chore: verifies the module system before import config file

It imports the package.json from projectDirectory to check the module system,
ECMAScript Modules or CommonJS. If the  module system is ESM then just import
the eventcatalog.config.js. Otherwise, make a copy of eventcatalog.config.js
to the tmpdir/eventcatalog.config.mjs and import it.
It removes the convertEsmToCjs used before.

scripts/__tests__/eventcatalog-config-file-utils.spec.ts

@@ -10,6 +10,7 @@ import {
   verifyRequiredFieldsAreInCatalogConfigFile,
   writeEventCatalogConfigFile,
 } from 'scripts/eventcatalog-config-file-utils';
+import { tmpdir } from 'os';
 
 describe('catalog-to-astro-content-directory', () => {
   afterEach(async () => {
@@ -101,11 +102,11 @@ describe('catalog-to-astro-content-directory', () => {
         })
       );
     });
-    it('eventcatalog.config.cjs (temp commonjs file) is removed when fetching the catalog file', async () => {
+    it('removes eventcatalog config from the tmpdir', async () => {
       await getEventCatalogConfigFile(CATALOG_DIR);
 
-      const commonJsFile = path.join(CATALOG_DIR, 'eventcatalog.config.cjs');
-      expect(existsSync(commonJsFile)).toBe(false);
+      const configFile = path.join(tmpdir(), 'eventcatalog.config.mjs');
+      expect(existsSync(configFile)).toBe(false);
     });
   });
 

scripts/__tests__/example-catalog/package.json

@@ -0,0 +1,3 @@
+{
+  "description": "Only for testing purposes"
+}

scripts/eventcatalog-config-file-utils.js

@@ -1,64 +1,34 @@
 import { readFile, writeFile, rm } from 'node:fs/promises';
-import { existsSync } from 'fs';
+import { existsSync } from 'node:fs';
+import { copyFile } from 'node:fs/promises';
 import path from 'node:path';
 import { v4 as uuidV4 } from 'uuid';
 import { pathToFileURL } from 'url';
+import { tmpdir } from 'node:os';
 
-// * Very strange behavior when importing ESM files from catalogs into core.
-//  * Core (node) does not know how to handle ESM files, so we have to try and convert them.
-//  *
-//  * This needs sorting out! Sorry if you are reading this, but it unblocked me for now!
-//  * @param {*} content
-//  * @returns
-//  */
-function convertESMtoCJS(content) {
-  // Replace import statements with require
-  content = content.replace(/import\s+([a-zA-Z0-9{},\s*]+)\s+from\s+['"]([^'"]+)['"];/g, (match, imports, modulePath) => {
-    return `const ${imports.trim()} = require('${modulePath}');`;
-  });
-
-  // Replace export default with module.exports
-  content = content.replace(/export\s+default\s+/g, 'module.exports = ');
-
-  // Replace named exports with module.exports
-  content = content.replace(/export\s+{([^}]+)}/g, (match, exports) => {
-    return `module.exports = {${exports.trim()}};`;
-  });
-
-  // Remove declarations of __filename and __dirname
-  content = content.replace(/^\s*(const|let|var)\s+__(filename|dirname)\s+=\s+.*;?\s*$/gm, '');
-
-  return content;
-}
-
-export async function cleanup(projectDirectory) {
-  const filePath = path.join(projectDirectory, 'eventcatalog.config.cjs');
+export async function cleanup() {
+  const filePath = path.join(tmpdir(), 'eventcatalog.config.mjs');
   if (existsSync(filePath)) {
     await rm(filePath);
   }
 }
 
 export const getEventCatalogConfigFile = async (projectDirectory) => {
   try {
-    const rawFile = await readFile(path.join(projectDirectory, 'eventcatalog.config.js'), 'utf8');
-
-    // Have to conver the ESM to CJS...
-    const configAsCommonJS = convertESMtoCJS(rawFile);
+    let configFilePath = path.join(projectDirectory, 'eventcatalog.config.js');
 
-    await writeFile(path.join(projectDirectory, 'eventcatalog.config.cjs'), configAsCommonJS);
+    const packageJson = await import(/* @vite-ignore */ path.join(projectDirectory, 'package.json'));
+    if (packageJson.default?.type !== 'module') {
+      await copyFile(configFilePath, path.join(tmpdir(), 'eventcatalog.config.mjs'));
+      configFilePath = path.join(tmpdir(), 'eventcatalog.config.mjs');
+    }
 
-    const configFilePath = path.join(projectDirectory, 'eventcatalog.config.cjs');
     const configFileURL = pathToFileURL(configFilePath).href;
-    const configAsCJS = await import(/* @vite-ignore */ configFileURL);
-
-    //  Clean up?
-    await writeFile(path.join(projectDirectory, 'eventcatalog.config.js'), rawFile);
-
-    await cleanup(projectDirectory);
+    const config = await import(/* @vite-ignore */ configFileURL);
 
-    return configAsCJS.default;
-  } catch (error) {
-    await cleanup(projectDirectory);
+    return config.default;
+  } finally {
+    await cleanup();
   }
 };
 
@@ -92,10 +62,8 @@ export const writeEventCatalogConfigFile = async (projectDirectory, newConfig) =
 
     // Write the updated content back to the file
     await writeFile(configFilePath, content);
-
-    await cleanup(projectDirectory);
-  } catch (error) {
-    await cleanup(projectDirectory);
+  } finally {
+    await cleanup();
   }
 };