# Smoke / screenshot test

The [`smoke`](../../.github/workflows/smoke.yml) workflow launches the real
Waybar binary inside a **headless sway** compositor (software-rendered, no GPU)
and checks three things:

1. **It starts and stays alive** — with real modules (`clock`, `cpu`, `memory`,
   `disk`) loaded, Waybar must not crash or log a fatal error.
   ([`modules-config.jsonc`](modules-config.jsonc))
2. **It renders** — a deterministic config ([`config.jsonc`](config.jsonc) +
   [`style.css`](style.css)) is captured with `grim`; the bar strip must not be
   blank.
3. **It looks right** — the screenshot is compared to `reference.png` with an 8%
   fuzz and an 800-pixel tolerance. Regressions fail the job, and the screenshot
   and diff are uploaded as artifacts.

## Updating the reference image

`reference.png` must be generated by the CI environment (local rendering differs
from Ubuntu's). To (re)bless it:

1. Push your change and open the run of the `smoke` workflow.
2. Download the `waybar-screenshot` artifact.
3. Commit its `bar.png` as `test/smoke/reference.png`.

Do this whenever an **intended** visual change makes the golden comparison fail.

## Run locally

On a machine with `sway`, `grim` and `waybar`:

```sh
./test/smoke/run.sh test/smoke/config.jsonc test/smoke/style.css /tmp/bar.png
```