Introduces a multi-layered testing strategy for the libcosmic widget toolkit:
- Visual snapshot testing: Renders widgets via tiny-skia software renderer and
compares pixel output against reference PNGs. Generates diff images on failure.
Covers containers, dividers, text styles, progress bars, and layouts.
- Widget unit tests: Thorough behavioral tests for segmented button model
(selection, ordering, data storage, enable/disable, closable, indent),
calendar model (month navigation, year wrapping, date selection, grid layout),
spin button (clamping, increment/decrement, float support), and color picker.
- Property-based tests (proptest): Randomized input testing for spin button
bounds invariants, calendar first-day-of-week correctness, segmented model
length/clear/toggle invariants, and theme spacing monotonicity.
- Theme consistency tests: Validates all four theme variants (dark, light,
high-contrast dark/light) have valid spacing, corner radii ordering,
non-zero-alpha colors, visible text-on-background, and RON round-trip
serialization.
- Expanded inline tests: 16 new spin_button unit tests covering increment,
decrement, clamping, float types, and constructor value bounds.
- CI integration: New visual-tests job runs snapshot, theme, property, and
widget tests with artifact upload on failure for snapshot diffs.
https://claude.ai/code/session_01P3WLXMif9wmNXbWDo5FhRQ
