Development

Gates

nix develop (or direnv) enters the dev shell, and just lists the recipes. just gates runs every gate CI runs:

Recipe	What it does
just fmt-check	Formatting
just check	vet, lint, no-fused, test, build
just race	The test suite under the race detector
just gpu	The GPU tests on lavapipe
just headless	The capture and virtual input tests against a private headless sway

just gpu-host runs every GPU path on the host's own GPU, under the validation layer. nix fmt formats the nix files with alejandra.

just docker <recipe> (default gates) runs a recipe in a container that sees the dev shell's store paths, the checkout, the GPUs' render and NVIDIA device nodes and the host's drivers, but no display socket, session bus or runtime dir of the desktop session, with memory capped.

Same input, same output

Rendering, typesetting, animation and styling give the same bits on every architecture, so one golden holds on all of them. Floating point needs two rules for that, each with a gate:

• The Go spec lets the compiler fuse x*y + z into an FMA, which skips rounding the product; arm64 does, amd64 does not. Write float64(x*y) + z where a product, or a division by a constant power of two, reaches an addition or a subtraction, across statements too. just no-fused compiles for arm64 and fails on any FMA instruction.
• Call gomath for trigonometry, exponentials, logarithms, Pow, Cbrt and Hypot, since math's own results differ between architectures. The linter refuses math's versions outside tests.

CI

.github/workflows/ci.yml runs just gates in the dev shell. .github/workflows/security.yml runs CodeQL (Go and GitHub Actions), Grype and govulncheck, uploading findings to code scanning, and dependency review gates pull requests against a licence allow-list. Dependabot keeps the module and the workflows current. Every action is pinned to a commit.

Test support

These packages are for tests, here and in other family members.

Package	What it does
golden	Compares rendered pixels against committed PNG snapshots, exact by default. A missing golden fails the test, and References from another renderer compare within a Tolerance
gputest	Picks the Vulkan driver the GPU tests run on from LYS_TEST_GPU: lavapipe for Mesa's CPU driver, any other value for the host's device, and unset runs where a device is found and skips elsewhere
wltest	A private runtime dir and a loopback display for wire-level tests, and a client that puts solid-colored surfaces on the headless compositor for capture tests to find
pipewire/pwtest	A private PipeWire daemon, and libpipewire consumers as the reference a producer is checked by
dbustest	Private dbus-daemons, configured from a file the helper writes, so a test needs only dbus-daemon on PATH
sockdir	A directory short enough to hold Unix sockets, since sun_path holds 108 bytes

History

The packages moved here from lys-ui and lys-shell with their history. Issue numbers in that history name their repository (stubbedev/lys-ui#N, stubbedev/lys-shell#N).