fix #1890: regression due to lack of "__toESM()"

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+* Fix a regression with `export {} from` and CommonJS ([#1890](https://github.com/evanw/esbuild/issues/1890))
+
+    This release fixes a regression that was introduced by the change in 0.14.7 that avoids calling the `__toESM` wrapper for import statements that are converted to `require` calls and that don't use the `default` or `__esModule` export names. The previous change was correct for the `import {} from` syntax but not for the `export {} from` syntax, which meant that in certain cases with re-exported values, the value of the `default` import could be different than expected. This release fixes the regression.
+
 * Warn about using `module` or `exports` in ESM code ([#1887](https://github.com/evanw/esbuild/issues/1887))
 
     CommonJS export variables cannot be referenced in ESM code. If you do this, they are treated as global variables instead. This release includes a warning for people that try to use both CommonJS and ES module export styles in the same file. Here's an example:

internal/bundler/snapshots/snapshots_default.txt

@@ -2372,10 +2372,10 @@ __export(entry_exports, {
   bar: () => import_bar.default,
   foo: () => import_foo.default
 });
-var import_foo = require("foo");
+var import_foo = __toESM(require("foo"));
 
 // bar.js
-var import_bar = require("bar");
+var import_bar = __toESM(require("bar"));
 module.exports = __toCommonJS(entry_exports);
 
 ================================================================================
@@ -2418,8 +2418,8 @@ __export(entry_exports, {
   bar: () => import_bar.default,
   foo: () => import_foo.default
 });
-var import_foo = require("./foo");
-var import_bar = require("./bar");
+var import_foo = __toESM(require("./foo"));
+var import_bar = __toESM(require("./bar"));
 module.exports = __toCommonJS(entry_exports);
 
 ================================================================================

internal/bundler/snapshots/snapshots_importstar.txt

@@ -869,7 +869,7 @@ var entry_exports = {};
 __export(entry_exports, {
   out: () => out
 });
-var out = require("foo");
+var out = __toESM(require("foo"));
 module.exports = __toCommonJS(entry_exports);
 
 ================================================================================
@@ -888,7 +888,7 @@ var entry_exports = {};
 __export(entry_exports, {
   out: () => out
 });
-var out = require("foo");
+var out = __toESM(require("foo"));
 module.exports = __toCommonJS(entry_exports);
 
 ================================================================================
@@ -909,7 +909,7 @@ var mod = (() => {
   __export(entry_exports, {
     out: () => out
   });
-  var out = __require("foo");
+  var out = __toESM(__require("foo"));
   return __toCommonJS(entry_exports);
 })();
 
@@ -921,7 +921,7 @@ var mod = (() => {
   __export(entry_exports, {
     out: () => out
   });
-  var out = require("foo");
+  var out = __toESM(require("foo"));
   return __toCommonJS(entry_exports);
 })();
 

internal/js_parser/js_parser.go

@@ -13849,6 +13849,7 @@ func (p *parser) scanForImportsAndExports(stmts []js_ast.Stmt) (result importsEx
 			}
 
 		case *js_ast.SExportStar:
+			record := &p.importRecords[s.ImportRecordIndex]
 			p.importRecordsForCurrentPart = append(p.importRecordsForCurrentPart, s.ImportRecordIndex)
 
 			if s.Alias != nil {
@@ -13861,12 +13862,15 @@ func (p *parser) scanForImportsAndExports(stmts []js_ast.Stmt) (result importsEx
 					IsExported:        true,
 				}
 				p.recordExport(s.Alias.Loc, s.Alias.OriginalName, s.NamespaceRef)
+
+				record.Flags |= ast.ContainsImportStar
 			} else {
 				// "export * from 'path'"
 				p.exportStarImportRecords = append(p.exportStarImportRecords, s.ImportRecordIndex)
 			}
 
 		case *js_ast.SExportFrom:
+			record := &p.importRecords[s.ImportRecordIndex]
 			p.importRecordsForCurrentPart = append(p.importRecordsForCurrentPart, s.ImportRecordIndex)
 
 			for _, item := range s.Items {
@@ -13881,6 +13885,12 @@ func (p *parser) scanForImportsAndExports(stmts []js_ast.Stmt) (result importsEx
 					IsExported:        true,
 				}
 				p.recordExport(item.Name.Loc, item.Alias, item.Name.Ref)
+
+				if item.OriginalName == "default" {
+					record.Flags |= ast.ContainsDefaultAlias
+				} else if item.OriginalName == "__esModule" {
+					record.Flags |= ast.ContainsESModuleAlias
+				}
 			}
 		}
 

scripts/end-to-end-tests.js

@@ -1395,6 +1395,39 @@
       'in.mjs': `import * as ns from './foo'; if (!ns.default || ns.default.foo !== 123) throw 'fail'`,
       'foo.js': `exports.__esModule = true; exports.foo = 123`,
     }),
+
+    // Make sure "import {} from; export {}" behaves like "export {} from"
+    // https://github.com/evanw/esbuild/issues/1890
+    test(['node.ts', 'foo.ts', '--outdir=.', '--format=cjs'], {
+      'node.ts': `import * as foo from './foo.js'; if (foo.bar !== 123) throw 'fail'`,
+      'foo.ts': `import bar from './lib.js'; export { bar }`,
+      'lib.js': `module.exports = 123`,
+    }),
+    test(['node.ts', 'foo.ts', '--outdir=.', '--format=cjs'], {
+      'node.ts': `import * as foo from './foo.js'; if (foo.bar !== 123) throw 'fail'`,
+      'foo.ts': `import { default as bar } from './lib.js'; export { bar }`,
+      'lib.js': `module.exports = 123`,
+    }),
+    test(['node.ts', 'foo.ts', '--outdir=.', '--format=cjs'], {
+      'node.ts': `import * as foo from './foo.js'; if (foo.bar !== 123) throw 'fail'`,
+      'foo.ts': `export { default as bar } from './lib.js'`,
+      'lib.js': `module.exports = 123`,
+    }),
+    test(['node.ts', 'foo.ts', '--outdir=.', '--format=cjs'], {
+      'node.ts': `import { foo } from './foo.js'; if (foo.default !== 123) throw 'fail'`,
+      'foo.ts': `import * as foo from './lib.js'; export { foo }`,
+      'lib.js': `module.exports = 123`,
+    }),
+    test(['node.ts', 'foo.ts', '--outdir=.', '--format=cjs'], {
+      'node.ts': `import { foo } from './foo.js'; if (foo.default !== 123) throw 'fail'`,
+      'foo.ts': `export * as foo from './lib.js'`,
+      'lib.js': `module.exports = 123`,
+    }),
+    test(['node.ts', 'foo.ts', '--outdir=.', '--format=cjs'], {
+      'node.ts': `import * as foo from './foo.js'; if (foo.default !== void 0) throw 'fail'`,
+      'foo.ts': `export * from './lib.js'`,
+      'lib.js': `module.exports = 123`,
+    }),
   )
 
   // Test external CommonJS export