qa

Use whenever code that sends or receives AWS SQS messages needs tests: Standard vs FIFO semantics, visibility timeouts, dead-letter queues for poison messages and retention, using LocalStack, aws-sdk-client-mock for TypeScript or moto for Python.

Use before instrumenting a new feature, when spans have grown with no agreed shape, or after an incident where debugging stalled on missing attributes. Writes a trace spec per feature (root and child spans, key attributes per OpenTelemetry conventions) that drives code review and trace tests.

Use when a terminal UI (TUI) app needs tests that catch layout regressions. Captures rendered terminal frames as SVG or text snapshots and diffs them on each run: pytest-textual-snapshot for Textual, insta for Ratatui, teatest for Bubble Tea, ink-testing-library for Ink.

Use whenever pure C code for 8-bit MCUs, Cortex-M or embedded Linux needs unit tests with ThrowTheSwitch Unity (not the Unity game engine): TEST_ASSERT families, setUp and tearDown, RUN_TEST, the test runner generator, config defines and CI via Ceedling JUnit XML.

Use when a Varnish caching layer or VCL change needs tests: varnishtest VTC files with server, client and varnish blocks, grace and saint modes, PURGE handlers with ACLs, and surrogate-key invalidation with the xkey vmod.

Use when designing a color palette, reviewing a component's colors or auditing CSS for contrast: WCAG 2.2 text, large-text and non-text contrast ratios (4.5:1, 3:1) at AA and AAA, the measurement formula and bulk checks over design tokens.

Use after an accessibility scan across many pages (pa11y-ci, axe over a sitemap, Lighthouse batch) when the team needs a shareable conformance report. Groups violations by WCAG 2.2 success criterion and level, flags pages that were not scanned and writes a summary plus per-page detail.

Use when building or reviewing keyboard-only support or a modal, drawer or popover's focus handling: WCAG 2.2 keyboard access, no keyboard traps, shortcuts, focus order, visible and unobscured focus, with test scripts and the focus-trap pattern (focus on open, Escape, restore).

Use when a native Windows app (UWP, WPF, WinForms, Win32) must be driven from a Selenium-style client in C#, Java, Python, Ruby or JS: WinAppDriver directly or through the Appium 2 Windows driver, capabilities, AccessibilityId and Name locators, and Windows CI runners. C#-only: flaui-tests.