From 1adb3b73a09e9f29978eca509cd498f850f9b02c Mon Sep 17 00:00:00 2001
From: zodern <zodern@users.noreply.github.com>
Date: Wed, 25 May 2022 12:36:16 -0500
Subject: [PATCH] Allow export.__esModule to be overwritten Avoids an error if
 the file was already compiled by babel, and babel adds the line
 `exports.__esModule = true`. Fixes
 https://github.com/meteor/meteor/issues/12035

---
 lib/runtime/utils.js                  |  2 +-
 test/misc-tests.js                    |  6 ++++++
 test/misc/__esModule-export-after.js  |  3 +++
 test/misc/__esModule-export-before.js | 10 ++++++++++
 4 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 test/misc/__esModule-export-after.js
 create mode 100644 test/misc/__esModule-export-before.js

diff --git a/lib/runtime/utils.js b/lib/runtime/utils.js
index df8db147..aebddb99 100644
--- a/lib/runtime/utils.js
+++ b/lib/runtime/utils.js
@@ -70,7 +70,7 @@ function setESModule(exported) {
         configurable: true,
         enumerable: false,
         value: true,
-        writable: false
+        writable: true
       });
     }
   }
diff --git a/test/misc-tests.js b/test/misc-tests.js
index 97b5ff29..c7f8a59b 100644
--- a/test/misc-tests.js
+++ b/test/misc-tests.js
@@ -92,3 +92,9 @@ describe("object-like module.exports", () => {
     assert.strictEqual(typeof forEach, "function");
   });
 });
+
+describe("setEsModule", () => {
+  it("should not error if __esModule is set before or after setEsModule is called", () => {
+    import './misc/__esModule-export-after';
+  });
+});
diff --git a/test/misc/__esModule-export-after.js b/test/misc/__esModule-export-after.js
new file mode 100644
index 00000000..e1962a57
--- /dev/null
+++ b/test/misc/__esModule-export-after.js
@@ -0,0 +1,3 @@
+import './__esModule-export-before.js';
+
+exports.__esModule = true
diff --git a/test/misc/__esModule-export-before.js b/test/misc/__esModule-export-before.js
new file mode 100644
index 00000000..0816829e
--- /dev/null
+++ b/test/misc/__esModule-export-before.js
@@ -0,0 +1,10 @@
+Object.defineProperty(module.exports, '__esModule', {
+  configurable: false,
+  enumerable: false,
+  value: true,
+  writable: false
+});
+
+module.export({
+  a: () => 5
+});