diff --git a/Makefile b/Makefile
index 0189f821..d47e38a0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,7 @@
 .DEFAULT_GOAL := help
 
+JS_TEST_URL := http://localhost:8001/umap/static/umap/test/index.html
+
 .PHONY: install
 install: ## Install the dependencies
 	python3 -m pip install --upgrade pip
@@ -73,10 +75,21 @@ vendors:
 	npm run vendors
 installjs:
 	npm install
-testjsfx:
-	firefox umap/static/umap/test/index.html
+
 testjs: node_modules
-	@./node_modules/mocha-phantomjs/bin/mocha-phantomjs --view 1024x768 umap/static/umap/test/index.html
+	@{ \
+		trap 'kill $$PID; exit' INT; \
+		python -m http.server 8001 & \
+		PID=$$!; \
+		sleep 1; \
+		echo "Opening $(JS_TEST_URL)"; \
+		if command -v python -m webbrowser > /dev/null 2>&1; then \
+			python -m webbrowser "$(JS_TEST_URL)"; \
+		else \
+			echo "Please open $(JS_TEST_URL) in your web browser"; \
+		fi; \
+		wait $$PID; \
+	}
 tx_push:
 	tx push -s
 tx_pull:
diff --git a/docs/contributing.md b/docs/contributing.md
index c96991a8..e66baea0 100644
--- a/docs/contributing.md
+++ b/docs/contributing.md
@@ -29,19 +29,52 @@ To be sure to install all the dev dependencies, and have everything working loca
 make develop
 ```
 
+#### JavaScript
+
+For JavaScript, here is the tooling we use:
+
+- Format your code with [Prettier](https://prettier.io/)
+- Be sure to configure your editor to insert new lines at the end of files.
+
 ### Hack!
 
 You can now do your changes in a specific branch, and when you're ready you can open a pull-request for us to review.
 
-### Run tests
+### Running tests
 
 Multiple tests suites are in use in the project.
 
-| Test suite             | Location                  | Command                 |
-| ----------             | --------                  | -------                 |
-| Python unit tests      | `umap/tests/`  | `pytest . --ignore umap/tests/integration` |
-| Javascript unit tests  | `umap/static/test`        | `make testjs`|
-| Integration tests      | `umap/tests/integration`  | `pytest umap/tests/integration` |
+
+#### Python unit tests
+
+```bash
+pytest . --ignore umap/tests/integration
+```
+
+By default, the tests are run in parallel to reduce the time taken to run them. You can run them in serial mode by using the `-n1` option.
+
+If you only want to run one test, you can add `-k specific-test-name` to the command line.
+
+#### Integration tests
+
+```bash
+pytest umap/tests/integration
+```
+
+The tests are using [Playwright](https://playwright.dev), which spawns a headless browser and runs the tests on it.
+If the tests are failing, it might be useful to step trough the tests in the browser. This will let you go step by step with a debugger, so you can see what is happening on a real browser.
+
+```bash
+PWDEBUG=1 pytest --headed -n1 -k specific-test-name
+```
+
+#### JS tests
+
+```bash
+make testjs
+```
+
+These tests are located in `umap/static/test`, and we are currently using a mocha test runner.
 
 All the tests are run when you're creating a pull request, to avoid regressions.
 
diff --git a/docs/install.md b/docs/install.md
index 70b60cd6..77e36a27 100644
--- a/docs/install.md
+++ b/docs/install.md
@@ -168,4 +168,4 @@ pip install umap-project --upgrade
 umap migrate
 umap collectstatic
 umap compress
-```
\ No newline at end of file
+```
diff --git a/umap/models.py b/umap/models.py
index 4dfcf2ef..71f68144 100644
--- a/umap/models.py
+++ b/umap/models.py
@@ -16,7 +16,7 @@ from .managers import PublicManager
 # Did not find a clean way to do this in Django
 # - creating a Proxy model would mean replacing get_user_model by this proxy model
 #   in every template
-# - extending User model woulc mean a non trivial migration
+# - extending User model would mean a non trivial migration
 def display_name(self):
     return settings.USER_DISPLAY_NAME.format(**self.__dict__)