More tests pass

* Move `name` definition closer to usage.
* Fixed mistake where `locals` should have been `exports`

src/ExternalModule.js

@@ -11,8 +11,6 @@ export default class ExternalModule {
 		this.isExternal = true;
 		this.importedByBundle = [];
 
-		this.needsDefault = false;
-
 		// Invariant: needsNamed and needsAll are never both true at once.
 		// Because an import with both a namespace and named import is invalid:
 		//
@@ -21,21 +19,17 @@ export default class ExternalModule {
 		this.needsNamed = false;
 		this.needsAll = false;
 
-		bundle.scope.define( this.originalName, this );
 		this.exports = bundle.scope.virtual();
 
-		const { lookup, reference } = this.exports;
+		const { reference } = this.exports;
 
 		// Override reference.
 		this.exports.reference = name => {
-			if ( name === 'default' ) {
-				this.needsDefault = true;
-				return bundle.scope.reference( this.originalName );
+			if ( name !== 'default' ) {
+				this.needsNamed = true;
 			}
 
 			if ( !this.exports.defines( name ) ) {
-				this.needsNamed = true;
-
 				this.exports.define( name, {
 					originalName: name,
 					name,
@@ -46,14 +40,5 @@ export default class ExternalModule {
 
 			return reference.call( this.exports, name );
 		};
-
-		// Override lookup.
-		this.exports.lookup = name => {
-			if ( name === 'default' ) {
-				return this;
-			}
-
-			return lookup.call( this.exports, name );
-		};
 	}
 }

src/Module.js

@@ -14,7 +14,7 @@ function isEmptyExportedVarDeclaration ( node, exports, toExport ) {
 
 	const id = exports.lookup( name );
 
-	return !~toExport.indexOf( id.name );
+	return id.name in toExport;
 }
 
 function removeSourceMappingURLComments ( source, magicString ) {
@@ -172,7 +172,6 @@ export default class Module {
 			const isDefault = specifier.type === 'ImportDefaultSpecifier';
 			const isNamespace = specifier.type === 'ImportNamespaceSpecifier';
 
-			const name = isDefault ? 'default' : specifier.imported.name;
 			const localName = specifier.local.name;
 
 			if ( this.locals.defines( localName ) ) {
@@ -186,6 +185,8 @@ export default class Module {
 				// If it's a namespace import, we bind the localName to the module itself.
 				this.locals.bind( localName, module );
 			} else {
+				const name = isDefault ? 'default' : specifier.imported.name;
+
 				this.locals.bind( localName, module.exports.reference( name ) );
 
 				// For compliance with earlier Rollup versions.
@@ -296,7 +297,7 @@ export default class Module {
 					statement.node.specifiers.forEach( specifier => {
 						let name = specifier.exported.name;
 
-						let id = this.locals.lookup( name );
+						let id = this.exports.lookup( name );
 
 						addDependency( strongDependencies, id );
 					});
@@ -534,10 +535,10 @@ export default class Module {
 					.forEach( name => {
 						const id = this.locals.lookup( name );
 
-						// HACK: We check that `id` isn't its own module,
-						// since that is the case for external defaults.
-						if ( id.module && id !== id.module && id.module.isExternal ) {
-							replacements[ name ] = `${id.module.name}.${id.originalName}`;
+						if ( id.module && id.module.isExternal ) {
+							replacements[ name ] = id.originalName === 'default' ?
+								`${id.module.name}['default']` :
+								`${id.module.name}.${id.originalName}`;
 						}
 					});
 			}
@@ -549,7 +550,7 @@ export default class Module {
 
 					if ( toExport[ bundleName ] ) {
 						bundleExports[ name ] = replacements[ name ] = toExport[ bundleName ];
-					} else if ( bundleName !== name ) { // TODO weird structure
+					} else if ( bundleName !== name && !replacements[ name ] ) { // TODO weird structure
 						replacements[ name ] = bundleName;
 					}
 				});

src/finalisers/es6.js

@@ -19,8 +19,10 @@ export default function es6 ( bundle, magicString ) {
 		.map( module => {
 			const specifiers = [];
 
-			if ( module.needsDefault ) {
-				specifiers.push( module.exports.lookup( 'default' ).name );
+			const id = module.exports.lookup( 'default' );
+
+			if ( id ) {
+				specifiers.push( id.name );
 			}
 
 			if ( module.needsAll ) {

src/finalisers/shared/getInteropBlock.js

@@ -1,7 +1,7 @@
 export default function getInteropBlock ( bundle ) {
 	return bundle.externalModules
 		.map( module => {
-			if ( !module.needsDefault ) return;
+			if ( !module.exports.inScope( 'default' ) ) return;
 
 			if ( module.needsNamed ) {
 				return `var ${module.name}__default = 'default' in ${module.name} ? ${module.name}['default'] : ${module.name};`;