Merge branch 'master' of https://github.com/rollup/rollup

src/Module.js

@@ -50,6 +50,18 @@ class Id {
 	}
 }
 
+class LateBoundIdPlaceholder {
+	constructor ( module, name ) {
+		this.module = module;
+		this.name = name;
+		this.placeholder = true;
+	}
+
+	mark () {
+		throw new Error(`The imported name "${this.name}" is never exported by "${this.module.id}".`);
+	}
+}
+
 export default class Module {
 	constructor ({ id, source, ast, bundle }) {
 		this.source = source;
@@ -103,6 +115,7 @@ export default class Module {
 			}
 
 			// throw new Error( `The name "${name}" is never exported (from ${this.id})!` );
+			this.exports.define( name, new LateBoundIdPlaceholder( this, name ) );
 			return reference.call( this.exports, name );
 		};
 
@@ -288,7 +301,7 @@ export default class Module {
 			// bind the name to the other module's reference.
 			this.allExportsFrom.forEach( module => {
 				module.exports.getNames().forEach( name => {
-					if ( !this.exports.defines( name ) ) {
+					if ( name !== 'default' && !this.exports.defines( name ) ) {
 						this.exports.bind( name, module.exports.reference( name ) );
 					}
 				});

src/Scope.js

@@ -27,9 +27,23 @@ function isntReference ( id ) {
 	return !( id instanceof Reference );
 }
 
-// Prefix the argument with '_'.
-function underscorePrefix ( x ) {
-	return '_' + x;
+// Returns a function that will prefix its argument with '_'
+// and append a number if called with the same argument more than once.
+function underscorePrefix () {
+	function number ( x ) {
+		if ( !( x in map ) ) {
+			map[ x ] = 0;
+			return '';
+		}
+
+		return map[ x ]++;
+	}
+
+	var map = blank();
+
+	return function ( x ) {
+		return '_' + x + number( x );
+	}
 }
 
 // ## Scope
@@ -51,7 +65,7 @@ export default class Scope {
 	// Deconflict all names within the scope,
 	// using the given renaming function.
 	// If no function is supplied, `underscorePrefix` is used.
-	deconflict ( rename = underscorePrefix ) {
+	deconflict ( rename = underscorePrefix() ) {
 		const names = this.used;
 
 		this.ids.filter( ref => ref instanceof Reference ).forEach( ref => {
@@ -67,6 +81,7 @@ export default class Scope {
 		});
 
 		this.ids.filter( isntReference ).forEach( id => {
+			// TODO: can this be removed?
 			if ( typeof id === 'string' ) {
 				throw new Error( `Required name "${id}" is undefined!` );
 			}
@@ -139,7 +154,11 @@ export default class Scope {
 
 	// Get a reference to the identifier `name` in this scope.
 	reference ( name ) {
-		return new Reference( this, this.index( name ) );
+		if ( !( name in this.names ) ) {
+			throw new Error( `Cannot reference undefined identifier "${name}"` );
+		}
+
+		return new Reference( this, this.names[ name ] );
 	}
 
 	// Return the used names of the scope.

src/Statement.js

@@ -25,12 +25,19 @@ function isFunctionDeclaration ( node, parent ) {
 	if ( node.type === 'FunctionExpression' && parent.type === 'VariableDeclarator' ) return true;
 }
 
+// Extract the property access from a MemberExpression.
+function property ( node ) {
+	return node.name ? `.${node.name}` : `[${node.value}]`;
+}
+
+// Recursively traverse the chain of member expressions from `node`,
+// returning the access, e.g. `foo.bar[17]`
 function chainedMemberExpression ( node ) {
 	if ( node.object.type === 'MemberExpression' ) {
-		return chainedMemberExpression( node.object ) + '.' + node.property.name;
+		return chainedMemberExpression( node.object ) + property( node.property );
 	}
 
-	return node.object.name + '.' + node.property.name;
+	return node.object.name + property( node.property );
 }
 
 export default class Statement {
@@ -161,10 +168,10 @@ export default class Statement {
 		// /update expressions) need to be captured
 		let writeDepth = 0;
 
-		// Used to track
-		let topName;
-		let currentMemberExpression = null;
-		let namespace = null;
+		// Used to track and optimize lookups through namespaces.
+		let localName;        // The local name of the top-most imported namespace.
+		let topNode = null;   // The top-node of the member expression.
+		let namespace = null; // An instance of `Module`.
 
 		if ( !this.isImportDeclaration ) {
 			walk( this.node, {
@@ -184,13 +191,21 @@ export default class Statement {
 					if ( node._scope ) scope = scope.parent;
 
 					// Optimize namespace lookups, which manifest as MemberExpressions.
-					if ( node.type === 'MemberExpression' && ( !currentMemberExpression || node.object === currentMemberExpression ) ) {
-						currentMemberExpression = node;
+					if ( node.type === 'MemberExpression' && ( !topNode || node.object === topNode ) ) {
+						// Ignore anything that doesn't begin with an identifier.
+						if ( !topNode && node.object.type !== 'Identifier') return;
 
+						topNode = node;
+
+						// If we don't already have a namespace,
+						// we aren't currently exploring any chain of member expressions.
 						if ( !namespace ) {
-							topName = node.object.name;
-							const id = this.module.locals.lookup( topName );
+							localName = node.object.name;
+
+							// At first, we don't have a namespace, so we'll try to look one up.
+							const id = this.module.locals.lookup( localName );
 
+							// It only counts if it exists, is a module, and isn't external.
 							if ( !id || !id.isModule || id.isExternal ) return;
 
 							namespace = id;
@@ -225,16 +240,16 @@ export default class Statement {
 							namespace.mark();
 
 							namespace = null;
-							currentMemberExpression = null;
+							topNode = null;
 							return;
 						}
 
 						const id = namespace.exports.lookup( name );
 
-						// If the namespace doesn't define the given name,
+						// If the namespace doesn't export the given name,
 						// we can throw an error (even for nested namespaces).
 						if ( !id ) {
-							throw new Error( `Module doesn't define "${name}"!` );
+							throw new Error( `Module "${namespace.id}" doesn't export "${name}"!` );
 						}
 
 						// We can't resolve deeper. Replace the member chain.
@@ -244,18 +259,18 @@ export default class Statement {
 							}
 
 							// FIXME: do this better
-							// If we depend on this name...
-							if ( this.dependsOn[ topName ] ) {
+							// If an earlier stage detected that we depend on this name...
+							if ( this.dependsOn[ localName ] ) {
 								// ... decrement the count...
-								if ( !--this.dependsOn[ topName ] ) {
+								if ( !--this.dependsOn[ localName ] ) {
 									// ... and remove it if the count is 0.
-									delete this.dependsOn[ topName ];
+									delete this.dependsOn[ localName ];
 								}
 							}
 
-							this.namespaceReplacements.push( [ node, id ] );
+							this.namespaceReplacements.push( [ topNode, id ] );
 							namespace = null;
-							currentMemberExpression = null;
+							topNode = null;
 							return;
 						}
 
@@ -486,7 +501,8 @@ export default class Statement {
 					topLevel = false;
 
 					let newNames = blank();
-					let hasReplacements;
+					// Consider a scope to have replacements if there are any namespaceReplacements.
+					let hasReplacements = statement.namespaceReplacements.length > 0;
 
 					keys( names ).forEach( name => {
 						if ( !scope.declarations[ name ] ) {

test/form/export-all-from-internal/_expected/amd.js

@@ -2,10 +2,8 @@ define(['exports'], function (exports) { 'use strict';
 
 	const a = 1;
 	const b = 2;
-	var internal = 42;
 
 	exports.a = a;
 	exports.b = b;
-	exports['default'] = internal;
 
 });

test/form/export-all-from-internal/_expected/cjs.js

@@ -2,8 +2,6 @@
 
 const a = 1;
 const b = 2;
-var internal = 42;
 
 exports.a = a;
 exports.b = b;
-exports['default'] = internal;

test/form/export-all-from-internal/_expected/es6.js

@@ -1,6 +1,4 @@
 const a = 1;
 const b = 2;
-var internal = 42;
 
 export { a, b };
-export default internal;

test/form/export-all-from-internal/_expected/iife.js

@@ -2,10 +2,8 @@
 
 	const a = 1;
 	const b = 2;
-	var internal = 42;
 
 	exports.a = a;
 	exports.b = b;
-	exports['default'] = internal;
 
 })((this.exposedInternals = {}));

test/form/export-all-from-internal/_expected/umd.js

@@ -6,10 +6,8 @@
 
 	const a = 1;
 	const b = 2;
-	var internal = 42;
 
 	exports.a = a;
 	exports.b = b;
-	exports['default'] = internal;
 
 }));

test/function/import-of-unexported-fails/_config.js

@@ -0,0 +1,10 @@
+var assert = require( 'assert' );
+
+module.exports = {
+	description: 'marking an imported, but unexported, identifier should throw',
+
+	error: function ( err ) {
+		assert.equal( err.message.slice( 0, 50 ), 'The imported name "default" is never exported by "' );
+		assert.equal( err.message.slice( -10 ), 'empty.js".' );
+	}
+};

test/function/import-of-unexported-fails/main.js

@@ -0,0 +1,3 @@
+import a from './empty.js';
+
+a();

test/testScope.js

@@ -93,7 +93,7 @@ describe( 'Scope', function () {
 		});
 	});
 
-	it( 'dedupes-external-imports', function () {
+	it( 'cannot reference undefined names', function () {
 		var real = new Scope();
 
 		var external = real.virtual(),
@@ -104,17 +104,11 @@ describe( 'Scope', function () {
 
 		locals.bind( 'Comp', external.reference( 'Component' ) );
 
+		assert.throws( function () {
 			exports.bind( 'default', locals.reference( 'Foo' ) );
-
-		try {
-			real.deconflict();
-			assert.ok( false, 'Scope.deconflict should throw with "Foo" undefined' );
-		} catch ( ignore ) {
-			// as expected
-		}
+		}, 'Cannot reference undefined identifier "Foo"' );
 
 		locals.define( 'Foo' );
-
-		real.deconflict();
+		exports.bind( 'default', locals.reference( 'Foo' ) );
 	});
 });