We have a set of contributor docs to guide you through your first PR, find good projects to contribute to, and learn about the code base, available on our docs site.
To build and run the server you must have the following installed (and running):
- Mac only: Homebrew for Mac (https://brew.sh/)
- Mac only: Docker for Mac (https://docs.docker.com/docker-for-mac/install/)
- Mac only: The latest version of bash
brew install bash - fswatch
brew install fswatch/apt install fswatch - PIP
brew install python/apt install python3-pip - live reload
pip3 install livereload
The app and its dependencies are all held within the container. While code is edited on your machine, the application is compiled and run inside of the container.
Ensure that docker:
- set to use 4 CPUs, 4.0 GiB of Memory, and 4.0 GiB of Swap (under the Advanced preferences tab).
Ignore the other tabs (for example you don't need to enable Kubernetes).
A local DNS server is needed to access the application via a .localhost TLD. The following is a quick start, adapted from this guide.
Install dnsmasq:
brew install dnsmasq / apt install dnsmasq
Follow brew's post-install instructions:
brew info dnsmasq
(probably sudo brew services start dnsmasq)
Add the following to (brew --prefix)/etc/dnsmasq.conf
address=/localhost/127.0.0.1
Restart dnsmasq:
sudo brew services restart dnsmasq / sudo /etc/init.d/dnsmasq restart
Configure OSX to use dnsmasq (not needed on linux):
sudo mkdir -p /etc/resolver
sudo tee /etc/resolver/localhost >/dev/null <<EOF
nameserver 127.0.0.1
EOF
Test it:
# Make sure you haven't broken your DNS.
ping -c 1 www.google.com
# Check that .localhost names work
dig testing.builtwithdark.localhost @127.0.0.1
- Run
scripts/builder --compile --watch --test - Wait until the terminal says "Finished initial compile" - this means the
build server is ready. The
builderscript will sit open, waiting for file changes in order to recompile - If you see "initial compile failed", it may be a memory issue. Ensure you have docker configured to provide 4GB or more of memory, then rerun the builder script. (Sometimes just rerunning will work, too).
- Open your browser to http://darklang.localhost:8000/a/dark/, username "dark", password "what"
- Edit code normally - on each save to your filesystem, the app will be rebuilt and the browser will reload as necessary
If you've gotten this far, you're now ready to contribute your first PR.
Unit tests run when you specify --test to scripts/builder. You can run them as a once off using:
scripts/runtests# clientscripts/run-backend-testsscripts/run-rust-tests
Integration tests:
scripts/run-in-docker ./integration-tests/run.sh
You can also run integration tests on your (host) machine, which gives you some debugging ability, and typically runs faster:
./integration-tests/run.sh
There are good debugging options for integration testing. See integration-tests/README.
scripts/run-in-docker bash
scripts/run-in-docker psql -d devdb
Config files are in config/. Simple rule: anything that runs inside the container must use a DARK_CONFIG value set in config/, and cannot use any other env var.
You can enable the FluidDebugger by mousing over the Gear in the left-sidebar. There is also "Enable debugger" which enables a legacy debugger that nobody uses and doesn't work well.
If you're using Chrome, enable Custom Formatters to see OCaml values in Chrome Dev Tools instead of their JS representation. From within Chrome Dev Tools, click "⠇", "Settings", "Preferences", "Enable Custom Formatters".