file-icon/index.js

Get the icon of a file or app as a PNG image (macOS)

import process from 'node:process';
import path from 'node:path';
import {promisify} from 'node:util';
import {fileURLToPath} from 'node:url';
import {execFile} from 'node:child_process';
import pMap from 'p-map';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

const execFileP = promisify(execFile);
const binary = path.join(__dirname, 'file-icon');
const HUNDRED_MEGABYTES = 1024 * 1024 * 100;

const spawnOptions = {
	encoding: null,
	maxBuffer: HUNDRED_MEGABYTES,
};

const validate = (file, options) => {
	options = {
		size: 1024,
		...options,
	};

	if (process.platform !== 'darwin') {
		throw new Error('macOS only');
	}

	if (!file) {
		throw new Error('Specify one or an array of: app name, bundle identifier, file path, or pid');
	}

	if (typeof file !== 'string' && typeof file !== 'number' && !Array.isArray(file)) {
		throw new TypeError(`Expected \`file\` be a string, number, or an array, got \`${typeof file}\``);
	}

	if (Array.isArray(file) && !file.every(f => typeof f === 'string' || typeof f === 'number')) {
		throw new TypeError('Expected all members of `file` array to be of `string` or `number` type');
	}

	if (typeof options.size !== 'number') {
		options.size = 1024;
	}

	if (options.size > 1024) {
		throw new Error('Size must be 1024 or less');
	}

	return options;
};

const toArray = input => Array.isArray(input) ? input : [input];

const toCLIArgument = (file, {size, destination}) => {
	const toBuffer = file => ({appOrPID: file.toString(), size});
	const toFile = (file, index) => ({...toBuffer(file), destination: toArray(destination)[index]});

	// eslint-disable-next-line unicorn/no-array-callback-reference
	const argument_ = toArray(file).map(destination ? toFile : toBuffer);

	return JSON.stringify(argument_);
};

export async function fileIconToBuffer(file, options) {
	options = validate(file, options);

	const files = toArray(file);

	const mapper = async file => {
		const {stdout} = await execFileP(binary, [toCLIArgument(file, options)], spawnOptions);
		return stdout;
	};

	const buffers = await pMap(files, mapper, {concurrency: 8});

	return buffers.length === 1 && !Array.isArray(file)
		? buffers[0]
		: buffers;
}

export async function fileIconToFile(file, options) {
	options = validate(file, options);

	const isArray = Array.isArray(file);

	if ((typeof file === 'string' || typeof file === 'number') && typeof options.destination !== 'string') {
		throw new TypeError(`Expected \`options.destination\` to be of type \`string\` when \`file\` is of type \`string\` or \`number\`, got \`${typeof options.destination}\``);
	} else if (isArray && !Array.isArray(options.destination)) {
		throw new TypeError(`Expected \`options.destination\` to be of type \`array\` when \`file\` is of type \`array\`, got \`${typeof options.destination}\``);
	} else if (isArray && file.length !== options.destination.length) {
		throw new TypeError('Expected `file` and `options.destination` arrays to be of the same length');
	}

	await execFileP(binary, [toCLIArgument(file, options)], spawnOptions);
}