Prefer locally defined exports and reexports over external namespaces

src/ExternalModule.ts

@@ -112,7 +112,7 @@ export default class ExternalModule {
 
 		const importersSet = new Set<string>();
 		for (const name of unused) {
-			const {importers, dynamicImporters} = this.declarations[name].module;
+			const { importers, dynamicImporters } = this.declarations[name].module;
 
 			if (Array.isArray(importers)) importers.forEach(v => importersSet.add(v));
 			if (Array.isArray(dynamicImporters)) dynamicImporters.forEach(v => importersSet.add(v));

src/Module.ts

@@ -45,6 +45,7 @@ import {
 	RollupWarning,
 	TransformModuleJSON
 } from './rollup/types';
+import { EMPTY_OBJECT } from './utils/blank';
 import {
 	augmentCodeLocation,
 	errCircularReexport,
@@ -129,8 +130,11 @@ function findSourceMappingURLComments(ast: acorn.Node, code: string): [number, n
 
 		let sourcemappingUrlMatch;
 		const interStatmentCode = code.slice(start, end);
-		while (sourcemappingUrlMatch = SOURCEMAPPING_URL_COMMENT_RE.exec(interStatmentCode)) {
-			ret.push([start + sourcemappingUrlMatch.index, start + SOURCEMAPPING_URL_COMMENT_RE.lastIndex]);
+		while ((sourcemappingUrlMatch = SOURCEMAPPING_URL_COMMENT_RE.exec(interStatmentCode))) {
+			ret.push([
+				start + sourcemappingUrlMatch.index,
+				start + SOURCEMAPPING_URL_COMMENT_RE.lastIndex
+			]);
 		}
 	};
 
@@ -149,7 +153,8 @@ function getVariableForExportNameRecursive(
 	name: string,
 	importerForSideEffects: Module | undefined,
 	isExportAllSearch: boolean,
-	searchedNamesAndModules = new Map<string, Set<Module | ExternalModule>>()
+	searchedNamesAndModules = new Map<string, Set<Module | ExternalModule>>(),
+	skipExternalNamespaceReexports: boolean | undefined
 ): Variable | null {
 	const searchedModules = searchedNamesAndModules.get(name);
 	if (searchedModules) {
@@ -160,12 +165,12 @@ function getVariableForExportNameRecursive(
 	} else {
 		searchedNamesAndModules.set(name, new Set([target]));
 	}
-	return target.getVariableForExportName(
-		name,
+	return target.getVariableForExportName(name, {
 		importerForSideEffects,
 		isExportAllSearch,
-		searchedNamesAndModules
-	);
+		searchedNamesAndModules,
+		skipExternalNamespaceReexports
+	});
 }
 
 function getAndExtendSideEffectModules(variable: Variable, module: Module): Set<Module> {
@@ -482,9 +487,17 @@ export default class Module {
 
 	getVariableForExportName(
 		name: string,
-		importerForSideEffects?: Module,
-		isExportAllSearch?: boolean,
-		searchedNamesAndModules?: Map<string, Set<Module | ExternalModule>>
+		{
+			importerForSideEffects,
+			isExportAllSearch,
+			searchedNamesAndModules,
+			skipExternalNamespaceReexports
+		}: {
+			importerForSideEffects?: Module;
+			isExportAllSearch?: boolean;
+			searchedNamesAndModules?: Map<string, Set<Module | ExternalModule>>;
+			skipExternalNamespaceReexports?: boolean;
+		} = EMPTY_OBJECT
 	): Variable | null {
 		if (name[0] === '*') {
 			if (name.length === 1) {
@@ -505,7 +518,8 @@ export default class Module {
 				reexportDeclaration.localName,
 				importerForSideEffects,
 				false,
-				searchedNamesAndModules
+				searchedNamesAndModules,
+				false
 			);
 
 			if (!variable) {
@@ -540,21 +554,27 @@ export default class Module {
 
 		if (name !== 'default') {
 			let foundSyntheticDeclaration: SyntheticNamedExportVariable | null = null;
-			for (const module of this.exportAllModules) {
-				const declaration = getVariableForExportNameRecursive(
-					module,
-					name,
-					importerForSideEffects,
-					true,
-					searchedNamesAndModules
-				);
-
-				if (declaration) {
-					if (!(declaration instanceof SyntheticNamedExportVariable)) {
-						return declaration;
-					}
-					if (!foundSyntheticDeclaration) {
-						foundSyntheticDeclaration = declaration;
+			const skipExternalNamespaceValues = new Set([true, skipExternalNamespaceReexports]);
+			for (const skipExternalNamespaces of skipExternalNamespaceValues) {
+				for (const module of this.exportAllModules) {
+					if (module instanceof Module || !skipExternalNamespaces) {
+						const declaration = getVariableForExportNameRecursive(
+							module,
+							name,
+							importerForSideEffects,
+							true,
+							searchedNamesAndModules,
+							skipExternalNamespaces
+						);
+
+						if (declaration) {
+							if (!(declaration instanceof SyntheticNamedExportVariable)) {
+								return declaration;
+							}
+							if (!foundSyntheticDeclaration) {
+								foundSyntheticDeclaration = declaration;
+							}
+						}
 					}
 				}
 			}
@@ -798,10 +818,9 @@ export default class Module {
 				return otherModule.namespace;
 			}
 
-			const declaration = otherModule.getVariableForExportName(
-				importDeclaration.name,
-				importerForSideEffects || this
-			);
+			const declaration = otherModule.getVariableForExportName(importDeclaration.name, {
+				importerForSideEffects: importerForSideEffects || this
+			});
 
 			if (!declaration) {
 				return this.error(
@@ -837,7 +856,6 @@ export default class Module {
 		}
 	}
 
-
 	updateOptions({
 		meta,
 		moduleSideEffects,

test/form/samples/namespace-reexport-name/_config.js

@@ -0,0 +1,4 @@
+module.exports = {
+	description: 'uses correct names when reexporting from namespace reexports (#4049)',
+	options: { external: 'external', output: { name: 'bundle' } }
+};

test/form/samples/namespace-reexport-name/_expected/amd.js

@@ -0,0 +1,29 @@
+define(['exports', 'external'], function (exports, external) { 'use strict';
+
+	const renamedIndirectOverride = external.indirectOverride;
+
+	Object.defineProperty(exports, 'noOverride', {
+		enumerable: true,
+		get: function () {
+			return external.noOverride;
+		}
+	});
+	Object.defineProperty(exports, 'renamedDirectOverride', {
+		enumerable: true,
+		get: function () {
+			return external.directOverride;
+		}
+	});
+	exports.renamedIndirectOverride = renamedIndirectOverride;
+	Object.keys(external).forEach(function (k) {
+		if (k !== 'default' && !exports.hasOwnProperty(k)) Object.defineProperty(exports, k, {
+			enumerable: true,
+			get: function () {
+				return external[k];
+			}
+		});
+	});
+
+	Object.defineProperty(exports, '__esModule', { value: true });
+
+});

test/form/samples/namespace-reexport-name/_expected/cjs.js

@@ -0,0 +1,29 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+var external = require('external');
+
+const renamedIndirectOverride = external.indirectOverride;
+
+Object.defineProperty(exports, 'noOverride', {
+	enumerable: true,
+	get: function () {
+		return external.noOverride;
+	}
+});
+Object.defineProperty(exports, 'renamedDirectOverride', {
+	enumerable: true,
+	get: function () {
+		return external.directOverride;
+	}
+});
+exports.renamedIndirectOverride = renamedIndirectOverride;
+Object.keys(external).forEach(function (k) {
+	if (k !== 'default' && !exports.hasOwnProperty(k)) Object.defineProperty(exports, k, {
+		enumerable: true,
+		get: function () {
+			return external[k];
+		}
+	});
+});

test/form/samples/namespace-reexport-name/_expected/es.js

@@ -0,0 +1,7 @@
+import { indirectOverride } from 'external';
+export * from 'external';
+export { noOverride, directOverride as renamedDirectOverride } from 'external';
+
+const renamedIndirectOverride = indirectOverride;
+
+export { renamedIndirectOverride };

test/form/samples/namespace-reexport-name/_expected/iife.js

@@ -0,0 +1,32 @@
+var bundle = (function (exports, external) {
+	'use strict';
+
+	const renamedIndirectOverride = external.indirectOverride;
+
+	Object.defineProperty(exports, 'noOverride', {
+		enumerable: true,
+		get: function () {
+			return external.noOverride;
+		}
+	});
+	Object.defineProperty(exports, 'renamedDirectOverride', {
+		enumerable: true,
+		get: function () {
+			return external.directOverride;
+		}
+	});
+	exports.renamedIndirectOverride = renamedIndirectOverride;
+	Object.keys(external).forEach(function (k) {
+		if (k !== 'default' && !exports.hasOwnProperty(k)) Object.defineProperty(exports, k, {
+			enumerable: true,
+			get: function () {
+				return external[k];
+			}
+		});
+	});
+
+	Object.defineProperty(exports, '__esModule', { value: true });
+
+	return exports;
+
+}({}, external));

test/form/samples/namespace-reexport-name/_expected/system.js

@@ -0,0 +1,22 @@
+System.register('bundle', ['external'], function (exports) {
+	'use strict';
+	var _starExcludes = { renamedIndirectOverride: 1, default: 1, noOverride: 1, renamedDirectOverride: 1 };
+	var indirectOverride;
+	return {
+		setters: [function (module) {
+			indirectOverride = module.indirectOverride;
+			var _setter = {};
+			for (var _$p in module) {
+				if (!_starExcludes[_$p]) _setter[_$p] = module[_$p];
+			}
+			_setter.noOverride = module.noOverride;
+			_setter.renamedDirectOverride = module.directOverride;
+			exports(_setter);
+		}],
+		execute: function () {
+
+			const renamedIndirectOverride = exports('renamedIndirectOverride', indirectOverride);
+
+		}
+	};
+});

test/form/samples/namespace-reexport-name/_expected/umd.js

@@ -0,0 +1,33 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('external')) :
+	typeof define === 'function' && define.amd ? define(['exports', 'external'], factory) :
+	(global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.bundle = {}, global.external));
+}(this, (function (exports, external) { 'use strict';
+
+	const renamedIndirectOverride = external.indirectOverride;
+
+	Object.defineProperty(exports, 'noOverride', {
+		enumerable: true,
+		get: function () {
+			return external.noOverride;
+		}
+	});
+	Object.defineProperty(exports, 'renamedDirectOverride', {
+		enumerable: true,
+		get: function () {
+			return external.directOverride;
+		}
+	});
+	exports.renamedIndirectOverride = renamedIndirectOverride;
+	Object.keys(external).forEach(function (k) {
+		if (k !== 'default' && !exports.hasOwnProperty(k)) Object.defineProperty(exports, k, {
+			enumerable: true,
+			get: function () {
+				return external[k];
+			}
+		});
+	});
+
+	Object.defineProperty(exports, '__esModule', { value: true });
+
+})));

test/form/samples/namespace-reexport-name/external-reexport.js

@@ -0,0 +1,2 @@
+export * from 'external';
+export { noOverride } from 'external';

test/form/samples/namespace-reexport-name/main.js

@@ -0,0 +1,2 @@
+export * from './external-reexport';
+export * from './overrides';

test/form/samples/namespace-reexport-name/overrides.js

@@ -0,0 +1,5 @@
+import { indirectOverride, ignoredOverride } from './external-reexport';
+export { directOverride as renamedDirectOverride } from './external-reexport';
+
+export const renamedIndirectOverride = indirectOverride;
+export const noOverride = ignoredOverride;