README.md

Experiment #2 - Testing Node.js CLI tool

Popular packages:

• Inquirer: npm | github
• Oclif: npm | github | web

Playing with the native built in readline

Update: Don't waste your time for native readline, use inquirer! ;)

Task:

• Show an instruction about requesting name and age. Please fill in the following form.
• Show prompt and request a name. Name? >
• Wait for the prompt and ask age. Age? >
• Write back the given data using a terminal table format, like

name	age
Joe	25

Implementation

Instead of using the built in readline, there is a great wrapper: inquirer.

Writing test, mocking with jest

• We have to mock inquirer and inquirer.prompt.

import inquirer from 'inquirer';
jest.mock('inquirer')

test('some test', () => {
  inquirer.prompt = jest.fn().mockResolvedValue({ questionName: 'answer' });

  const result = await myAsyncMethod();
  expect(result).toEqual('answer');
}

Using inquirer

• Setup Question[] array:

const questions: Question[] = [{ message: 'The question', name: 'questionName' }]

• Prompt

const answers: Answers = await prompt(questions);

That's it.

Using oclif

• oclif tutorial: https://oclif.io/docs/introduction.html