Pico Tester

Pico Tester is a small and fast spec runner for Javascript. Mocha, Jest, etc. bring too much burden along, either from history or features. This library is a reset. Using the least needed for a test runner. Also in terms of dependencies pico-tester tries to use the least needed.

Here is where I first sketched the idea. In short, pico-tester is a tool to:

• improve the speed of the TDD cycle
• focus on one test at a time
• be fast
• ESM first (anything that is no ECMAScript module is not intended to work, migrate forward, not back)

See the ADRs and tenets below for understanding what drives and steers this project.

History - The Real Kavun

The project is a fork of @SengitU's project Kavun. He started this project during his apprenticeship at HolidayCheck, to build a tiny, lightweight test runner, to figure out what a test runner really just needs.

Installation

npm install pico-tester

Usage Examples

• Run the tests just for one file do
  pt test-files.spec.js
• or multiple files
  py test1.spec.js 2.spec.js test/3.spec.js
• or for all .js files (use you command line's file grep features, e.g. * or ** etc.)
  pt *.js
• for all files found in root and up to 2 sub-directories, ending in .js
pt {,**,**/**}/*.js
• and mix any of the above
  pt test-files.spec.js {,**,**/**}/*.js

Pico-tester does not contain any file-grep functionality. Use your command line's grep and/or file finding features. This was done to reduce complexity.

Parameters

The command line takes:

1. any number of files (no directories!) to run as parameters
2. and NO other parameters!

Unit

A sync example for unit

import assert from 'assert';
import { it } from 'pico-tester';

it('Example `it`', () => {
  const expected = 2;
  const actual = 2;
  assert.equal(actual, expected);
});

An async example with async/await

import assert from 'assert';
import { it } from 'pico-tester';

it('Example async `it` with async / await', async () => {
  const actual = () => new Promise(resolve => resolve(true));
  const expected = true;
  const result = await actual();
  
  assert.equal(expected, result);
});

An async example with Promise, don't forget to return the promise

import assert from 'assert';
import { it } from 'pico-tester';

it('Example async `it` with async / await', () => {
  const actual = () => new Promise(resolve => resolve(true));
  const expected = true;
  
  return actual().then(result => assert.equal(expected, result));
});

Timeout

Timeout for each spec is 1500 miliseconds by default. To increase this amount, timeout attribute inside of the options object should be provided to the unit, as shown in the example;

it('Example `it` with extended timeout', async () => {
  const actual = () => new Promise(resolve => setTimeout(() => resolve(true), 1700));
  const expected = true;

  const result = await actual();
  assert.equal(expected, result);
}, { timeout: 2000 });

Spec

import assert from 'assert';
import { describe, it } from 'pico-tester';

describe('Example Spec', () => {
  it('unit', () => {
    const expected = 2;
    const actual = 2;
    assert.equal(actual, expected);
  });

  describe('Async', () => {
    it('with async / await', async () => {
      const actual = () => new Promise(resolve => resolve(true));
      const expected = true;

      const result = await actual();

      assert.equal(expected, result)
    });
  });
});

Tenets

1. In doubt solve it without a new dependency.
2. In doubt don't add a new feature, rather remove one.
3. Prefer speed.
4. Be compatible to mocha-style test libs, allowing well written tests overrules.

Development

The following describes how to (help) develop this code.

Setup and run

Project requires NodeJS to be installed. Even better to be compatible and prevent hazzle to install global stuff, use docker and that sets up the entire environment.

Here is how to do it:

• cd <here>
• docker-compose up -d - start the needed docker container(s), contains nodejs, smoke, all tools needed for this project
• docker-compose exec node bash - open a shell in the container named "node" where all is set up and you can start to work
• npm i to install
• npm test to run all the tests
• npm test:smoke to run all the smoke tests written using smoke "An integration test framework for practically anything."
• develop ...

The source files are mounted into the container (see the docker-compose.yml file) so you can edit in your favourite editor on your system and the docker container uses the same files, they are mounted into there. So be aware, removing files inside the container also removes them here.

Releasing

You want to know if you are ready to release a new version. Run npm run releasable --silent, this starts a script that checks the CHANGELOG.md, which is the project's to-do list! What, to-do list? Yes. See below how and why?

To release a new version run npm run release (not npm version!), this will include the checks described and do the release and versioning (read more below).

Recommended Development Process

This project uses the to-do-list-checker. The development process is also described there and will be followed in this project too.