nim-testing

name	nim-testing
description	Use when writing or updating TaTUÍ tests: TestBackend usage, golden snapshot format, layout truth-tables, the allocation invariant test, or ANSI parser fuzzing. Triggers: test, snapshot, golden, TestBackend, unittest, truth-table, allocation test, fuzz.

Testing TaTUÍ

Harness

• Nim unittest; every suite is imported by tests/all_tests.nim (run via nimble test).
• TestBackend renders into an in-memory Buffer — assert on cells/rows without a real TTY.

Golden snapshots

• Store expected renders in tests/snapshots/<name>.txt: one line per buffer row.
• When styles matter, add <name>.style.txt mapping cells to a style legend.
• Update goldens deliberately; call out the change in the PR/description.

Layout truth-tables

check split(area, Vertical, @[length(3), fill(1)]) == @[rect(...), rect(...)]

Cover Min/Max/Ratio/Fill interactions and integer-rounding boundaries.

Allocation invariant

test_alloc_invariant.nim: run N steady-state ticks, assert getOccupiedMem() delta == 0.

Fuzz smoke

fuzz/ansi_parser_smoke.nim: feed random/truncated escape byte streams; assert no crash and total consumption of input.