Instruction file imported from invector-tecnologia/tatui (.github/instructions/tests.instructions.md). Copyright stays with the author.

Testing — TaTUÍ

Structure

• Tests use Nim's unittest module and are aggregated in tests/all_tests.nim.
• Deterministic rendering assertions use TestBackend, which renders into an in-memory Buffer instead of a real TTY.

Golden snapshots

• Rendered output is asserted against golden files in tests/snapshots/.
• A snapshot is a plain-text render of a Buffer: one line per row, with a companion style map when styles are under test.
• Changing a golden file must be intentional; note it in the change description.

Layout truth-tables

• Layout tests are table-driven: (area, direction, constraints) -> expected rects.
• Cover interactions of Min/Max/Ratio/Fill and integer rounding on the cell grid.

Allocation & fuzz

• test_alloc_invariant.nim asserts getOccupiedMem() delta == 0 across steady-state ticks.
• fuzz/ansi_parser_smoke.nim feeds random/malformed byte streams to the event parser and asserts it never crashes.