hedgedoc/docs/content/dev/setup/frontend.md

Setting up the frontend

Follow the preparation instructions in getting started

Development mode

Mocked Backend Mode

To start the development mode run yarn run dev. If not configured otherwise the development mode will run in mock-mode which emulates a HedgeDoc backend. The app should run now and be available under http://localhost:3001 in your browser. In development mode the app will autoload changes you make to the code.

With local backend

To start the development mode with an actual HedgeDoc backend use yarn run dev:with-local-backend instead. This task will automatically set HD_EDITOR_BASE_URL to http://localhost:8080.

Performance

The development mode compiles everything on demand. So the first time you open a page in the browser it may take some time.

Production mode

Use yarn build to build the app in production mode and save it into the .next folder. The production build is minimized and optimized for best performance. Don't edit the generated files in the .next folder by hand!

You can run the production build using the built-in server with yarn start. You MUST provide the environment variable HD_EDITOR_BASE_URL with protocol, domain and (if needed) subdirectory path ( e.g. http://localhost:3001/) so the app knows under which URL the frontend is available in the browser.

Production mock build

It is also possible to create a production build that uses the emulated backend by using yarn build:mock. This is usually not needed except for demonstration purposes like https://hedgedoc.dev.

Environment Variables

The following environment variables are recognized by the frontend process.

Name	Possible Values	Description
HD_EDITOR_BASE_URL	Any URL with protocol, domain and optionally directory and port. Must end with a trailing slash. (e.g. http://localhost:3001/)	The URL under which the frontend is expected. Setting this is mandatory so the server side rendering can generate assets URLs. You only need to set this yourself if you use the production mode.
HD_RENDERER_BASE_URL	Same as HD_EDITOR_BASE_URL	You can provide this variable if the renderer should use another domain than the editor. This is recommended for security reasons but not mandatory. This variable is optional and will fallback to HD_EDITOR_BASE_URL
NEXT_PUBLIC_USE_MOCK_API	true, false	Will activate the mocked backend
NEXT_PUBLIC_TEST_MODE	true, false	Will activate additional HTML attributes that are used to identify elements for test suits.

Variables that start with NEXT_PUBLIC_ will be compiled into the build. You can't change them at after compilation. You shouldn't need to set them yourself. Use the designated npm tasks instead.

UI Test

Curious about the new look and feel? We provide a demo of the new UI on hedgedoc.dev. This version uses mocked data and has no data persistence.

The UI test is hosted by netlify. Please check their privacy policy as well as ours.

Running Tests

Unit

Unit testing is done via jest.

1. Run yarn test

End2End

We use cypress for e2e tests.

1. Start the frontend with yarn dev:test (or use a test build using yarn build:test which you can start using yarn start). The usage of :test is mandatory!
2. Run yarn cy:open to open the cypress test loader
3. Choose your browser and start a test suite

To run all tests in a headless browser use yarn cy:run:chrome or yarn cy:run:firefox

Bundle analysis

You can inspect the generated production-bundle files to look for optimization issues.

1. run yarn analyze. This will overwrite any existing builds!
2. Open the generated .next/server/analyze/server.html in your favourite browser