Always respect synthetic namespaces in namespace reexports (#3894)

* Always respect synthetic namespaces in namespace reexports * Favour explicit named exports over synthetic ones for multiple namespace exports
rollup · Jan 19, 2021 · 0ed8722 · 0ed8722
1 parent 5d33573
commit 0ed8722
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Showing 6 changed files with 50 additions and 17 deletions.
diff --git a/src/Module.ts b/src/Module.ts
@@ -527,6 +527,7 @@ export default class Module {
 		}
 
 		if (name !== 'default') {
+			let foundSyntheticDeclaration: SyntheticNamedExportVariable | null = null;
 			for (const module of this.exportAllModules) {
 				const declaration = getVariableForExportNameRecursive(
 					module,
@@ -535,28 +536,38 @@ export default class Module {
 					searchedNamesAndModules
 				);
 
-				if (declaration) return declaration;
+				if (declaration) {
+					if (!(declaration instanceof SyntheticNamedExportVariable)) {
+						return declaration;
+					}
+					if (!foundSyntheticDeclaration) {
+						foundSyntheticDeclaration = declaration;
+					}
+				}
+			}
+			if (foundSyntheticDeclaration) {
+				return foundSyntheticDeclaration;
 			}
 		}
 
-		// we don't want to create shims when we are just
-		// probing export * modules for exports
-		if (!isExportAllSearch) {
-			if (this.info.syntheticNamedExports) {
-				let syntheticExport = this.syntheticExports.get(name);
-				if (!syntheticExport) {
-					const syntheticNamespace = this.getSyntheticNamespace();
-					syntheticExport = new SyntheticNamedExportVariable(
-						this.astContext,
-						name,
-						syntheticNamespace
-					);
-					this.syntheticExports.set(name, syntheticExport);
-					return syntheticExport;
-				}
+		if (this.info.syntheticNamedExports) {
+			let syntheticExport = this.syntheticExports.get(name);
+			if (!syntheticExport) {
+				const syntheticNamespace = this.getSyntheticNamespace();
+				syntheticExport = new SyntheticNamedExportVariable(
+					this.astContext,
+					name,
+					syntheticNamespace
+				);
+				this.syntheticExports.set(name, syntheticExport);
 				return syntheticExport;
 			}
+			return syntheticExport;
+		}
 
+		// we don't want to create shims when we are just
+		// probing export * modules for exports
+		if (!isExportAllSearch) {
 			if (this.options.shimMissingExports) {
 				this.shimMissingExport(name);
 				return this.exportShimVariable;
@@ -623,7 +634,7 @@ export default class Module {
 		this.addModulesToImportDescriptions(this.importDescriptions);
 		this.addModulesToImportDescriptions(this.reexportDescriptions);
 		for (const name in this.exports) {
-			if (name !== 'default') {
+			if (name !== 'default' && name !== this.info.syntheticNamedExports) {
 				this.exportsAll[name] = this.id;
 			}
 		}

diff --git a/test/function/samples/reexport-from-synthetic/_config.js b/test/function/samples/reexport-from-synthetic/_config.js
@@ -0,0 +1,12 @@
+module.exports = {
+	description: 'handles reexporting a synthetic namespace from a non-synthetic module',
+	options: {
+		plugins: [
+			{
+				transform() {
+					return { syntheticNamedExports: '__synth' };
+				}
+			}
+		]
+	}
+};
diff --git a/test/function/samples/reexport-from-synthetic/main.js b/test/function/samples/reexport-from-synthetic/main.js
@@ -0,0 +1,4 @@
+import { synth, explicit1, explicit2 } from './reexport.js';
+assert.strictEqual(synth, 1);
+assert.strictEqual(explicit1, 2);
+assert.strictEqual(explicit2, 4);
diff --git a/test/function/samples/reexport-from-synthetic/reexport.js b/test/function/samples/reexport-from-synthetic/reexport.js
@@ -0,0 +1,2 @@
+export * from './synthetic1.js';
+export * from './synthetic2.js';
diff --git a/test/function/samples/reexport-from-synthetic/synthetic1.js b/test/function/samples/reexport-from-synthetic/synthetic1.js
@@ -0,0 +1,2 @@
+export const __synth = { synth: 1 };
+export const explicit1 = 2;
diff --git a/test/function/samples/reexport-from-synthetic/synthetic2.js b/test/function/samples/reexport-from-synthetic/synthetic2.js
@@ -0,0 +1,2 @@
+export const __synth = { synth: 3 };
+export const explicit2 = 4;