jest-environment-hops

Please see the main Hops Readme for general information and a Getting Started Guide.

This package is part of Hops's internal tooling. Hence, it doesn't provide an API contract. Breaking changes may be introduced even with patch releases. Use at your own risk.

Installation

npm install --save-dev jest-environment-hops

Usage

Add jest-environment-hops as testEnvironment to your Jest config. This can for example be done by adding it to your package.json.

{
  "jest": {
    "testEnvironment": "jest-environment-hops"
  }
}

jest-environment-hops launches a Puppeteer instance during the setup-phase by default. Check the API part of this document, to learn how to interact with the instance.

To disable Puppeteer for a test, add the following code comment to the top of the test file:

/**
 * @jest-hops-puppeteer off
 */

API

The API & certain values are exposed globally in the Jest environment, so there's no need to import anything.

cwd: string

jest-environment-hops creates a temporary folder, in which the test runs. cwd holds the absolute path of that folder.

browser: Puppeteer.Browser | undefined

The Puppeteer instance, jest-environment-hops launches, is exposed via the global browser-variable.

In case Puppetteer is disabled via the code pragma @jest-hops-puppeteer off, the browser-variable's value is undefined.

HopsCLI.build: (env?: NodeJS.ProcessEnv, ...cliArgs: string[]): Promise<{ stdout: string, stderr: string, error?: Error }>

Builds the local Hops app into a temporary folder.

const { stderr, error } = await HopsCLI.build('-p');

expect(stderr).toBe('');
expect(error).not.toBeDefined();

HopsCLI.start: (env?: NodeJS.ProcessEnv, ...cliArgs: string[]): { getUrl: () => Promise<string>, stopServer: () => Promise<void> }

Starts the local Hops app, so it's possible to visit it with Puppeteer.

const { getUrl, stopServer } = HopsCLI.start(
  { NODE_ENV: 'testing' },
  '--fast-dev'
);
const url = await getUrl();

// visit URL...

// Stop server explicitly
await stopServer();

stopServer is exposed for special needs. jest-environment-hops takes care of stopping the Hops server, when all tests are done.

createPage(): () => Promise<object>

Convenience function for creating a new Puppeteer.Page-instance, which resolves to an object, that holds the page-instance and three helper functions.

const { page, getProperty, getInnerText, getElementByText } =
  await createPage();
await page.goto('http://localhost:8080/');

const headingClass = await getProperty('className', '.heading');
const headingText = await getInnerText('.heading');
const button = await getElementByText('Submit');

getProperty: (property: string, selector: string): Promise<string | null>

Returned by createPage. Take a look at createPage() to see a usage example.

getInnerText: (selector: string): Promise<string | null>

Returned by createPage. Take a look at createPage() to see a usage example.

getElementByText: (text: string): Promise<Puppeteer.ElementHandle>

Returned by createPage. Take a look at createPage() to see a usage example.

Throws an error, when no element has been found.