feat: support external star exports on namespace objects

src/Module.ts

@@ -100,9 +100,9 @@ export interface AstContext {
 	getModuleName: () => string;
 	getReexports: () => string[];
 	importDescriptions: { [name: string]: ImportDescription };
+	includeAndGetReexportedExternalNamespaces: () => ExternalVariable[];
 	includeDynamicImport: (node: ImportExpression) => void;
 	includeVariable: (context: InclusionContext, variable: Variable) => void;
-	isCrossChunkImport: (importDescription: ImportDescription) => boolean;
 	magicString: MagicString;
 	module: Module; // not to be used for tree-shaking
 	moduleContext: string;
@@ -198,7 +198,6 @@ export default class Module {
 	chunkName: string | null = null;
 	code!: string;
 	comments: CommentDescription[] = [];
-	customTransformCache!: boolean;
 	dependencies = new Set<Module | ExternalModule>();
 	dynamicallyImportedBy: Module[] = [];
 	dynamicDependencies = new Set<Module | ExternalModule>();
@@ -208,11 +207,9 @@ export default class Module {
 	}[] = [];
 	excludeFromSourcemap: boolean;
 	execIndex = Infinity;
-	exportAllModules: (Module | ExternalModule)[] = [];
 	exportAllSources = new Set<string>();
 	exports: { [name: string]: ExportDescription } = Object.create(null);
 	exportsAll: { [name: string]: string } = Object.create(null);
-	exportShimVariable: ExportShimVariable = new ExportShimVariable(this);
 	facadeChunk: Chunk | null = null;
 	id: string;
 	importDescriptions: { [name: string]: ImportDescription } = Object.create(null);
@@ -240,8 +237,11 @@ export default class Module {
 	private ast!: Program;
 	private astContext!: AstContext;
 	private context: string;
+	private customTransformCache!: boolean;
 	private defaultExport: ExportDefaultVariable | null | undefined = null;
 	private esTreeAst!: acorn.Node;
+	private exportAllModules: (Module | ExternalModule)[] = [];
+	private exportShimVariable: ExportShimVariable = new ExportShimVariable(this);
 	private graph: Graph;
 	private magicString!: MagicString;
 	private namespaceVariable: NamespaceVariable | null = null;
@@ -700,10 +700,11 @@ export default class Module {
 			getModuleName: this.basename.bind(this),
 			getReexports: this.getReexports.bind(this),
 			importDescriptions: this.importDescriptions,
+			includeAndGetReexportedExternalNamespaces: this.includeAndGetReexportedExternalNamespaces.bind(
+				this
+			),
 			includeDynamicImport: this.includeDynamicImport.bind(this),
 			includeVariable: this.includeVariable.bind(this),
-			isCrossChunkImport: importDescription =>
-				(importDescription.module as Module).chunk !== this.chunk,
 			magicString: this.magicString,
 			module: this,
 			moduleContext: this.context,
@@ -864,18 +865,6 @@ export default class Module {
 		const source = node.source.value;
 		this.sources.add(source);
 		for (const specifier of node.specifiers) {
-			const localName = specifier.local.name;
-
-			if (this.importDescriptions[localName]) {
-				return this.error(
-					{
-						code: 'DUPLICATE_IMPORT',
-						message: `Duplicated import '${localName}'`
-					},
-					specifier.start
-				);
-			}
-
 			const isDefault = specifier.type === NodeType.ImportDefaultSpecifier;
 			const isNamespace = specifier.type === NodeType.ImportNamespaceSpecifier;
 
@@ -884,7 +873,7 @@ export default class Module {
 				: isNamespace
 				? '*'
 				: (specifier as ImportSpecifier).imported.name;
-			this.importDescriptions[localName] = {
+			this.importDescriptions[specifier.local.name] = {
 				module: null as any, // filled in later
 				name,
 				source,
@@ -907,6 +896,19 @@ export default class Module {
 		}
 	}
 
+	private includeAndGetReexportedExternalNamespaces(): ExternalVariable[] {
+		const reexportedExternalNamespaces: ExternalVariable[] = [];
+		for (const module of this.exportAllModules) {
+			if (module instanceof ExternalModule) {
+				const externalVariable = module.getVariableForExportName('*');
+				externalVariable.include();
+				this.imports.add(externalVariable);
+				reexportedExternalNamespaces.push(externalVariable);
+			}
+		}
+		return reexportedExternalNamespaces;
+	}
+
 	private includeDynamicImport(node: ImportExpression) {
 		const resolution = (this.dynamicImports.find(dynamicImport => dynamicImport.node === node) as {
 			resolution: string | Module | ExternalModule | undefined;
@@ -929,14 +931,12 @@ export default class Module {
 	}
 
 	private shimMissingExport(name: string): void {
-		if (!this.exports[name]) {
-			this.graph.warn({
-				code: 'SHIMMED_EXPORT',
-				exporter: relativeId(this.id),
-				exportName: name,
-				message: `Missing export "${name}" has been shimmed in module ${relativeId(this.id)}.`
-			});
-			this.exports[name] = MISSING_EXPORT_SHIM_DESCRIPTION;
-		}
+		this.graph.warn({
+			code: 'SHIMMED_EXPORT',
+			exporter: relativeId(this.id),
+			exportName: name,
+			message: `Missing export "${name}" has been shimmed in module ${relativeId(this.id)}.`
+		});
+		this.exports[name] = MISSING_EXPORT_SHIM_DESCRIPTION;
 	}
 }

src/ast/variables/NamespaceVariable.ts

@@ -4,6 +4,7 @@ import { RESERVED_NAMES } from '../../utils/reservedNames';
 import { InclusionContext } from '../ExecutionContext';
 import Identifier from '../nodes/Identifier';
 import { UNKNOWN_PATH } from '../utils/PathTracker';
+import ExternalVariable from './ExternalVariable';
 import Variable from './Variable';
 
 export default class NamespaceVariable extends Variable {
@@ -12,7 +13,7 @@ export default class NamespaceVariable extends Variable {
 	memberVariables: { [name: string]: Variable } = Object.create(null);
 	module: Module;
 
-	private containsExternalNamespace = false;
+	private reexportedExternalNamespaces: ExternalVariable[] = [];
 	private referencedEarly = false;
 	private references: Identifier[] = [];
 	private syntheticNamedExports: boolean;
@@ -41,20 +42,14 @@ export default class NamespaceVariable extends Variable {
 
 	include(context: InclusionContext) {
 		if (!this.included) {
-			if (this.containsExternalNamespace) {
-				return this.context.error({
-					code: 'NAMESPACE_CANNOT_CONTAIN_EXTERNAL',
-					id: this.module.id,
-					message: `Cannot create an explicit namespace object for module "${this.context.getModuleName()}" because it contains a reexported external namespace`
-				});
-			}
 			this.included = true;
 			for (const identifier of this.references) {
 				if (identifier.context.getModuleExecIndex() <= this.context.getModuleExecIndex()) {
 					this.referencedEarly = true;
 					break;
 				}
 			}
+			this.reexportedExternalNamespaces = this.context.includeAndGetReexportedExternalNamespaces();
 			if (this.context.preserveModules) {
 				for (const memberName of Object.keys(this.memberVariables))
 					this.memberVariables[memberName].include(context);
@@ -67,8 +62,9 @@ export default class NamespaceVariable extends Variable {
 
 	initialise() {
 		for (const name of this.context.getExports().concat(this.context.getReexports())) {
-			if (name[0] === '*' && name.length > 1) this.containsExternalNamespace = true;
-			this.memberVariables[name] = this.context.traceExport(name);
+			if (name[0] !== '*') {
+				this.memberVariables[name] = this.context.traceExport(name);
+			}
 		}
 	}
 
@@ -91,21 +87,32 @@ export default class NamespaceVariable extends Variable {
 			return `${t}${safeName}: ${original.getName()}`;
 		});
 
-		members.unshift(`${t}__proto__:${_}null`);
-
 		if (options.namespaceToStringTag) {
 			members.unshift(`${t}[Symbol.toStringTag]:${_}'Module'`);
 		}
 
-		const name = this.getName();
+		const hasExternalReexports = this.reexportedExternalNamespaces.length > 0;
+		if (!hasExternalReexports) members.unshift(`${t}__proto__:${_}null`);
+
 		let output = `{${n}${members.join(`,${n}`)}${n}}`;
-		if (this.syntheticNamedExports) {
-			output = `/*#__PURE__*/Object.assign(${output}, ${this.module.getDefaultExport().getName()})`;
+		if (hasExternalReexports || this.syntheticNamedExports) {
+			const assignmentArgs = members.length > 0 ? [output] : [];
+			if (hasExternalReexports) {
+				assignmentArgs.unshift(
+					'/*#__PURE__*/Object.create(null)',
+					...this.reexportedExternalNamespaces.map(variable => variable.getName())
+				);
+			}
+			if (this.syntheticNamedExports) {
+				assignmentArgs.push(this.module.getDefaultExport().getName());
+			}
+			output = `/*#__PURE__*/Object.assign(${assignmentArgs.join(`,${_}`)})`;
 		}
 		if (options.freeze) {
 			output = `/*#__PURE__*/Object.freeze(${output})`;
 		}
 
+		const name = this.getName();
 		output = `${options.varOrConst} ${name}${_}=${_}${output};`;
 
 		if (options.format === 'system' && this.exportName) {

test/form/samples/compact/_expected/amd.js

@@ -1,6 +1,6 @@
-define(['external'],function(x){'use strict';x=x&&Object.prototype.hasOwnProperty.call(x,'default')?x['default']:x;var self=/*#__PURE__*/Object.freeze({[Symbol.toStringTag]:'Module',__proto__:null,get default(){return foo}});console.log(self);
+define(['external'],function(x){'use strict';x=x&&Object.prototype.hasOwnProperty.call(x,'default')?x['default']:x;var self=/*#__PURE__*/Object.freeze({__proto__:null,[Symbol.toStringTag]:'Module',get default(){return foo}});console.log(self);
 function foo () {
 	console.log( x );
 }
 // trailing comment
-return foo;});
+return foo;});

test/form/samples/compact/_expected/cjs.js

@@ -1,4 +1,4 @@
-'use strict';function _interopDefault(e){return(e&&(typeof e==='object')&&'default'in e)?e['default']:e}var x=_interopDefault(require('external'));var self=/*#__PURE__*/Object.freeze({[Symbol.toStringTag]:'Module',__proto__:null,get default(){return foo}});console.log(self);
+'use strict';function _interopDefault(e){return(e&&(typeof e==='object')&&'default'in e)?e['default']:e}var x=_interopDefault(require('external'));var self=/*#__PURE__*/Object.freeze({__proto__:null,[Symbol.toStringTag]:'Module',get default(){return foo}});console.log(self);
 function foo () {
 	console.log( x );
 }

test/form/samples/compact/_expected/es.js

@@ -1,4 +1,4 @@
-import x from'external';var self=/*#__PURE__*/Object.freeze({[Symbol.toStringTag]:'Module',__proto__:null,get default(){return foo}});console.log(self);
+import x from'external';var self=/*#__PURE__*/Object.freeze({__proto__:null,[Symbol.toStringTag]:'Module',get default(){return foo}});console.log(self);
 function foo () {
 	console.log( x );
 }

test/form/samples/compact/_expected/iife.js

@@ -1,6 +1,6 @@
-var foo=(function(x){'use strict';x=x&&Object.prototype.hasOwnProperty.call(x,'default')?x['default']:x;var self=/*#__PURE__*/Object.freeze({[Symbol.toStringTag]:'Module',__proto__:null,get default(){return foo}});console.log(self);
+var foo=(function(x){'use strict';x=x&&Object.prototype.hasOwnProperty.call(x,'default')?x['default']:x;var self=/*#__PURE__*/Object.freeze({__proto__:null,[Symbol.toStringTag]:'Module',get default(){return foo}});console.log(self);
 function foo () {
 	console.log( x );
 }
 // trailing comment
-return foo;}(x));
+return foo;}(x));

test/form/samples/compact/_expected/system.js

@@ -1,4 +1,4 @@
-System.register('foo',['external'],function(exports){'use strict';var x;return{setters:[function(module){x=module.default;}],execute:function(){exports('default',foo);var self=/*#__PURE__*/Object.freeze({[Symbol.toStringTag]:'Module',__proto__:null,get default(){return foo}});console.log(self);
+System.register('foo',['external'],function(exports){'use strict';var x;return{setters:[function(module){x=module.default;}],execute:function(){exports('default',foo);var self=/*#__PURE__*/Object.freeze({__proto__:null,[Symbol.toStringTag]:'Module',get default(){return foo}});console.log(self);
 function foo () {
 	console.log( x );
 }

test/form/samples/compact/_expected/umd.js

@@ -1,6 +1,6 @@
-(function(g,f){typeof exports==='object'&&typeof module!=='undefined'?module.exports=f(require('external')):typeof define==='function'&&define.amd?define(['external'],f):(g=g||self,g.foo=f(g.x));}(this,(function(x){'use strict';x=x&&Object.prototype.hasOwnProperty.call(x,'default')?x['default']:x;var self=/*#__PURE__*/Object.freeze({[Symbol.toStringTag]:'Module',__proto__:null,get default(){return foo}});console.log(self);
+(function(g,f){typeof exports==='object'&&typeof module!=='undefined'?module.exports=f(require('external')):typeof define==='function'&&define.amd?define(['external'],f):(g=g||self,g.foo=f(g.x));}(this,(function(x){'use strict';x=x&&Object.prototype.hasOwnProperty.call(x,'default')?x['default']:x;var self=/*#__PURE__*/Object.freeze({__proto__:null,[Symbol.toStringTag]:'Module',get default(){return foo}});console.log(self);
 function foo () {
 	console.log( x );
 }
 // trailing comment
-return foo;})));
+return foo;})));

test/form/samples/namespace-tostringtag/_expected/amd.js

@@ -1,8 +1,8 @@
 define(['exports'], function (exports) { 'use strict';
 
 	var self = /*#__PURE__*/Object.freeze({
-		[Symbol.toStringTag]: 'Module',
 		__proto__: null,
+		[Symbol.toStringTag]: 'Module',
 		get p () { return p; }
 	});
 

test/form/samples/namespace-tostringtag/_expected/cjs.js

@@ -3,8 +3,8 @@
 Object.defineProperty(exports, '__esModule', { value: true });
 
 var self = /*#__PURE__*/Object.freeze({
-	[Symbol.toStringTag]: 'Module',
 	__proto__: null,
+	[Symbol.toStringTag]: 'Module',
 	get p () { return p; }
 });
 

test/form/samples/namespace-tostringtag/_expected/es.js

@@ -1,6 +1,6 @@
 var self = /*#__PURE__*/Object.freeze({
-	[Symbol.toStringTag]: 'Module',
 	__proto__: null,
+	[Symbol.toStringTag]: 'Module',
 	get p () { return p; }
 });
 

test/form/samples/namespace-tostringtag/_expected/iife.js

@@ -2,8 +2,8 @@ var iife = (function (exports) {
 	'use strict';
 
 	var self = /*#__PURE__*/Object.freeze({
-		[Symbol.toStringTag]: 'Module',
 		__proto__: null,
+		[Symbol.toStringTag]: 'Module',
 		get p () { return p; }
 	});
 

test/form/samples/namespace-tostringtag/_expected/system.js

@@ -4,8 +4,8 @@ System.register('iife', [], function (exports) {
 		execute: function () {
 
 			var self = /*#__PURE__*/Object.freeze({
-				[Symbol.toStringTag]: 'Module',
 				__proto__: null,
+				[Symbol.toStringTag]: 'Module',
 				get p () { return p; }
 			});
 

test/form/samples/namespace-tostringtag/_expected/umd.js

@@ -5,8 +5,8 @@
 }(this, (function (exports) { 'use strict';
 
 	var self = /*#__PURE__*/Object.freeze({
-		[Symbol.toStringTag]: 'Module',
 		__proto__: null,
+		[Symbol.toStringTag]: 'Module',
 		get p () { return p; }
 	});
 

test/form/samples/ns-external-star-reexport/_config.js

@@ -0,0 +1,24 @@
+module.exports = {
+	description: 'supports namespaces with external star reexports',
+	options: {
+		external: ['external1', 'external2'],
+		plugins: {
+			transform(code, id) {
+				if (id.endsWith('override.js')) {
+					return {
+						code,
+						syntheticNamedExports: true
+					};
+				}
+				return null;
+			}
+		},
+		output: {
+			globals: {
+				external1: 'external1',
+				external2: 'external2'
+			},
+			name: 'bundle'
+		}
+	}
+};

test/form/samples/ns-external-star-reexport/_expected/amd.js

@@ -0,0 +1,21 @@
+define(['exports', 'external1', 'external2'], function (exports, external1, external2) { 'use strict';
+
+	var reexportExternal = /*#__PURE__*/Object.freeze(/*#__PURE__*/Object.assign(/*#__PURE__*/Object.create(null), external1));
+
+	const extra = 'extra';
+
+	const override = 'override';
+	var reexportExternalsWithOverride = { synthetic: 'synthetic' };
+
+	var reexportExternalsWithOverride$1 = /*#__PURE__*/Object.freeze(/*#__PURE__*/Object.assign(/*#__PURE__*/Object.create(null), external1, external2, {
+		override: override,
+		'default': reexportExternalsWithOverride,
+		extra: extra
+	}, reexportExternalsWithOverride));
+
+	exports.external = reexportExternal;
+	exports.externalOverride = reexportExternalsWithOverride$1;
+
+	Object.defineProperty(exports, '__esModule', { value: true });
+
+});

test/form/samples/ns-external-star-reexport/_expected/cjs.js

@@ -0,0 +1,22 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+var external1 = require('external1');
+var external2 = require('external2');
+
+var reexportExternal = /*#__PURE__*/Object.freeze(/*#__PURE__*/Object.assign(/*#__PURE__*/Object.create(null), external1));
+
+const extra = 'extra';
+
+const override = 'override';
+var reexportExternalsWithOverride = { synthetic: 'synthetic' };
+
+var reexportExternalsWithOverride$1 = /*#__PURE__*/Object.freeze(/*#__PURE__*/Object.assign(/*#__PURE__*/Object.create(null), external1, external2, {
+	override: override,
+	'default': reexportExternalsWithOverride,
+	extra: extra
+}, reexportExternalsWithOverride));
+
+exports.external = reexportExternal;
+exports.externalOverride = reexportExternalsWithOverride$1;