@applicvision/js-toolbox/src/find-files.js

#! /usr/bin/env node
import fs from 'fs/promises'
import path from 'path'

async function readGitignore() {
	try {
		const gitIgnore = `${await fs.readFile('.gitignore')}`
		return gitIgnore.split('\n').filter(file => file)
	} catch (e) {
		if (e.code !== 'ENOENT') {
			throw e
		}
		return []
	}
}

async function scanDirectory(directory, ignoreSet, fileMatcher) {
	const entries = await fs.readdir(directory, { withFileTypes: true })

	const filtered = entries
		.filter(entry => !entry.name.startsWith('.'))
		.filter(entry => !ignoreSet.has(entry.name))

	const found = await Promise.all(filtered.map(async entry => {
		if (entry.isDirectory()) {
			const directoryPath = path.join(directory, entry.name)
			return ignoreSet.has(directoryPath) ? [] : scanDirectory(directoryPath, ignoreSet, fileMatcher)
		}
		return fileMatcher(entry.name) ? path.join(directory, entry.name) : []
	}))
	return found.flat()
}

export async function findFiles(directory, ignored = new Set(), fileMatcher = () => true) {
	const gitIgnores = await readGitignore()
	gitIgnores.forEach(ignore => ignored.add(ignore))
	return scanDirectory(directory, ignored, fileMatcher)
}