Properly deconflict ids ids of default exports that have been reassig…

…ned (#2502)

src/Module.ts

@@ -7,8 +7,6 @@ import ExportDefaultDeclaration, {
 	isExportDefaultDeclaration
 } from './ast/nodes/ExportDefaultDeclaration';
 import ExportNamedDeclaration from './ast/nodes/ExportNamedDeclaration';
-import FunctionDeclaration from './ast/nodes/FunctionDeclaration';
-import Identifier from './ast/nodes/Identifier';
 import Import from './ast/nodes/Import';
 import ImportDeclaration from './ast/nodes/ImportDeclaration';
 import ImportSpecifier from './ast/nodes/ImportSpecifier';
@@ -366,10 +364,6 @@ export default class Module {
 			// export default function foo () {}
 			// export default foo;
 			// export default 42;
-			const identifier =
-				((<FunctionDeclaration>node.declaration).id &&
-					(<FunctionDeclaration>node.declaration).id.name) ||
-				(<Identifier>node.declaration).name;
 			if (this.exports.default) {
 				this.error(
 					{
@@ -382,7 +376,7 @@ export default class Module {
 
 			this.exports.default = {
 				localName: 'default',
-				identifier,
+				identifier: node.variable.getOriginalVariableName(),
 				node
 			};
 		} else if ((<ExportNamedDeclaration>node).declaration) {

src/ast/nodes/ExportDefaultDeclaration.ts

@@ -8,7 +8,7 @@ import {
 import ExportDefaultVariable from '../variables/ExportDefaultVariable';
 import ClassDeclaration, { isClassDeclaration } from './ClassDeclaration';
 import FunctionDeclaration, { isFunctionDeclaration } from './FunctionDeclaration';
-import Identifier, { isIdentifier } from './Identifier';
+import Identifier from './Identifier';
 import * as NodeType from './NodeType';
 import { ExpressionNode, Node, NodeBase } from './shared/Node';
 
@@ -44,19 +44,6 @@ export default class ExportDefaultDeclaration extends NodeBase {
 	variable: ExportDefaultVariable;
 	private declarationName: string;
 
-	bind() {
-		super.bind();
-		if (
-			this.declarationName &&
-			// Do not set it for Class and FunctionExpressions otherwise they get treeshaken away
-			(isFunctionDeclaration(this.declaration) ||
-				isClassDeclaration(this.declaration) ||
-				isIdentifier(this.declaration))
-		) {
-			this.variable.setOriginalVariable(this.scope.findVariable(this.declarationName));
-		}
-	}
-
 	initialise() {
 		this.included = false;
 		this.declarationName =

src/ast/variables/ExportDefaultVariable.ts

@@ -16,7 +16,7 @@ export default class ExportDefaultVariable extends LocalVariable {
 	hasId: boolean;
 
 	// Not initialised during construction
-	private original: Variable | null = null;
+	private originalId: Identifier | null = null;
 
 	constructor(
 		name: string,
@@ -29,37 +29,37 @@ export default class ExportDefaultVariable extends LocalVariable {
 			exportDefaultDeclaration.declaration,
 			deoptimizationTracker
 		);
-		this.hasId =
-			(exportDefaultDeclaration.declaration.type === NodeType.FunctionDeclaration ||
-				exportDefaultDeclaration.declaration.type === NodeType.ClassDeclaration) &&
-			!!(<FunctionDeclaration | ClassDeclaration>exportDefaultDeclaration.declaration).id;
+		const declaration = exportDefaultDeclaration.declaration;
+		if (
+			(declaration.type === NodeType.FunctionDeclaration ||
+				declaration.type === NodeType.ClassDeclaration) &&
+			(<FunctionDeclaration | ClassDeclaration>declaration).id
+		) {
+			this.hasId = true;
+			this.originalId = (<FunctionDeclaration | ClassDeclaration>declaration).id;
+		} else if (declaration.type === NodeType.Identifier) {
+			this.originalId = <Identifier>declaration;
+		}
 	}
 
 	addReference(identifier: Identifier) {
 		if (!this.hasId) {
 			this.name = identifier.name;
-			if (this.original !== null) {
-				this.original.addReference(identifier);
-			}
 		}
 	}
 
 	getName(reset?: boolean) {
 		if (!reset && this.safeName) return this.safeName;
-		if (this.original !== null && !this.original.isReassigned) return this.original.getName();
+		if (this.referencesOriginal()) return this.originalId.variable.getName();
 		return this.name;
 	}
 
 	referencesOriginal() {
-		return this.original && !this.original.isReassigned;
-	}
-
-	getOriginalVariableName() {
-		return this.original && this.original.getName();
+		return this.originalId && (this.hasId || !this.originalId.variable.isReassigned);
 	}
 
-	setOriginalVariable(original: Variable) {
-		this.original = original;
+	getOriginalVariableName(): string | null {
+		return (this.originalId && this.originalId.name) || null;
 	}
 }
 

test/function/samples/deconflict-ids/_config.js

@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'deconflicts reassigned ids'
+};

test/function/samples/deconflict-ids/conflict1.js

@@ -0,0 +1,3 @@
+function foo(){
+	throw new Error('Wrong foo function referenced.')
+}

test/function/samples/deconflict-ids/conflict2.js

@@ -0,0 +1,3 @@
+function foo(){
+	throw new Error('Wrong foo function referenced.')
+}

test/function/samples/deconflict-ids/main.js

@@ -0,0 +1,5 @@
+import './conflict1.js';
+import './conflict2.js';
+import foo from './used.js';
+
+assert.equal(foo(1), 2);

test/function/samples/deconflict-ids/used.js

@@ -0,0 +1,6 @@
+export default function foo() {
+	foo = function(x){
+		return x + 1;
+	};
+	return foo.apply(this, arguments);
+}