fix: remove reference to __dirname

The builtin __dirname is not available for ES modules.

babel.config.cjs

@@ -0,0 +1,28 @@
+const test = process.env.NODE_ENV === 'test';
+
+module.exports = {
+    "presets": [
+        "@babel/preset-typescript",
+        [
+            "@babel/preset-env",
+            {
+                "useBuiltIns": "entry",
+                "corejs": 3,
+                "targets": {
+                    "node": "current"
+                }
+            }
+        ]
+    ],
+    "plugins": [
+        function () {
+            return {
+                visitor: {
+                    MetaProperty(path) {
+                        path.replaceWithSourceString("__filename")
+                    }
+                }
+            }
+        }
+    ]
+};

package.json

@@ -39,12 +39,14 @@
   "devDependencies": {
     "@babel/core": "^7.24.5",
     "@babel/preset-env": "^7.24.5",
+    "@babel/preset-typescript": "^7.24.1",
     "@rollup/plugin-typescript": "^11.1.6",
     "@swc/cli": "^0.3.9",
     "@swc/core": "^1.4.2",
     "@types/jest": "^29.5.12",
     "@types/node": "^20.12.8",
     "babel-loader": "^9.1.3",
+    "babel-plugin-transform-import-meta": "^2.2.1",
     "copyfiles": "^2.4.1",
     "jest": "^29.7.0",
     "npm-run-all": "^4.1.5",
@@ -58,7 +60,13 @@
   },
   "jest": {
     "transform": {
-      "^.+\\.ts?$": "ts-jest"
+      "^.+\\.ts?$": [
+        "ts-jest",
+        {
+          "babelConfig": true,
+          "useESM": true
+        }
+      ]
     },
     "testEnvironment": "node",
     "testRegex": "/tests/.*\\.(test|spec)?\\.(ts|tsx)$",

src/gptscript.ts

@@ -773,7 +773,8 @@ async function getCmdPath(): Promise<string> {
 	}
 
 	const path = await import("path")
-	return path.join(__dirname, "..", "bin", "gptscript")
+	const url = await import("url")
+	return path.join(path.dirname(url.fileURLToPath(import.meta.url)), "..", "bin", "gptscript")
 }
 
 export function listTools(gptscriptURL?: string): Promise<string> {