README.md

@zumerbox/tests

This tool simplifies the process of running Jest tests for your project, including visual tests with image snapshots. It provides a convenient way to execute Jest with custom configuration and setup files, allowing you to run tests with ease.

Visual test are a convenient way to test UI. In this case, image snapshoots are compared to detect changes.

Refer to the ZumerBox bundle for more information and tools.

Features

• Headless DOM with jsdom
• Visual diff testing with Puppeteer + pixelmatch
• Out of the box: zero configuration required in the user’s project

Installation & Usage

Run directly without prior installation:

npx @zumerbox/tests

By default, Mocha will discover test files matching test/**/*.test.{js,ts,jsx,tsx}.

Writing Tests

Unit / Logic Tests

// test/math.test.js
const { expect } = require('chai');

describe('Math Operations', () => {
  it('should add numbers correctly', () => {
    expect(1 + 2).to.equal(3);
  });
});

Visual UI Tests

// test/button.test.js
describe('Button UI', () => {
  it('matches the visual snapshot', async function() {
    await this.page.setContent('<button class="primary">Click me</button>');
    await visualDiff(this.page, 'button-primary.png');
  });
});

• On the first run, a new snapshot __snapshots__/button-primary.png will be generated.
• Subsequent runs compare against the baseline and, if discrepancies are found, output a diff image *.diff.png and fail the test.

Optional Flags

• --u: Regenerate all baseline snapshots.

npx @zumerbox/tests --update-snapshots
npx @zumerbox/tests --grep "Button UI"