feat: Create injectFilesInMem util

Author: MagnunAVFAzion

lib/utils/index.js

@@ -17,6 +17,7 @@ import getUrlFromResource from './getUrlFromResource/index.js';
 import generateWebpackBanner from './generateWebpackBanner/index.js';
 import relocateImportsAndRequires from './relocateImportsAndRequires/index.js';
 import getExportedFunctionBody from './getExportedFunctionBody/index.js';
+import injectFilesInMem from './injectFilesInMem/index.js';
 
 export {
   copyDirectory,
@@ -38,4 +39,5 @@ export {
   VercelUtils,
   generateWebpackBanner,
   relocateImportsAndRequires,
+  injectFilesInMem,
 };

lib/utils/injectFilesInMem/index.js

@@ -0,0 +1,3 @@
+import injectFilesInMem from './injectFilesInMem.utils.js';
+
+export default injectFilesInMem;

lib/utils/injectFilesInMem/injectFilesInMem.utils.js

@@ -0,0 +1,51 @@
+import fs from 'fs/promises';
+import path from 'path';
+
+/**
+ * Reads files from a dir (recursively), mount an object with the files contents
+ * and generates a code to be used in the worker build process.
+ * This files mapping will be available in globalThis.\_\_FILES\_\_(worker memory).
+ * You can use fs module to retrieve this files.
+ * @param {string[]} dirs - paths of dirs to inject
+ * @returns {string} - the code to be injected in bundle process.
+ */
+async function injectFilesInMem(dirs) {
+  const result = {};
+
+  /**
+   * Read content from files and save in the result
+   * @param {string} dir - dir to read files;
+   */
+  async function readFilesRecursively(dir) {
+    const files = await fs.readdir(dir);
+
+    await Promise.all(
+      files.map(async (file) => {
+        const filePath = path.join(dir, file);
+        const stats = await fs.stat(filePath);
+
+        if (stats.isDirectory()) {
+          await readFilesRecursively(filePath);
+        } else if (stats.isFile()) {
+          const bufferContent = await fs.readFile(filePath);
+          let key = filePath;
+          if (!filePath.startsWith('/')) key = `/${filePath}`;
+          const bufferObject = JSON.stringify(bufferContent.toString('base64'));
+          result[key] = { content: bufferObject };
+        }
+      }),
+    );
+  }
+
+  await Promise.all(
+    dirs.map(async (dir) => {
+      await readFilesRecursively(dir);
+    }),
+  );
+
+  const codeToInject = `globalThis.__FILES__=${JSON.stringify(result)};`;
+
+  return codeToInject;
+}
+
+export default injectFilesInMem;