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A less than 200 lines of code javascript test harness for nodejs and the browser


Table of Contents


npm install --save-dev zora


Zero config

It is just Javascript, write your program, bundle it (if needed) for the environment you want to test in and execute the script ! No whatever.conf.js

No global

There is no global, just a function providing a two methods api.

Async testing made easy

Use the Javascript native AsyncFunction to write your asynchronous code as it was synchronous. No need for a callback or to plan ahead.

plan.test('my async test',async function (assert){
    const resolvedResult = await db.findUser('foo');
    assert.deepEqual(resolvedResult, {name:'foo'}, 'should have fetched mister foo');


Each test run in parallel. It will likely be faster than other sequential test runners like tape for example. It therefore enforces you to write your tests in isolation which is often a good practice.


Zora does not do rocket science but seems to be the fastest among mocha, tape, ava, jest on my machine according to a benchmark I have set up The test is pretty simple: a test suite split into 20 files with 20 tests with an assertion in a nodejs environment. Anyway you can simply fork the repo and sort it out yourself.

tap (Test Anything Protocol) producer

By default zora produces a tap report through the console, so you can pipe in with any tap reporter.

browser friendly

No sophisticated or platform specific (nodejs) dependency in it. Just regular es2016 Javascript. You bundle your test program with your favorite module bundler as you would do for you app anyway, and drop it in a browser (or use browser friendly tap reporter).


simple case one file

import zora from 'zora';
// you create a test plan
const plan = zora();
    .test('a test',(assertion) => {
    .test('another test',(assertion) => {
    .run(); // you run it

multiple files setup (recommended)

You might want to split your tests in various files. The recommended way is to make each file exports its own plan... and create a plan of plans. The main advantages are:

  • you'll be able to run your test files separately with the command line tool
  • you'll have a single entry point which makes things easier if you want to use a module bundler for example
import zora from 'zora';
const plan = zora();
    .test('a test',(assertion) => {
    .test('another test', (assertion) => {
export default plan; // export the plan

Then in you entry point

import zora from 'zora';
import plan from './test1.js'; // import all your test plans
// you create a test plan
const masterPlan = zora();
    .run(); // and run your plans (you can omit this line if you want use the command line tool)

In the browser

Zora itself does not depend on native nodejs modules (such file system, processes, etc) so the code you will get is regular es2016 code. The only thing to do is probably to bundle your test script with your favourite module bundler (you might want to transpile your code as well for older browsers).

You can find some recipes here

drop in file

You can simply drop the dist file in the browser (I'll add into CDN if people want it) and write your script below (or load it). You can for example play with this codepen

<!-- some content -->
<script src="path/to/zora.js"></script>
<!-- your test code -->
      .test('some test', function*(assert) {
        assert.ok(true, 'hey there');
      .test('some failing test', function*(assert) {'it failed');
<!-- some content -->

Use tools that load files for you in a browser (ex karma)

Same than above but you can ask a runner to handle for you the browsers processes, the bundling/transpilation if any, etc


As part of CI (example with rollup)

I will use rollup for this example, but you should not have any problem with webpack or browserify. The idea is simply to create a test file your testing browsers will be able to run.

assuming you have your entry point as follow :

import zora from 'zora';
import test1 from './test1.js'; // some tests here
import test2 from './test2.js'; // some more tests there
import test3 from './test3.js'; // another test plan 
const plan = zora()

where for example ./test/test1.js is

import zora from 'zora';
const plan = zora()
    .test('mytest',function * (assertions){
    .test('mytest',function * (assertions){
export default plan;

At the time of writing the browsers probably won't understand the ES module syntax so we need to bundle our test file. Using rollup, we would have the following configuration (for more info follow the tutorial serie)

const node = require('rollup-plugin-node-resolve');
const commonjs = require('rollup-plugin-commonjs');
module.exports = {
  entry: './test/index.js',
  dest: './test/dist/index.js',
  format: 'iife', //iife as the code will run in the browser
  plugins: [node(), commonjs()], //you can add babel plugin if you need transpilation

and that'is it. You can now drop you ./test/dist/index.js in a html document and open it in the browser. You should see something like this in the console tap output in the browser console

Even better, you can use tap reporter browser friendly such tape-run so you'll have a proper exit code depending on the result of your tests.

so all together, in your package.json you can have something like that

// ...
  "scripts": {
    "test": "rollup -c ./test/rollup.config.js && cat ./test/dist/index.js | tape-run"
// ...

Use output data not as a tap output

// TODO add a different sink generator example

Assertions API

The assertion api you can use within your test coroutines is pretty simple and highly inspired from tape

  • ok
  • notOk
  • equal
  • notEqual
  • deepEqual
  • notDeepEqual
  • throws
  • doesNotThrow
  • fail

You can use any other assertion library as well but a failing assertion will likely throw an exception which won't be properly tape reported