Testing — ITISYOU OS

Test pyramid

1. Host unit tests (cargo test -p kernel-core -p image-builder -p qemu-runner) — pure logic: stage/marker contract, SHA-256 vectors, and (as subsystems land) memory-map normalization, allocator logic, path handling, shell parsing. Fast, deterministic, no QEMU.
2. QEMU boot smoke — boots the interactive kernel (BIOS and UEFI), asserts stages B010/B020/B030 appear within the timeout.
3. QEMU selftest suite — boots itisyou-kernel-selftest, which runs in-kernel checks, emits [ITISYOU:TEST] events and a [ITISYOU:SELFTEST] pass=N fail=M summary, then exits QEMU through isa-debug-exit. The harness requires: all expected stages, fail=0, pass>0, and QEMU exit code 33. A hang, panic, or missing summary can never pass.
4. Userspace suite (V0.2, inside the selftest kernel + shell leg): Ring 3 execution of /bin/init with the full syscall ABI (its RING3-* output lines are --required by the harness), malformed-ELF and W^X rejection fixtures, #GP/#PF containment programs, kernel-alive and reload-after-teardown checks.
5. Negative cases (grown alongside subsystems): intentional panic, allocator exhaustion, malformed inputs, timeout classification.

Failure classification (tools/qemu-runner)

Outcome	Meaning
success	expected markers + clean exit (selftest: exit 33, fail=0)
selftest-failed	in-kernel test failure (or exit 35)
panic	[ITISYOU:PANIC] observed
timeout	deadline exceeded; QEMU killed; serial tail preserved
missing-markers	exited without required stage/summary markers
launch-failure	QEMU process could not start
unexpected-exit	exit status outside the contract (e.g. reset loop)

Evidence per run: artifacts/qemu/<label>.serial.log + <label>.result.json (outcome, exit code, stages seen/missing, test events, duration, full command line).

Commands

scripts\test.ps1     # unit tests + 4-way QEMU matrix
scripts\verify.ps1   # canonical full gate (adds fmt, clippy, doctor, secret scan, website)

Rules

• No skipped/disabled tests to obtain green status; a bug fix lands with a regression test that demonstrates the failure mode (plan §12.4).
• A test “passing” is only claimed from an actual run’s evidence, never from the existence of test code.