+### Client and server side
+
+The API will listen on `localhost:9000` and the frontend on `localhost:3000`.
+File changes are automatically recompiled, injected in the web browser (no need to refresh manually)
+and the web server is automatically restarted.
+
+```
+$ npm run dev
+```
+
+### RTL layout
+
+To test RTL layout using `ar` locale:
+
+```
+$ npm run dev -- --ar-locale
+```
+
+### Testing
+
+Your code contributions must pass the tests before they can be merged. Tests ensure most of the application behaves
+as expected and respect the syntax conventions. They will run upon PR submission as part of our CI, but running them beforehand yourself will get you faster feedback and save CI runner time for others.
+
+PeerTube mainly features backend and plugin tests, found in `server/tests`.
+
+#### Unit tests
+
+Create a PostgreSQL user **with the same name as your username** in order to avoid using the *postgres* user.
+
+Then, we can create the databases (if they don't already exist):
+
+```
+$ sudo -u postgres createuser you_username --createdb --superuser
+$ npm run clean:server:test
+```
+
+Build the application and run the unit/integration tests:
+
+```
+$ npm run build -- --light
+$ npm test
+```
+
+If you just want to run 1 test (which is what you want to debug a specific test rapidly):
+
+```
+$ TS_NODE_FILES=true npm run mocha -- --exit -r ts-node/register -r tsconfig-paths/register --bail server/tests/api/videos/single-server.ts
+```
+
+While testing, you might want to display a server's logs: