virtual scopes optionally inherit the parent scope

* locals should inherit references to global variables
* exports on the other hand should not

src/ExternalModule.js

@@ -22,7 +22,7 @@ export default class ExternalModule {
 		this.needsNamed = false;
 		this.needsAll = false;
 
-		this.exports = bundle.scope.virtual();
+		this.exports = bundle.scope.virtual( false );
 
 		const { reference } = this.exports;
 

src/Module.js

@@ -51,14 +51,16 @@ export default class Module {
 		this.resolvedIds = blank();
 
 		// Virtual scopes for the local and exported names.
-		this.locals = bundle.scope.virtual();
-		this.exports = bundle.scope.virtual();
+		this.locals = bundle.scope.virtual( true );
+		this.exports = bundle.scope.virtual( false );
 
 		const { reference, inScope } = this.exports;
 
 		this.exports.reference = name => {
 			// If we have it, grab it.
-			if ( inScope.call( this.exports, name ) ) return reference.call( this.exports, name );
+			if ( inScope.call( this.exports, name ) ) {
+				return reference.call( this.exports, name );
+			}
 
 			// ... otherwise search exportAlls.
 			for ( const module of this.exportAlls ) {
@@ -67,7 +69,8 @@ export default class Module {
 				}
 			}
 
-			throw new Error( `The name ${name} is never exported!` );
+			// throw new Error( `The name "${name}" is never exported (from ${this.id})!` );
+			return reference.call( this.exports, name );
 		};
 
 		this.exports.inScope = name => {
@@ -185,7 +188,7 @@ export default class Module {
 					name = declaration.id.name;
 				}
 
-				this.locals.define({
+				this.locals.define( name, {
 					originalName: name,
 					name,
 

src/Scope.js

@@ -143,11 +143,10 @@ export default class Scope {
 	}
 
 	// Create and return a virtual `Scope` instance, bound to
-	// the actual scope of `this`.
-	virtual () {
-		const scope = new Scope();
+	// the actual scope of `this`, optionally inherit the parent scope.
+	virtual ( inheritParent ) {
+		const scope = new Scope( inheritParent ? this.parent : null );
 		scope.ids = this.ids;
-		scope.parent = this.parent;
 		return scope;
 	}
 }