Task 4.3 closes the loop on Chunk 4: the FastAPI lifespan now selects
fake vs real clients via IX_TEST_MODE (new AppConfig field), wires
/healthz probes to the live selfcheck() on OllamaClient / SuryaOCRClient,
and spawns the worker with a production Pipeline factory that builds
SetupStep -> OCRStep -> GenAIStep -> ReliabilityStep -> ResponseHandler
over the injected clients.
Factories:
- make_genai_client(cfg) -> FakeGenAIClient | OllamaClient
- make_ocr_client(cfg) -> FakeOCRClient | SuryaOCRClient (spec §6.2)
Probes run the async selfcheck on a fresh event loop in a short-lived
thread so they're safe to call from either sync callers or a live
FastAPI handler without stalling the request loop.
Drops the worker-loop spawn_worker_task stub — the app module owns the
production spawn directly.
Tests: +11 unit tests (5 factories + 6 app-wiring / probe adapter /
pipeline build). Full suite: 236 passed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds the two Protocol-based client contracts the pipeline steps depend on,
plus test-oriented fakes. Real engines (Surya, Ollama) land in Chunk 4.
- ix.ocr.client.OCRClient — runtime_checkable Protocol with async ocr().
- ix.genai.client.GenAIClient — runtime_checkable Protocol with async
invoke(); GenAIInvocationResult + GenAIUsage dataclasses carry the
parsed model, token usage, and model name.
- FakeOCRClient / FakeGenAIClient: return canned results; both expose a
raise_on_call hook for error-path tests.
8 unit tests across tests/unit/test_ocr_fake.py + test_genai_fake.py
confirm protocol conformance, canned-return behaviour, usage/model-name
defaults, and raise_on_call propagation.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
