refactor: create dirTree.js

src/utils/dirTree.js

@@ -0,0 +1,50 @@
+import { promises as fs } from 'fs';
+import { join } from 'path';
+
+/**
+ * @typedef {object} DirTreeNode
+ *
+ * @property {string} name The name of the node.
+ * @property {Array<DirTreeNode>} [children] The array of child nodes if the node is a directory. This is a recursive structure.
+ */
+
+/**
+ * Asynchronously retrieves the directory tree structure.
+ *
+ * @async
+ * @param {string} dirPath The path of the directory.
+ * @returns {Promise<Array<DirTreeNode>>} A promise that resolves to an array of `DirTreeNode`.
+ *
+ * @example
+ * // Get the directory tree structure
+ * const dirTree = await getDirTree('/path/to/dir');
+ * console.log(dirTree);
+ */
+export async function getDirTree(dirPath) {
+  // `readdir` automatically throws an error when `dirPath` is not a directory.
+  const dirents = await fs.readdir(dirPath, { withFileTypes: true });
+
+  return await Promise.all(
+    dirents.map(async dirent => ({
+      name: dirent.name,
+      ...(dirent.isDirectory()
+        ? { children: await getDirTree(join(dirPath, dirent.name)) }
+        : {}),
+    })),
+  );
+}
+
+/**
+ * Checks if a `DirTreeNode` is a directory.
+ *
+ * @param {DirTreeNode} dirTreeNode The `DirTreeNode` object.
+ * @returns {boolean} `true` if the node is a directory. otherwise, `false`.
+ *
+ * @example
+ * // Check if a node is a directory
+ * const isDir = isDirectory({ name: 'folder', children: [...] });
+ * console.log(isDir); // true
+ */
+export function isDirectory(dirTreeNode) {
+  return Boolean(dirTreeNode.children);
+}