Overview

Micro-Jest is a tiny JavaScript testing framework for Kaluma. It is distilled version of the original Jest project.

Install

Install package with NPM.

$ npm install https://github.com/niklauslee/micro-jest --save

Usage

Here is a simple example. Different from Jest, you have to call done() always even if the test case is synchronous.

const { test, expect, start } = require("micro-jest");

function sum(a, b) {
  return a + b;
}

test("adds 1 + 2 to equal 3", (done) => {
  expect(sum(1, 2)).toBe(3);
  done(); // should be called
});

start(); // start to test

Using Matchers

Micro-Jest provides various matchers to test values. toBe() is used to test a value with exact equality.

test("1 + 1 = 2", (done) => {
  expect(1 + 1).toBe(2);
  done();
});

Here is the matchers provided.

• expect(value).toBe(value)
• expect(value).notToBe(value)
• expect(value).toBeTruthy()
• expect(value).toBeFalsy()
• expect(number).toBeGreaterThan(number)
• expect(number).toBeGreaterThanOrEqual(number)
• expect(number).toBeLessThan(number)
• expect(number).toBeLessThanOrEqual(number)
• expect(array).toContain(value)
• expect(array).notToContain(value)
• expect(string).toMatch(regex)
• expect(string).notToMatch(regex)
• expect(function).toThrow([message])
• expect(function).notToThrow()

Running tests

To run all test cases you have to call jest.start().

However sometimes you want to run a particular test case rather than all test cases. You can do it by calling start() with a number of test case.

jest.start(0); // Run the first test case.
jest.start(3); // Run the 4-th test case.
jest.start(); // Run all the test cases.

Handling errors

If you catch an error you can pass it to done() callback.

// async
test('adds 1 + 2 to equal 3', (done) => {
  someAsyncFunction(err => {
    if (err) {
      done(err);
    } else {
      expect(...).toBe(...);
      done();
    }
  })
});

// sync
test('adds 1 + 2 to equal 3', (done) => {
  try {
    someSyncFunction();
    done();
  } catch(err) {
    done(err);
  }
});