From 60f6ea42db67e3df5249040c8e367e8cecb06b5a Mon Sep 17 00:00:00 2001
From: usimd <11619247+usimd@users.noreply.github.com>
Date: Sun, 7 Jun 2026 21:28:20 +0200
Subject: [PATCH] chore: migrate to ESM

Switch from CommonJS to ES modules to unblock major dependency upgrades.
@actions/core v3, @actions/exec v3, and @actions/tool-cache v4 all dropped
CJS support (exports field is import-only), which caused ncc to fail.

- Add "type": "module" to package.json
- Update tsconfig: module/moduleResolution -> nodenext, target -> ES2022
- Replace require.main === module guard with import.meta.url equivalent
- ncc now compiles to ESM (confirmed locally)
---
 package.json         |  1 +
 src/main.ts          |  3 ++-
 tsconfig.eslint.json |  3 ++-
 tsconfig.json        | 10 ++++++----
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/package.json b/package.json
index b839fa3..7f12285 100644
--- a/package.json
+++ b/package.json
@@ -2,6 +2,7 @@
   "name": "setup-xc-action",
   "version": "1.0.1",
   "description": "GitHub Action to setup Microchip XC compilers",
+  "type": "module",
   "main": "dist/index.js",
   "scripts": {
     "build": "ncc build src/main.ts -m --no-source-map-register --license licenses.txt",
diff --git a/src/main.ts b/src/main.ts
index 079cdb0..6d1b020 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -289,6 +289,7 @@ export async function run(): Promise<void> {
 }
 
 // Only run if this file is being executed directly (not imported for testing)
-if (require.main === module) {
+const isMain = import.meta.url === new URL(process.argv[1], 'file:').href
+if (isMain) {
   run()
 }
diff --git a/tsconfig.eslint.json b/tsconfig.eslint.json
index 616cdbf..ff74c87 100644
--- a/tsconfig.eslint.json
+++ b/tsconfig.eslint.json
@@ -3,7 +3,8 @@
   "include": ["src/**/*", "__tests__/**/*"],
   "exclude": ["node_modules"],
   "compilerOptions": {
-    "types": ["node", "vitest/globals"]
+    "types": ["node", "vitest/globals"],
+    "rootDir": "."
   }
 }
 
diff --git a/tsconfig.json b/tsconfig.json
index ac56c14..c8aad91 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,8 +1,9 @@
 {
   "compilerOptions": {
-    "target": "ES2021",
-    "module": "commonjs",
-    "lib": ["ES2021"],
+    "target": "ES2022",
+    "module": "nodenext",
+    "moduleResolution": "nodenext",
+    "lib": ["ES2022"],
     "outDir": "./lib",
     "rootDir": "./src",
     "strict": true,
@@ -13,7 +14,8 @@
     "resolveJsonModule": true,
     "declaration": true,
     "declarationMap": true,
-    "sourceMap": true
+    "sourceMap": true,
+    "verbatimModuleSyntax": false
   },
   "include": ["src/**/*"],
   "exclude": ["node_modules", "__tests__"]