From 7715955f89d4e5c7a26b18f4e15a19e7ae330e6d Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrewbranch@users.noreply.github.com>
Date: Fri, 6 Jun 2025 15:08:04 -0700
Subject: [PATCH] Fix helpers emit for .cjs files in ESM module mode (#61814)

---
 src/compiler/factory/utilities.ts             |  7 +++---
 .../ctsFileInEsnextHelpers.errors.txt         |  9 +++++++
 .../reference/ctsFileInEsnextHelpers.js       | 24 +++++++++++++++++++
 .../cases/compiler/ctsFileInEsnextHelpers.ts  |  8 +++++++
 4 files changed, 45 insertions(+), 3 deletions(-)
 create mode 100644 tests/baselines/reference/ctsFileInEsnextHelpers.errors.txt
 create mode 100644 tests/baselines/reference/ctsFileInEsnextHelpers.js
 create mode 100644 tests/cases/compiler/ctsFileInEsnextHelpers.ts

diff --git a/src/compiler/factory/utilities.ts b/src/compiler/factory/utilities.ts
index f3ed23b5824..d58b118a8e3 100644
--- a/src/compiler/factory/utilities.ts
+++ b/src/compiler/factory/utilities.ts
@@ -700,9 +700,10 @@ export function createExternalHelpersImportDeclarationIfNeeded(nodeFactory: Node
         const impliedModuleKind = getImpliedNodeFormatForEmitWorker(sourceFile, compilerOptions);
         const helpers = getImportedHelpers(sourceFile);
         if (
-            (moduleKind >= ModuleKind.ES2015 && moduleKind <= ModuleKind.ESNext) ||
-            impliedModuleKind === ModuleKind.ESNext ||
-            impliedModuleKind === undefined && moduleKind === ModuleKind.Preserve
+            impliedModuleKind !== ModuleKind.CommonJS &&
+            ((moduleKind >= ModuleKind.ES2015 && moduleKind <= ModuleKind.ESNext) ||
+                impliedModuleKind === ModuleKind.ESNext ||
+                impliedModuleKind === undefined && moduleKind === ModuleKind.Preserve)
         ) {
             // When we emit as an ES module, generate an `import` declaration that uses named imports for helpers.
             // If we cannot determine the implied module kind under `module: preserve` we assume ESM.
diff --git a/tests/baselines/reference/ctsFileInEsnextHelpers.errors.txt b/tests/baselines/reference/ctsFileInEsnextHelpers.errors.txt
new file mode 100644
index 00000000000..b43c66af419
--- /dev/null
+++ b/tests/baselines/reference/ctsFileInEsnextHelpers.errors.txt
@@ -0,0 +1,9 @@
+notmodule.cts(1,23): error TS2354: This syntax requires an imported helper but module 'tslib' cannot be found.
+
+
+==== notmodule.cts (1 errors) ====
+    export async function foo() {
+                          ~~~
+!!! error TS2354: This syntax requires an imported helper but module 'tslib' cannot be found.
+      await 0;
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/ctsFileInEsnextHelpers.js b/tests/baselines/reference/ctsFileInEsnextHelpers.js
new file mode 100644
index 00000000000..e08d213dfff
--- /dev/null
+++ b/tests/baselines/reference/ctsFileInEsnextHelpers.js
@@ -0,0 +1,24 @@
+//// [tests/cases/compiler/ctsFileInEsnextHelpers.ts] ////
+
+//// [notmodule.cts]
+export async function foo() {
+  await 0;
+}
+
+//// [notmodule.cjs]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.foo = foo;
+var tslib_1 = require("tslib");
+function foo() {
+    return tslib_1.__awaiter(this, void 0, void 0, function () {
+        return tslib_1.__generator(this, function (_a) {
+            switch (_a.label) {
+                case 0: return [4 /*yield*/, 0];
+                case 1:
+                    _a.sent();
+                    return [2 /*return*/];
+            }
+        });
+    });
+}
diff --git a/tests/cases/compiler/ctsFileInEsnextHelpers.ts b/tests/cases/compiler/ctsFileInEsnextHelpers.ts
new file mode 100644
index 00000000000..6708f6266b5
--- /dev/null
+++ b/tests/cases/compiler/ctsFileInEsnextHelpers.ts
@@ -0,0 +1,8 @@
+// @module: es2015
+// @importHelpers: true
+// @noTypesAndSymbols: true
+
+// @Filename: notmodule.cts
+export async function foo() {
+  await 0;
+}
\ No newline at end of file