MOD.UK Frontend guidance site

This repo contains the source code for the MOD.UK Frontend guidance website.

Development

The library uses Eleventy, Sass, ESLint, Stylelint, dprint and commitlint. Git hooks (via Husky and lint-staged) are used for enforcing linting and formatting rules.

The unit test suite uses Vitest and Testing Library.

The end-to-end test suite uses Playwright. Tests are run across a variety of browsers and configurations against a local web server that serves examples of components. This includes accessibility checks using axe and visual regression tests.

Local development requires Node.js 16 or 18 and npm 8 or newer.

Setting up your development environment

1. Clone the repository via SSH:

   git clone git@github.com:defencedigital/moduk-frontend-guidance-site.git
   cd moduk-frontend-guidance-site

   If you haven’t set up an SSH key for GitHub, you can clone via HTTPS instead:

   git clone https://github.com/defencedigital/moduk-frontend-guidance-site.git
   cd moduk-frontend-guidance-site

2. Install dependencies:

   npm install

3. Install Playwright browsers and system dependencies:

   npm run playwright-install

4. Install Podman using the instructions for your platform.

   Podman is required only for running visual regression tests.

5. Ensure jq is installed. On macOS it can be installed using Homebrew:

   brew install jq

   jq is required only for running visual regression tests.

Commands

Start the server

npm start

Lint all files

npm run lint

Reformat all files

npm run format

Run all unit tests

npm test

Run end-to-end tests

npm run test:e2e

This runs end-to-end tests using Playwright for all configured browser configurations. The Eleventy dev server is started automatically, and so does not need to be started separately.

Run specific files using a regex

npm run test:e2e <regex>

You can also use test.only or test.desribe.only within a test file to run only that test (and any other tests using .only).

Run tests with tracing

npm run test:e2e:trace

Playwright traces record failed tests for debugging later, or on a different machine.

You can also debug tests using VS code, or by using the built-in inspector debugger.

Run visual regression tests in a container

Visual regression tests run in a container, using Podman, to ensure screenshots are taken in a consistent environment.

To run the visual regression tests:

npm run test:visual

This will also generate any missing screenshots.

Update visual regression snapshots

To update any screenshots that have changed:

npm run test:visual:refresh

Delete all visual regression snapshots

To delete all existing screenshots:

npm run test:visual:clean

This can be useful after renaming or deleting visual regression tests or component examples.

Build the static site

npm run build

The built site is output to the dist directory.

Build and run the container image

podman build --tag moduk-frontend-guidance-site .
podman run --rm -p 8080:8080 -it moduk-frontend-guidance-site

The server will then be available at http://localhost:8080.

Configuration

The BASE_URL environment variable can be set at build time to override the base URL of Open Graph images specified in <meta> tags. If not set, it defaults to using the images on the production site.

The NO_INDEX environment variable can be set at build time to add a noindex <meta> tag to all pages.

Acknowledgements

Some styles and markup are based on the GOV.UK Design System website.