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Version: 2022.4

Genesis Foundation testing

foundation-testing provides shared unit and e2e testing functionality.

API Docs

Unit Testing with UVU

Unit testing is provided by UVU.

UVU features

  • super lightweight
  • extremely performant
  • individually executable test files
  • supports async/await tests
  • supports native ES modules
  • browser-compatible
  • familiar API

E2E testing with Playwright

E2E testing is provided by Playwright

Playwright features

Playwright enables you to perform a number of very useful functions.

  • Run tests across all browsers.
  • Execute tests in parallel.
  • Enjoy context isolation out of the box.
  • Capture videos, screenshots and other artifacts on failure.
  • Integrate your POMs as extensible fixtures.

Test organisation

Unit testing specific logic can be done by adding a test file alongside the source file.


If your test spans more than one file or is more of an end-to-end test, you could wish to add your test to your package's /test directory instead. An example structure might be:

├── src 
│ └── logic.ts
│ └── logic.test.ts
│ └── component.ts
│ └── component.test.ts
├── test
│ └── e2e
│ └── baseline.e2e.ts
│ └── unit
│ └── baseline.test.ts
├── jsdom.setup.ts
├── package.json
└── playwright.config.ts

The contents of the jsdom.setup.ts file for your package could simply be:

export * from '@genesislcap/foundation-testing/jsdom';

The contents of the playwright.config.ts file for your package could include:

import { PlaywrightTestConfig } from '@playwright/test';
const config: PlaywrightTestConfig = {
testMatch: '**/*.e2e.ts',
globalSetup: '@genesislcap/foundation-testing/playwright', // returns teardown
projects: [
name: 'Chrome Stable',
use: {
browserName: 'chromium',
channel: 'chrome',
export default config;

Test scripts

You could add the following test-related scripts to the package.json file for your package:

"test": "npm run test:unit && npm run test:e2e",
"test:coverage": "c8 --include=src npm run test:unit",
"test:coverage:report": "npm run test:coverage && c8 report --reporter=text-lcov > coverage.lcov",
"test:coverage:report:nyc": "npm run test:unit:browser -- --cov && npx nyc report --reporter=html",
"test:e2e": "npx playwright test --config=./playwright.config.ts",
"test:e2e:debug": "cross-env PWDEBUG=1 npm run test:e2e",
"test:unit": "npm run test:unit:node",
"test:unit:browser": "playwright-test \"./**/*.test.ts\" --runner uvu",
"test:unit:browser:watch": "npm run test:unit:browser -- -w -d",
"test:unit:node": "npm run test:unit:node:src && npm run test:unit:node:test",
"test:unit:node:src": "uvu -r tsm -r esm -r ./jsdom.setup.ts ./src \".*.test.ts\"",
"test:unit:node:test": "uvu -r tsm -r esm -r ./jsdom.setup.ts ./test/unit \".*.test.ts\"",
"test:unit:watch": "watchlist src test -- npm run test:unit"

To provide the dev dependencies for these test scripts, you need to install:

@playwright/test playwright-test c8 esm jsdom tsm uvu watchlist

We are working on enhancing the genx cli to abstract test running, so you can offload this setup and tasks.

Testing logic

The logic.test.ts will probably use createLogicSuite, which is used to test function output given certain input arguments. Based on user feedback, these arguments are now passed as an array by convention:

// logic.test.ts
import { createLogicSuite } from '@genesislcap/foundation-testing';
import { myFunction } from './logic';

const Suite = createLogicSuite('myFunction');
Suite('myFunction should provide expected results', ({ runCases }) => {
runCases(myFunction, [
[['1'], true],
[[123], true],
[['60%'], true],
[['$60'], false],
[['1.1'], false],
[[''], false],
[[true], false],
[[null], false],
[[undefined], false],

Testing components

The component.test.ts file or any test that directly or indirectly uses the DI will also use createComponentSuite. Apart from setting up and tearing down your element fixture with a wrapping design system and DI container, this util also allows you to provide DI container mocks, which will be required for certain testing flows.

// component.test.ts
import { Connect } from '@genesislcap/foundation-comms';
import { ConnectMock } from '@genesislcap/foundation-comms/testing';
import { assert, createComponentSuite, Registration } from '@genesislcap/foundation-testing';
import { MyComponent } from './component';

* As we're using tag name in the Suite, we hold a reference to avoid tree shaking.

* Create mock
const connectMock = new ConnectMock();
connectMock.nextMetadata = {
NAME: 'foo',
TYPE: 'bar',

* Resister mock instance
const mocks = [Registration.instance(Connect, connectMock)];

const Suite = createComponentSuite<MyComponent>(
'my-component', // < or () => myComponent() if your component is composeable

Suite('Can be created in the DOM', async ({ element }) => {

Suite('Connect is mocked in the container', async ({ container }) => {
const serviceMock = container.get(Connect);
assert.instance(serviceMock, ConnectMock);

Suite('Attr changes update internals as expected', async ({ element }) => {
element.setAttribute('resource-name', 'ALL_USERS');
assert.match(element.optionsHash, /ALL_USERS/);
element.setAttribute('order-by', 'USERNAME');
assert.match(element.optionsHash, /USERNAME/);

Suite('Connect.getMetadata returns expected nextMetadata', async ({ container }) => {
const serviceMock = container.get(Connect) as ConnectMock;
* Assert base case
let serviceMeta = await serviceMock.getMetadata('someResource');[0].NAME, 'foo');
* Apply next and assert
const metadata = {
NAME: 'hello',
TYPE: 'world',
serviceMock.nextMetadata = {
serviceMeta = await serviceMock.getMetadata('someResource');
assert.equal(serviceMeta, {
// TODO: Trigger and cross check component reactions to underlying data changes

Testing E2E

The baseline.e2e.ts file uses playwright, and test cases will have access to the fixtures provided during set-up.

import { expect } from '@playwright/test';
import { test } from '@genesislcap/foundation-testing/e2e';

test('baseline test', async ({ page }) => {
await page.goto('');
const name = await page.innerText('.navbar__title');

We will be adding more details on E2E in future updates.