cli-testing-library

[WIP] CLI Testing Library

A testing library that allows you to test input and outputs of your CLI command.

Note: This is a work in progress. The API is likely going to change.

Terminal Text Parsing Support Checklist Refer to Full List of Ansi Escape Codes that need to be handled.

• Normal text without ansi escape codes
• Colored text
• Cursor movement (Basic Support. Not tested)
• Erase Line/Screen Clear (Basic Support. Not tested)
• Screen Modes (No Support)
• Private Modes (No Support)
• Multiple Arguments (No Support. Difficult to support this)

Installation

With NPM:

npm install --save-dev cli-testing-library 

With Yarn:

yarn add --dev cli-testing-library

Examples

Check out Interactive Examples on Stackblitz

Eg 1: Hello World Example

// hello-world.test.js
const { createCommandInterface } = require('cli-testing-library');

test('should print greetings', async () => {
  const commandInterface = createCommandInterface('node ./hello-world.js', {
    cwd: __dirname, // Directory from where you want to run the command 
  });
  await commandInterface.type('Saurabh\n');
  const terminal = await commandInterface.getOutput();
  expect(terminal.stringOutput).toBe("What's your name?Hi, Saurabh!");
});

The code that we're testing-

// hello-world.js
const readline = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout,
});

readline.question(`What's your name?`, (name) => {
  console.log(`Hi, ${name}!`);
  readline.close();
});

Eg 2: Tokenized Output

Check out this example of StackBlitz

Sometimes you may want to test if the output has correct color and graphics. You can use the .tokenizedOutput method to get tokens in the output.

Check out list of tokens that library outputs.

// colored-output.test.js
const { createCommandInterface } = require('cli-testing-library');

test('should have bold red text', async () => {
  const commandInterface = createCommandInterface('node ./colored-output.js', {
    cwd: __dirname,
  });
  const terminal = await commandInterface.getOutput();
  expect(terminal.tokenizedOutput).toBe("This has a [BOLD_START][RED_START]red and bold[COLOR_END][BOLD_END] text.");
});

More Examples on Stackblitz

Big Shoutout to

• @fnky for the list of all ansi escape codes.
• @netzkolchose for node-ansiterminal library.