A simple check to see if a file exists, resolving to true or false, but creating the file regardless

fileExistsAndCreate.js

import fs from 'fs';

/**
 * Accepts a full file path and checks whether the file exists returning the answer
 * If it doesnt exist it will also attempt to create the file.
 *
 * @param {string} filepath The file to check and create.
 */
export const fileExistsAndCreate = filepath => {
	return new Promise((resolve, reject) => {
		fs.open(filepath, 'wx', (err, fd) => {
			if (err) {
				if (err.code === 'EEXIST') {
					resolve(true);
					return;
				}
				reject(err);
				return;
			}

			resolve(false);
			// writeMyData(fd);
		});
	});
};

fileExistsAndCreate.test.js

import fs from 'fs';
import path from 'path';
import { fileExistsAndCreate } from './fileExistsAndCreate';

test('File exists', async () => {
	const filepath = path.join(__dirname, 'fileExists.test.js');

	const exists = await fileExistsAndCreate(filepath);

	expect(exists).toBe(true);
});

test('File didnt exist but is created', async () => {
	const filepath = path.join(__dirname, 'an-other-file.txt');

	const originallyExists = await fileExistsAndCreate(filepath);
	const nowExists = fs.existsSync(filepath);
	fs.unlinkSync(filepath);

	expect(originallyExists).toBe(false);
	expect(nowExists).toBe(true);
});