From c175fefcfd7ee741803d197167cebae7c9eb864d Mon Sep 17 00:00:00 2001
From: Matthew Hershberger <matthewh@multipart.net>
Date: Wed, 19 Jun 2024 12:23:25 -0400
Subject: [PATCH] fix(node): #1180 - Adjust tsconfig compiler options

Accidentally applied `es6` when compilerOptions.module was not defined.
---
 CHANGELOG.md                              |  2 +-
 source/runner/runners/utils/transpiler.ts | 12 ++++++++----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6fbb9acd2..c01fcac34 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,7 +15,7 @@
 ## Main
 
 <!-- Your comment below this -->
-
+- [#1180] Set module properly when tsconfig does not contain compilerOptions.module [@matthewh]
 <!-- Your comment above this -->
 
 ## 12.3.2
diff --git a/source/runner/runners/utils/transpiler.ts b/source/runner/runners/utils/transpiler.ts
index 081031b0e..15ca593fd 100644
--- a/source/runner/runners/utils/transpiler.ts
+++ b/source/runner/runners/utils/transpiler.ts
@@ -149,10 +149,14 @@ const sanitizeTSConfig = (config: any, esm: boolean = false) => {
   //
   // @see https://github.com/apollographql/react-apollo/pull/1402#issuecomment-351810274
   //
-  if (!esm && safeConfig.compilerOptions.module) {
-    safeConfig.compilerOptions.module = "commonjs"
-  } else {
-    safeConfig.compilerOptions.module = "es6"
+  if (safeConfig.compilerOptions.module) {
+    if (!esm) {
+      // .ts files should fall back to commonjs
+      safeConfig.compilerOptions.module = "commonjs"
+    } else {
+      // .mts files must use `import`/`export` syntax
+      safeConfig.compilerOptions.module = "es6"
+    }
   }
 
   return safeConfig