbols === "function")
                     for (var i = 0, p = Object.getOwnPropertySymbols(s); i < p.length; i++) if (e.indexOf(p[i]) < 0)
                         t[p[i]] = s[p[i]];
                 return t;

src/compiler/transformers/destructuring.ts

@@ -418,26 +418,20 @@ namespace ts {
         HasImplicitReturn =  1 << 7,  // If function implicitly returns on one of codepaths (initialized by binding)
         HasExplicitReturn =  1 << 8,  // If function has explicit reachable return on one of codepaths (initialized by binding)
         GlobalAugmentation = 1 << 9,  // Set if module declaration is an augmentation for the global scope
-        HasClassExtends =    1 << 10, // If the file has a non-ambient class with an extends clause in ES5 or lower (initialized by binding)
-        HasDecorators =      1 << 11, // If the file has decorators (initialized by binding)
-        HasParamDecorators = 1 << 12, // If the file has parameter decorators (initialized by binding)
-        HasAsyncFunctions =  1 << 13, // If the file has async functions (initialized by binding)
-        HasSpreadAttribute = 1 << 14, // If the file as JSX spread attributes (initialized by binding)
-        HasRestAttribute =   1 << 15, // If the file has object destructure elements
-        DisallowInContext =  1 << 16, // If node was parsed in a context where 'in-expressions' are not allowed
-        YieldContext =       1 << 17, // If node was parsed in the 'yield' context created when parsing a generator
-        DecoratorContext =   1 << 18, // If node was parsed as part of a decorator
-        AwaitContext =       1 << 19, // If node was parsed in the 'await' context created when parsing an async function
-        ThisNodeHasError =   1 << 20, // If the parser encountered an error when parsing the code that created this node
-        JavaScriptFile =     1 << 21, // If node was parsed in a JavaScript
-        ThisNodeOrAnySubNodesHasError = 1 << 22, // If this node or any of its children had an error
-        HasAggregatedChildData = 1 << 23, // If we've computed data from children and cached it in this node
+        HasAsyncFunctions =  1 << 10, // If the file has async functions (initialized by binding)
+        DisallowInContext =  1 << 11, // If node was parsed in a context where 'in-expressions' are not allowed
+        YieldContext =       1 << 12, // If node was parsed in the 'yield' context created when parsing a generator
+        DecoratorContext =   1 << 13, // If node was parsed as part of a decorator
+        AwaitContext =       1 << 14, // If node was parsed in the 'await' context created when parsing an async function
+        ThisNodeHasError =   1 << 15, // If the parser encountered an error when parsing the code that created this node
+        JavaScriptFile =     1 << 16, // If node was parsed in a JavaScript
+        ThisNodeOrAnySubNodesHasError = 1 << 17, // If this node or any of its children had an error
+        HasAggregatedChildData = 1 << 18, // If we've computed data from children and cached it in this node
 
         BlockScoped = Let | Const,
 
         ReachabilityCheckFlags = HasImplicitReturn | HasExplicitReturn,
-        EmitHelperFlags = HasClassExtends | HasDecorators | HasParamDecorators | HasAsyncFunctions | HasSpreadAttribute | HasRestAttribute,
-        ReachabilityAndEmitFlags = ReachabilityCheckFlags | EmitHelperFlags,
+        ReachabilityAndEmitFlags = ReachabilityCheckFlags | HasAsyncFunctions,
 
         // Parsing context flags
         ContextFlags = DisallowInContext | YieldContext | DecoratorContext | AwaitContext | JavaScriptFile,
@@ -3698,6 +3692,25 @@ namespace ts {
         readonly priority?: number; // Helpers with a higher priority are emitted earlier than other helpers on the node.
     }
 
+    /**
+     * Used by the checker, this enum keeps track of external emit helpers that should be type
+     * checked.
+     */
+    /* @internal */
+    export const enum ExternalEmitHelpers {
+        Extends = 1 << 0,           // __extends (used by the ES2015 class transformation)
+        Assign = 1 << 1,            // __assign (used by Jsx and ESNext object spread transformations)
+        Rest = 1 << 2,              // __rest (used by ESNext object rest transformation)
+        Decorate = 1 << 3,          // __decorate (used by TypeScript decorators transformation)
+        Metadata = 1 << 4,          // __metadata (used by TypeScript decorators transformation)
+        Param = 1 << 5,             // __param (used by TypeScript decorators transformation)
+        Awaiter = 1 << 6,           // __awaiter (used by ES2017 async functions transformation)
+        Generator = 1 << 7,         // __generator (used by ES2015 generator transformation)
+
+        FirstEmitHelper = Extends,
+        LastEmitHelper = Generator
+    }
+
     /* @internal */
     export const enum EmitContext {
         SourceFile,         // Emitting a SourceFile

src/compiler/types.ts

@@ -423,6 +423,10 @@ namespace ts {
         return false;
     }
 
+    export function isEffectiveExternalModule(node: SourceFile, compilerOptions: CompilerOptions) {
+        return isExternalModule(node) || compilerOptions.isolatedModules;
+    }
+
     export function isBlockScope(node: Node, parentNode: Node) {
         switch (node.kind) {
             case SyntaxKind.SourceFile:

src/compiler/utilities.ts

@@ -0,0 +1,17 @@
+tests/cases/compiler/declarationEmitIndexTypeNotFound.ts(3,6): error TS1023: An index signature parameter type must be 'string' or 'number'.
+tests/cases/compiler/declarationEmitIndexTypeNotFound.ts(3,13): error TS2304: Cannot find name 'TypeNotFound'.
+tests/cases/compiler/declarationEmitIndexTypeNotFound.ts(3,13): error TS4092: Parameter 'index' of index signature from exported interface has or is using private name 'TypeNotFound'.
+
+
+==== tests/cases/compiler/declarationEmitIndexTypeNotFound.ts (3 errors) ====
+    
+    export interface Test {
+        [index: TypeNotFound]: any;
+         ~~~~~
+!!! error TS1023: An index signature parameter type must be 'string' or 'number'.
+                ~~~~~~~~~~~~
+!!! error TS2304: Cannot find name 'TypeNotFound'.
+                ~~~~~~~~~~~~
+!!! error TS4092: Parameter 'index' of index signature from exported interface has or is using private name 'TypeNotFound'.
+    }
+    

tests/baselines/reference/declarationEmitIndexTypeNotFound.errors.txt

@@ -0,0 +1,9 @@
+//// [declarationEmitIndexTypeNotFound.ts]
+
+export interface Test {
+    [index: TypeNotFound]: any;
+}
+
+
+//// [declarationEmitIndexTypeNotFound.js]
+"use strict";

tests/baselines/reference/declarationEmitIndexTypeNotFound.js

@@ -1,32 +1,38 @@
-error TS2305: Module 'tslib' has no exported member '__assign'.
-error TS2305: Module 'tslib' has no exported member '__decorate'.
-error TS2305: Module 'tslib' has no exported member '__extends'.
-error TS2305: Module 'tslib' has no exported member '__metadata'.
-error TS2305: Module 'tslib' has no exported member '__param'.
-error TS2305: Module 'tslib' has no exported member '__rest'.
+tests/cases/compiler/external.ts(2,16): error TS2343: This syntax requires an imported helper named '__extends', but module 'tslib' has no exported member '__extends'.
+tests/cases/compiler/external.ts(6,1): error TS2343: This syntax requires an imported helper named '__decorate', but module 'tslib' has no exported member '__decorate'.
+tests/cases/compiler/external.ts(6,1): error TS2343: This syntax requires an imported helper named '__metadata', but module 'tslib' has no exported member '__metadata'.
+tests/cases/compiler/external.ts(8,12): error TS2343: This syntax requires an imported helper named '__param', but module 'tslib' has no exported member '__param'.
+tests/cases/compiler/external.ts(13,13): error TS2343: This syntax requires an imported helper named '__assign', but module 'tslib' has no exported member '__assign'.
+tests/cases/compiler/external.ts(14,12): error TS2343: This syntax requires an imported helper named '__rest', but module 'tslib' has no exported member '__rest'.
 
 
-!!! error TS2305: Module 'tslib' has no exported member '__assign'.
-!!! error TS2305: Module 'tslib' has no exported member '__decorate'.
-!!! error TS2305: Module 'tslib' has no exported member '__extends'.
-!!! error TS2305: Module 'tslib' has no exported member '__metadata'.
-!!! error TS2305: Module 'tslib' has no exported member '__param'.
-!!! error TS2305: Module 'tslib' has no exported member '__rest'.
-==== tests/cases/compiler/external.ts (0 errors) ====
+==== tests/cases/compiler/external.ts (6 errors) ====
     export class A { }
     export class B extends A { }
+                   ~~~~~~~~~
+!!! error TS2343: This syntax requires an imported helper named '__extends', but module 'tslib' has no exported member '__extends'.
 
     declare var dec: any;
 
     @dec
+    ~~~~
+!!! error TS2343: This syntax requires an imported helper named '__decorate', but module 'tslib' has no exported member '__decorate'.
+    ~~~~
+!!! error TS2343: This syntax requires an imported helper named '__metadata', but module 'tslib' has no exported member '__metadata'.
     class C {
         method(@dec x: number) {
+               ~~~~
+!!! error TS2343: This syntax requires an imported helper named '__param', but module 'tslib' has no exported member '__param'.
         }
     }
 
     const o = { a: 1 };
     const y = { ...o };
+                ~~~~
+!!! error TS2343: This syntax requires an imported helper named '__assign', but module 'tslib' has no exported member '__assign'.
     const { ...x } = y;
+               ~
+!!! error TS2343: This syntax requires an imported helper named '__rest', but module 'tslib' has no exported member '__rest'.
 
 ==== tests/cases/compiler/script.ts (0 errors) ====
     class A { }

tests/baselines/reference/importHelpersNoHelpers.errors.txt

@@ -1,10 +1,11 @@
-error TS2307: Cannot find module 'tslib'.
+tests/cases/compiler/external.ts(2,16): error TS2354: This syntax requires an imported helper but module 'tslib' cannot be found.
 
 
-!!! error TS2307: Cannot find module 'tslib'.
-==== tests/cases/compiler/external.ts (0 errors) ====
+==== tests/cases/compiler/external.ts (1 errors) ====
     export class A { }
     export class B extends A { }
+                   ~~~~~~~~~
+!!! error TS2354: This syntax requires an imported helper but module 'tslib' cannot be found.
 
     declare var dec: any;
 

tests/baselines/reference/importHelpersNoModule.errors.txt

@@ -103,6 +103,21 @@ function f6(s: string) {
     });
     let v = unboxify(b);
     let x: string | number | boolean = v[s];
+}
+
+declare function validate<T>(obj: { [P in keyof T]?: T[P] }): T;
+declare function clone<T>(obj: { readonly [P in keyof T]: T[P] }): T;
+declare function validateAndClone<T>(obj: { readonly [P in keyof T]?: T[P] }): T;
+
+type Foo = {
+    a?: number;
+    readonly b: string;
+}
+
+function f10(foo: Foo) {
+    let x = validate(foo);  // { a: number, readonly b: string }
+    let y = clone(foo);  // { a?: number, b: string }
+    let z = validateAndClone(foo);  // { a: number, b: string }
 }
 
 //// [isomorphicMappedTypeInference.js]
@@ -190,6 +205,11 @@ function f6(s) {
     var v = unboxify(b);
     var x = v[s];
 }
+function f10(foo) {
+    var x = validate(foo); // { a: number, readonly b: string }
+    var y = clone(foo); // { a?: number, b: string }
+    var z = validateAndClone(foo); // { a: number, b: string }
+}
 
 
 //// [isomorphicMappedTypeInference.d.ts]
@@ -220,3 +240,17 @@ declare function makeDictionary<T>(obj: {
     [x: string]: T;
 };
 declare function f6(s: string): void;
+declare function validate<T>(obj: {
+    [P in keyof T]?: T[P];
+}): T;
+declare function clone<T>(obj: {
+    readonly [P in keyof T]: T[P];
+}): T;
+declare function validateAndClone<T>(obj: {
+    readonly [P in keyof T]?: T[P];
+}): T;
+declare type Foo = {
+    a?: number;
+    readonly b: string;
+};
+declare function f10(foo: Foo): void;