@amindunited/read-file/src/read-file.test.js

A Promise wrapper around fs.readFile

/**
 * @license
 * Copyright Robin Buckley. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file
 */
'use strict';

const fs = require('fs');
const readFile = require('./index');
const expect = require('chai').expect

const expectedContent = 'Hey';
const testFilePath = './read-file-promise-test-file.js';

describe('Read File Promise', () => {

  beforeEach(() => {
    const promise = new Promise((resolve, reject) => {
      fs.writeFile(testFilePath, expectedContent, 'utf8', (err, contents) => {
        if (!err) {
          resolve(contents);
        } else {
          throw(err);
          reject(err);
        }
      });
    });
    return promise;
  });

  after(() => {
    const promise = new Promise((resolve, reject) => {
      fs.stat(testFilePath, (err, stats) => {
        if (err) {
          return reject(err);
        }
        if (stats.isFile()) {
          fs.unlink(testFilePath, (err) => {
            if (err) {
              return reject(err);
            }
            return resolve();
          });
        }
      });
    });
    return promise;
  });

  it('should export a function', () => {
    expect(readFile).to.be.a('function');
  });

  it('should return a promise', () => {
    expect(readFile(testFilePath).then).to.be.a('function');
  });

  it('should handle an error', () => {
    readFile('/no-a-real-file.fake')
      .then(
        () => {},
        (err) => {
          expect(true).to.be.equal(true);
        }
      );
  });

  it('should read a file', () => {
    readFile(testFilePath).then((content) => {
      expect(content).to.equal(expectedContent);
    });
  });

});