fix: add utility functions to get module type

packages/artillery/lib/util/prepare-test-execution-plan.js

@@ -2,6 +2,7 @@ const csv = require('csv-parse');
 const fs = require('node:fs');
 const path = require('node:path');
 const p = require('util').promisify;
+const { isPackageESM } = require('@artilleryio/int-core').util;
 
 const {
   readScript,
@@ -118,6 +119,8 @@ function replaceProcessorIfTypescript(script, scriptPath) {
     return script;
   }
 
+  const packageType = isPackageESM(scriptPath) ? 'esm' : 'cjs';
+
   const actualProcessorPath = path.resolve(
     path.dirname(scriptPath),
     relativeProcessorPath
@@ -140,7 +143,7 @@ function replaceProcessorIfTypescript(script, scriptPath) {
       outfile: newProcessorPath,
       bundle: true,
       platform: 'node',
-      format: 'cjs',
+      format: packageType,
       sourcemap: 'inline',
       external: ['@playwright/test', ...userExternalPackages]
     });

packages/core/index.js

@@ -94,5 +94,6 @@ module.exports = {
   engine_http: require('./lib/engine_http'),
   ssms: require('./lib/ssms'),
   isIdlePhase: require('./lib/is-idle-phase'),
-  updateGlobalObject
+  updateGlobalObject,
+  util: require('./lib/util')
 };

packages/core/lib/runner.js

@@ -13,6 +13,7 @@ const uuidv4 = require('uuid').v4;
 const { SSMS } = require('./ssms');
 const createPhaser = require('./phases');
 const createReader = require('./readers');
+const { isPackageESM } = require('./util');
 const engineUtil = require('@artilleryio/int-commons').engine_util;
 const wl = require('./weighted-pick');
 const { pathToFileURL } = require('url');
@@ -83,7 +84,7 @@ async function loadProcessor(script, options) {
       script.config.processor
     );
 
-    if (processorPath.endsWith('.mjs')) {
+    if (isPackageESM(processorPath)) {
       const fileUrl = pathToFileURL(processorPath);
       const exports = await import(fileUrl.href);
       script.config.processor = Object.assign(

packages/core/lib/util.js

@@ -0,0 +1,63 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const path = require('path');
+const fs = require('fs');
+
+function determineModuleTypeByPackageJson(filePath) {
+  // If it's .js, we need to check the package.json
+  try {
+    // Start from script directory and move up until we find package.json
+    let dir = path.dirname(filePath);
+    while (dir !== path.parse(dir).root) {
+      try {
+        const pkgPath = path.join(dir, 'package.json');
+        const pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf8'));
+        return pkg.type === 'module' ? 'esm' : 'commonjs';
+      } catch (err) {
+        dir = path.dirname(dir);
+      }
+    }
+
+    // No package.json found, default to commonjs
+    return 'commonjs';
+  } catch (err) {
+    return 'commonjs';
+  }
+}
+
+function determineModuleType(filePath) {
+  if (filePath.endsWith('.mjs')) return 'esm';
+  if (filePath.endsWith('.cjs')) return 'commonjs';
+
+  return determineModuleTypeByPackageJson(filePath);
+}
+
+/**
+ * Determine if a package is ESM or not.
+ * @param {string | undefined} filePath Path to the package.json file. If not provided, it will default to the current working directory.
+ * @returns A boolean indicating if the package is ESM or not.
+ */
+function isPackageESM(filePath) {
+  if (!filePath) filePath = process.cwd();
+
+  return determineModuleType(filePath) === 'esm';
+}
+
+/**
+ * Determine if a package is CommonJS or not.
+ * @param {string | undefined} filePath Path to the package.json file. If not provided, it will default to the current working directory.
+ * @returns A boolean indicating if the package is CommonJS or not.
+ */
+function isPackageCommonJS(filePath) {
+  if (!filePath) filePath = process.cwd();
+
+  return determineModuleType(filePath) === 'commonjs';
+}
+
+module.exports = {
+  determineModuleType,
+  isPackageESM,
+  isPackageCommonJS
+};