Files
honeyDueKMP/docs/screenshot-tests.md
Trey T 40d2607da8 Suite6 + P8: Comprehensive task tests + Roborazzi scaffolding
Suite6_ComprehensiveTaskTests ports iOS tests not covered by Suite5/10
(priority/frequency picker variants, custom intervals, completion history,
edge cases).

Roborazzi screenshot-regression scaffolding in place but gated with @Ignore
until pipeline is wired — first `recordRoborazziDebug` run needs manual
golden-image review. See docs/screenshot-tests.md for enablement steps.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-18 17:39:39 -05:00

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# Roborazzi screenshot regression tests (P8)
Roborazzi is a screenshot-diff testing tool purpose-built for Jetpack /
Compose Multiplatform. It runs on the Robolectric-backed JVM unit-test
classpath, so no emulator or physical device is required — perfect for
CI and for catching UI regressions on every PR.
## Why screenshot tests?
Unit tests assert logic; instrumentation tests assert user-visible
behaviour. Neither reliably catches *design* regressions: a colour drift
in `Theme.kt`, a typography scale change, an accidental padding edit.
Screenshot tests close that gap by diffing pixel output against a
committed golden set.
## What we cover
The initial matrix (see `composeApp/src/androidUnitTest/.../ScreenshotTests.kt`)
is intentionally conservative:
| Surface | Themes | Modes | Total |
|---|---|---|---|
| Login | Default · Ocean · Midnight | light · dark | 6 |
| Tasks | Default · Ocean · Midnight | light · dark | 6 |
| Residences | Default · Ocean · Midnight | light · dark | 6 |
| Profile | Default · Ocean · Midnight | light · dark | 6 |
| Theme palette | Default · Ocean · Midnight | light · dark | 6 |
| Complete task | Default · Ocean · Midnight | light · dark | 6 |
| **Total** | | | **36** |
The full 11-theme matrix (132+ images) is deliberately deferred — the
cost of reviewer approval on every image outweighs the marginal cover.
Each test renders a *showcase* composable (pure Material3 primitives)
rather than the full production screen. That keeps Roborazzi hermetic:
no DataManager, no Ktor client, no ViewModel. A regression in
`Theme.kt`'s colour scheme will still surface because the showcases
consume every colour slot the real screens use.
## Commands
```bash
# Record a fresh golden set (do this on first setup and after intentional UI changes)
./gradlew :composeApp:recordRoborazziDebug
# Verify current UI matches the golden set (fails the build on drift)
./gradlew :composeApp:verifyRoborazziDebug
# Generate side-by-side diff images (useful for review)
./gradlew :composeApp:compareRoborazziDebug
```
Output lands under `composeApp/build/outputs/roborazzi/`.
## Golden-image workflow
Roborazzi goldens are *not* auto-committed. The workflow is:
1. Developer changes a composable (intentionally or otherwise).
2. CI runs `verifyRoborazziDebug` and fails on any drift.
3. Developer inspects the diff locally via `compareRoborazziDebug` or
from the CI artifact.
4. If the drift is intentional, regenerate via
`recordRoborazziDebug` and commit the new PNGs inside the PR so the
reviewer explicitly sign-offs on each image change.
5. If the drift is a regression, fix the composable and re-run.
**Reviewer checklist:** every committed `.png` under the roborazzi output
dir is an intentional design decision. Scrutinise as carefully as you
would scrutinise the code change it accompanies.
## Adding a new screenshot test
```kotlin
@Test
fun mySurface_default_light() = runScreen(
name = "my_surface_default_light",
theme = AppThemes.Default,
darkTheme = false,
) {
MySurfaceShowcase()
}
```
Add the corresponding dark-mode and other-theme variants, then run
`recordRoborazziDebug` to generate the initial PNGs.
## Known limitations
- Roborazzi requires `@GraphicsMode(Mode.NATIVE)` — the Robolectric
version in this repo (4.14.1) supports it.
- The test runner uses a fixed device qualifier (`w360dp-h800dp-mdpi`).
If you change this, every golden must be regenerated.
- `captureRoboImage` only captures the composable tree, not window
chrome (status bar, navigation bar). That's intentional — chrome
is owned by the OS, not our design system.
## References
- Upstream: https://github.com/takahirom/roborazzi
- Matrix rationale: see commit message on `P8: Roborazzi screenshot
regression test scaffolding`.