`pfg fastapi smoke`

Capabilities

pfg fastapi smoke introspects a FastAPI app, generates deterministic request/response payloads, and writes a pytest module with one smoke test per route. Each test makes a live request using TestClient, asserts a 2xx response, and validates the payload with the same fixturegen generator the rest of the CLI uses.

Typical use cases

Guard every route with a deterministic smoke test without writing repetitive code.
Generate a baseline test suite for new services before writing focused unit tests.
Share seed-locked smoke suites across teams so failures are easy to debug.

Inputs & outputs

Target: FastAPI import path (module:attr, for example app.main:app). Required.
Output: --out (default tests/test_fastapi_smoke.py). The command overwrites the file with the freshly generated suite.

Flag reference

--out/-o: pytest module destination.
--seed: override the deterministic seed embedded in the generated suite. When omitted, tests call fixturegen with the default seed from config.
--dependency-override original=override: repeatable option that injects FastAPI dependency overrides (resolves dotted or colon-separated paths). Essential for bypassing authentication, rate limiters, etc.

Example workflows

Generate smoke tests with dependency stubs

pfg fastapi smoke app.main:app \

  --out tests/test_fastapi_smoke.py \

  --seed 11 \

  --dependency-override "app.dependencies.get_current_user=fakes.allow_all"

Writes one pytest function per route, overriding `get_current_user` so auth checks pass.

Sample output

Smoke tests written to tests/test_fastapi_smoke.py

Routes covered: 12

Dependency overrides: ['app.dependencies.get_current_user=fakes.allow_all']

Excerpt from generated tests/test_fastapi_smoke.py

def test_get_users_returns_200(smoke_client):

    payload = generate_payload("GET /users")

    response = smoke_client.get("/users", params=payload.query, headers=payload.headers)

    assert response.status_code == 200

    assert response.json() == payload.expected

Separate smoke suites per router

pfg fastapi smoke app.api.users:router \

  --out tests/smoke/test_users_api.py \

  --seed 5 \

  --dependency-override "app.dependencies.get_db=fakes.memory_db"

Generates a focused smoke module for the users router while overriding the DB dependency with an in-memory stub.

Operational notes

Requires the fastapi extra (pip install pydantic-fixturegen[fastapi]).
Routes are grouped by HTTP method; each smoke test exercises validation via fixturegen so payloads stay reproducible.
Custom overrides are evaluated via import, so ensure the override target is importable (module path or pkg.module:attr).
Exit codes follow Typer defaults; missing app attributes trigger DiscoveryError with helpful hints.

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pfg fastapi smoke