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Overview

The getFileTree function recursively scans a directory and returns a formatted array of file and directory paths. It automatically excludes common build and dependency directories.

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Function Signature

getFileTree(dir: string, prefix?: string): string[]

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Parameters

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dir
string
required
The directory path to scan. Can be relative or absolute. Relative paths are resolved from the current working directory.
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prefix
string
default:"''"
Internal parameter used for indentation during recursive calls. Generally not provided by users. Defaults to an empty string.

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Return Value

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tree
string[]
An array of strings representing the file tree structure. Directories are suffixed with / and subdirectories/files are indented with two spaces per level.

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Implementation Details

The function performs the following steps:
  1. Reads the directory contents using fs.readdirSync()
  2. Filters out directories listed in the IGNORED_DIRS array
  3. For each item:
    • If it’s a directory: adds it with a / suffix and recursively scans it with increased indentation
    • If it’s a file: adds it to the results with current indentation
  4. Returns the complete tree as an array of formatted strings

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Ignored Directories

The following directories are automatically excluded from the file tree: 
const IGNORED_DIRS = ['.git', 'node_modules', 'dist', 'build', '.next'];
These directories are commonly used for version control, dependencies, and build artifacts. Excluding them significantly improves performance and readability when scanning project directories.

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Usage Example

import { getFileTree } from './tools/getFileTree';

// Get file tree for current directory
const tree = getFileTree('.');
console.log(tree.join('\n'));

// Get file tree for specific directory
const srcTree = getFileTree('./src');
srcTree.forEach(line => console.log(line));

// Example output:
// src/
//   index.ts
//   utils/
//     helper.ts
//     validator.ts
//   components/
//     Button.tsx

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Output Format

The function returns an array where:
  • Each directory is suffixed with /
  • Each level of nesting adds two spaces of indentation
  • Files and directories are listed in the order they appear in the file system
[
  'src/',
  '  index.ts',
  '  components/',
  '    Header.tsx',
  '    Footer.tsx',
  '  utils/',
  '    format.ts'
]

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Error Handling

This function will throw an error if:
  • The directory does not exist
  • The directory cannot be read due to permissions
  • The path points to a file instead of a directory
This is a synchronous recursive operation and will block the event loop until the entire directory tree is scanned. For very large directory structures, this may take noticeable time.

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Practical Applications

import { getFileTree } from './tools/getFileTree';
import { writeFile } from './tools/writeFile';

// Generate project structure documentation
const tree = getFileTree('./src');
const docs = `# Project Structure\n\n\`\`\`\n${tree.join('\n')}\n\`\`\``;
writeFile('./STRUCTURE.md', docs);

// Find all TypeScript files
const tree = getFileTree('.');
const tsFiles = tree.filter(line => line.trim().endsWith('.ts'));
console.log('TypeScript files:', tsFiles);

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Source Code

import fs from 'fs';
import path from 'path';

const IGNORED_DIRS = ['.git', 'node_modules', 'dist', 'build', '.next'];

export const getFileTree = (dir: string, prefix = ''): string[] => {
  let results: string[] = [];
  const list = fs.readdirSync(dir);

  list.forEach(file => {
    if (IGNORED_DIRS.includes(file)) return;
    const filePath = path.join(dir, file);
    const stat = fs.statSync(filePath);

    if (stat.isDirectory()) {
      results.push(prefix + file + '/');
      results = results.concat(getFileTree(filePath, prefix + '  '));
    } else {
      results.push(prefix + file);
    }
  });

  return results;
};

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