Merge pull request #5588 from Microsoft/reexport-default-export

Reexport default export

src/compiler/checker.ts

@@ -486,9 +486,19 @@ namespace ts {
                         if (location.kind === SyntaxKind.SourceFile ||
                             (location.kind === SyntaxKind.ModuleDeclaration && (<ModuleDeclaration>location).name.kind === SyntaxKind.StringLiteral)) {
 
-                            // It's an external module. Because of module/namespace merging, a module's exports are in scope,
+                            // It's an external module. First see if the module has an export default and if the local
-                            // yet we never want to treat an export specifier as putting a member in scope. Therefore,
+                            // name of that export default matches.
-                            // if the name we find is purely an export specifier, it is not actually considered in scope.
+                            if (result = moduleExports["default"]) {
+                                const localSymbol = getLocalSymbolForExportDefault(result);
+                                if (localSymbol && (result.flags & meaning) && localSymbol.name === name) {
+                                    break loop;
+                                }
+                                result = undefined;
+                            }
+
+                            // Because of module/namespace merging, a module's exports are in scope,
+                            // yet we never want to treat an export specifier as putting a member in scope. 
+                            // Therefore, if the name we find is purely an export specifier, it is not actually considered in scope.
                             // Two things to note about this:
                             //     1. We have to check this without calling getSymbol. The problem with calling getSymbol
                             //        on an export specifier is that it might find the export specifier itself, and try to
@@ -502,13 +512,6 @@ namespace ts {
                                 getDeclarationOfKind(moduleExports[name], SyntaxKind.ExportSpecifier)) {
                                 break;
                             }
-
-                            result = moduleExports["default"];
-                            const localSymbol = getLocalSymbolForExportDefault(result);
-                            if (result && localSymbol && (result.flags & meaning) && localSymbol.name === name) {
-                                break loop;
-                            }
-                            result = undefined;
                         }
 
                         if (result = getSymbol(moduleExports, name, meaning & SymbolFlags.ModuleMember)) {
@@ -4201,12 +4204,12 @@ namespace ts {
                 // We only support expressions that are simple qualified names. For other expressions this produces undefined.
                 const typeNameOrExpression = node.kind === SyntaxKind.TypeReference ? (<TypeReferenceNode>node).typeName :
                     isSupportedExpressionWithTypeArguments(<ExpressionWithTypeArguments>node) ? (<ExpressionWithTypeArguments>node).expression :
-                    undefined;
+                        undefined;
                 const symbol = typeNameOrExpression && resolveEntityName(typeNameOrExpression, SymbolFlags.Type) || unknownSymbol;
                 const type = symbol === unknownSymbol ? unknownType :
                     symbol.flags & (SymbolFlags.Class | SymbolFlags.Interface) ? getTypeFromClassOrInterfaceReference(node, symbol) :
-                    symbol.flags & SymbolFlags.TypeAlias ? getTypeFromTypeAliasReference(node, symbol) :
+                        symbol.flags & SymbolFlags.TypeAlias ? getTypeFromTypeAliasReference(node, symbol) :
-                    getTypeFromNonGenericTypeReference(node, symbol);
+                            getTypeFromNonGenericTypeReference(node, symbol);
                 // Cache both the resolved symbol and the resolved type. The resolved symbol is needed in when we check the
                 // type reference in checkTypeReferenceOrExpressionWithTypeArguments.
                 links.resolvedSymbol = symbol;
@@ -11446,7 +11449,7 @@ namespace ts {
 
             // Abstract methods can't have an implementation -- in particular, they don't need one.
             if (!isExportSymbolInsideModule && lastSeenNonAmbientDeclaration && !lastSeenNonAmbientDeclaration.body &&
-                !(lastSeenNonAmbientDeclaration.flags & NodeFlags.Abstract) ) {
+                !(lastSeenNonAmbientDeclaration.flags & NodeFlags.Abstract)) {
                 reportImplementationExpectedError(lastSeenNonAmbientDeclaration);
             }
 
@@ -14380,8 +14383,8 @@ namespace ts {
                             if (className) {
                                 copySymbol(location.symbol, meaning);
                             }
-                            // fall through; this fall-through is necessary because we would like to handle
+                        // fall through; this fall-through is necessary because we would like to handle
-                            // type parameter inside class expression similar to how we handle it in classDeclaration and interface Declaration
+                        // type parameter inside class expression similar to how we handle it in classDeclaration and interface Declaration
                         case SyntaxKind.ClassDeclaration:
                         case SyntaxKind.InterfaceDeclaration:
                             // If we didn't come from static member of class or interface,
@@ -14537,8 +14540,8 @@ namespace ts {
                 return resolveEntityName(<EntityName>entityName, meaning);
             }
             else if ((entityName.parent.kind === SyntaxKind.JsxOpeningElement) ||
-                     (entityName.parent.kind === SyntaxKind.JsxSelfClosingElement) ||
+                (entityName.parent.kind === SyntaxKind.JsxSelfClosingElement) ||
-                     (entityName.parent.kind === SyntaxKind.JsxClosingElement)) {
+                (entityName.parent.kind === SyntaxKind.JsxClosingElement)) {
                 return getJsxElementTagSymbol(<JsxOpeningLikeElement>entityName.parent);
             }
             else if (isExpression(entityName)) {
@@ -14605,8 +14608,8 @@ namespace ts {
                         : getSymbolOfPartOfRightHandSideOfImportEquals(<Identifier>node);
                 }
                 else if (node.parent.kind === SyntaxKind.BindingElement &&
-                        node.parent.parent.kind === SyntaxKind.ObjectBindingPattern &&
+                    node.parent.parent.kind === SyntaxKind.ObjectBindingPattern &&
-                        node === (<BindingElement>node.parent).propertyName) {
+                    node === (<BindingElement>node.parent).propertyName) {
                     const typeOfPattern = getTypeOfNode(node.parent.parent);
                     const propertyDeclaration = typeOfPattern && getPropertyOfType(typeOfPattern, (<Identifier>node).text);
 
@@ -14643,7 +14646,7 @@ namespace ts {
                             (<ImportDeclaration>node.parent).moduleSpecifier === node)) {
                         return resolveExternalModuleName(node, <LiteralExpression>node);
                     }
-                    // Fall through
+                // Fall through
 
                 case SyntaxKind.NumericLiteral:
                     // index access
@@ -14839,7 +14842,7 @@ namespace ts {
                 if (links.isNestedRedeclaration === undefined) {
                     const container = getEnclosingBlockScopeContainer(symbol.valueDeclaration);
                     links.isNestedRedeclaration = isStatementWithLocals(container) &&
-                    !!resolveName(container.parent, symbol.name, SymbolFlags.Value, /*nameNotFoundMessage*/ undefined, /*nameArg*/ undefined);
+                        !!resolveName(container.parent, symbol.name, SymbolFlags.Value, /*nameNotFoundMessage*/ undefined, /*nameArg*/ undefined);
                 }
                 return links.isNestedRedeclaration;
             }

tests/baselines/reference/reExportDefaultExport.js

@@ -0,0 +1,27 @@
+//// [tests/cases/conformance/es6/modules/reExportDefaultExport.ts] ////
+
+//// [m1.ts]
+
+export default function f() {
+}
+export {f};
+
+
+//// [m2.ts]
+import foo from "./m1";
+import {f} from "./m1";
+
+f();
+foo();
+
+//// [m1.js]
+function f() {
+}
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = f;
+exports.f = f;
+//// [m2.js]
+var m1_1 = require("./m1");
+var m1_2 = require("./m1");
+m1_2.f();
+m1_1.default();

tests/baselines/reference/reExportDefaultExport.symbols

@@ -0,0 +1,22 @@
+=== tests/cases/conformance/es6/modules/m1.ts ===
+
+export default function f() {
+>f : Symbol(f, Decl(m1.ts, 0, 0))
+}
+export {f};
+>f : Symbol(f, Decl(m1.ts, 3, 8))
+
+
+=== tests/cases/conformance/es6/modules/m2.ts ===
+import foo from "./m1";
+>foo : Symbol(foo, Decl(m2.ts, 0, 6))
+
+import {f} from "./m1";
+>f : Symbol(f, Decl(m2.ts, 1, 8))
+
+f();
+>f : Symbol(f, Decl(m2.ts, 1, 8))
+
+foo();
+>foo : Symbol(foo, Decl(m2.ts, 0, 6))
+

tests/baselines/reference/reExportDefaultExport.types

@@ -0,0 +1,24 @@
+=== tests/cases/conformance/es6/modules/m1.ts ===
+
+export default function f() {
+>f : () => void
+}
+export {f};
+>f : () => void
+
+
+=== tests/cases/conformance/es6/modules/m2.ts ===
+import foo from "./m1";
+>foo : () => void
+
+import {f} from "./m1";
+>f : () => void
+
+f();
+>f() : void
+>f : () => void
+
+foo();
+>foo() : void
+>foo : () => void
+

tests/cases/conformance/es6/modules/reExportDefaultExport.ts

@@ -0,0 +1,15 @@
+// @module: commonjs
+// @target: ES5
+
+// @filename: m1.ts
+export default function f() {
+}
+export {f};
+
+
+// @filename: m2.ts
+import foo from "./m1";
+import {f} from "./m1";
+
+f();
+foo();