zireael-golden-fixtures

name	zireael-golden-fixtures
description	Maintain deterministic diff-output golden tests with byte-for-byte fixture comparison.
metadata	{"short-description":"Golden tests + fixtures"}

When to use

Use this skill when:

• implementing or changing diff renderer output
• changing cursor movement or SGR emission rules
• changing color degradation or attribute support
• adding new golden fixtures

Source of truth

• docs/GOLDEN_FIXTURE_FORMAT.md — fixture storage and comparison format
• docs/modules/TESTING_GOLDENS_FUZZ_INTEGRATION.md — test strategy
• docs/VERSION_PINS.md — pinned policies affecting output

Golden invariants (must follow)

• Goldens compare raw bytes byte-for-byte
• No normalization allowed for diff-output goldens
• Fixtures must pin:
  • plat_caps_t (color mode, attr support)
  • initial terminal state (zr_term_state_t)
  • Unicode width policy

Adding a new fixture

1. Create directory: tests/golden/fixtures/<fixture_id>/
2. Add:
   • case.txt (meta + prev/next grids)
   • expected.bin (canonical bytes)
   • expected.hex.txt (hex dump for review)
3. Ensure cols/rows match grid dimensions exactly
4. Use ~ as continuation marker for wide glyphs

Review checklist

• Fixtures are minimal (small grids)
• Each fixture targets one behavior
• Output changes are intentional with documented rationale
• Capability differences use separate fixtures, not normalization