Handle specifier as default with enableLegacyBabel5ModuleInterop (#804)

alangpierce · Jul 11, 2023 · 631f64c · 631f64c
1 parent 6854479
commit 631f64c
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Showing 2 changed files with 57 additions and 30 deletions.
diff --git a/src/transformers/CJSImportTransformer.ts b/src/transformers/CJSImportTransformer.ts
@@ -292,35 +292,9 @@ export default class CJSImportTransformer extends Transformer {
       }
       this.processExportDefault();
       return true;
-    }
-    this.hadNamedExport = true;
-    if (
-      this.tokens.matches2(tt._export, tt._var) ||
-      this.tokens.matches2(tt._export, tt._let) ||
-      this.tokens.matches2(tt._export, tt._const)
-    ) {
-      this.processExportVar();
-      return true;
-    } else if (
-      this.tokens.matches2(tt._export, tt._function) ||
-      // export async function
-      this.tokens.matches3(tt._export, tt.name, tt._function)
-    ) {
-      this.processExportFunction();
-      return true;
-    } else if (
-      this.tokens.matches2(tt._export, tt._class) ||
-      this.tokens.matches3(tt._export, tt._abstract, tt._class) ||
-      this.tokens.matches2(tt._export, tt.at)
-    ) {
-      this.processExportClass();
-      return true;
     } else if (this.tokens.matches2(tt._export, tt.braceL)) {
       this.processExportBindings();
       return true;
-    } else if (this.tokens.matches2(tt._export, tt.star)) {
-      this.processExportStar();
-      return true;
     } else if (
       this.tokens.matches2(tt._export, tt.name) &&
       this.tokens.matchesContextualAtIndex(this.tokens.currentIndex() + 1, ContextualKeyword._type)
@@ -357,6 +331,32 @@ export default class CJSImportTransformer extends Transformer {
         removeMaybeImportAttributes(this.tokens);
       }
       return true;
+    }
+    this.hadNamedExport = true;
+    if (
+      this.tokens.matches2(tt._export, tt._var) ||
+      this.tokens.matches2(tt._export, tt._let) ||
+      this.tokens.matches2(tt._export, tt._const)
+    ) {
+      this.processExportVar();
+      return true;
+    } else if (
+      this.tokens.matches2(tt._export, tt._function) ||
+      // export async function
+      this.tokens.matches3(tt._export, tt.name, tt._function)
+    ) {
+      this.processExportFunction();
+      return true;
+    } else if (
+      this.tokens.matches2(tt._export, tt._class) ||
+      this.tokens.matches3(tt._export, tt._abstract, tt._class) ||
+      this.tokens.matches2(tt._export, tt.at)
+    ) {
+      this.processExportClass();
+      return true;
+    } else if (this.tokens.matches2(tt._export, tt.star)) {
+      this.processExportStar();
+      return true;
     } else {
       throw new Error("Unrecognized export syntax.");
     }
@@ -798,14 +798,23 @@ export default class CJSImportTransformer extends Transformer {
       }
 
       const specifierInfo = getImportExportSpecifierInfo(this.tokens);
+
       while (this.tokens.currentIndex() < specifierInfo.endIndex) {
         this.tokens.removeToken();
       }
-      if (!specifierInfo.isType && !this.shouldElideExportedIdentifier(specifierInfo.leftName)) {
-        const localName = specifierInfo.leftName;
+
+      if (!specifierInfo.isType) {
         const exportedName = specifierInfo.rightName;
-        const newLocalName = this.importProcessor.getIdentifierReplacement(localName);
-        exportStatements.push(`exports.${exportedName} = ${newLocalName || localName};`);
+        if (exportedName === "default") {
+          this.hadDefaultExport = true;
+        } else {
+          this.hadNamedExport = true;
+        }
+        if (!this.shouldElideExportedIdentifier(specifierInfo.leftName)) {
+          const localName = specifierInfo.leftName;
+          const newLocalName = this.importProcessor.getIdentifierReplacement(localName);
+          exportStatements.push(`exports.${exportedName} = ${newLocalName || localName};`);
+        }
       }
 
       if (this.tokens.matches1(tt.braceR)) {

diff --git a/test/imports-test.ts b/test/imports-test.ts
@@ -768,6 +768,24 @@ module.exports = exports.default;
 `,
       {transforms: ["imports"], enableLegacyBabel5ModuleInterop: true},
     );
+
+    assertResult(
+      `
+      export { x as default } from './foo'
+      export {}
+      export type A = string
+      export { type A as B }
+    `,
+      `"use strict";${ESMODULE_PREFIX}${CREATE_NAMED_EXPORT_FROM_PREFIX}
+      var _foo = require('./foo'); _createNamedExportFrom(_foo, 'default', 'x');
+      
+      
+      
+    
+module.exports = exports.default;
+`,
+      {transforms: ["imports", "typescript"], enableLegacyBabel5ModuleInterop: true},
+    );
   });
 
   it("does not add module exports suffix when there is a named export", () => {