# Feature Specification: PostgreSQL Integration Test Infrastructure

**Feature Branch**: `008-postgres-integration-tests`
**Created**: 2026-05-06
**Status**: Draft

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## Overview

Integration tests currently permit any SQLAlchemy-compatible database URL, including SQLite. This allowed a real production bug (incorrect `HAVING` without `GROUP BY`) to ship undetected because SQLite's permissive dialect did not reject it. The project constitution (§2.5, §5.2 v1.3.0) now explicitly mandates PostgreSQL for integration tests. This feature enforces that mandate with infrastructure and guardrails.

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## User Scenarios & Testing

### User Story 1 — Integration tests are enforced to run against PostgreSQL (Priority: P1)

A developer running `pytest` against a non-PostgreSQL database URL receives an immediate, descriptive failure before any test runs.

**Why this priority**: Directly addresses the production bug that prompted this feature. Without this, the constitution mandate has no teeth.

**Independent Test**: Set `TEST_DATABASE_URL=sqlite+aiosqlite:///test.db` and run `pytest api/tests/integration/`. Confirm pytest exits immediately with a message identifying the dialect problem and naming the required scheme.

**Acceptance Scenarios**:

1. **Given** `TEST_DATABASE_URL` is set to a SQLite URL, **When** `pytest api/tests/integration/` is invoked, **Then** pytest exits before collecting any test with an error: `Integration tests require postgresql+asyncpg://`.
2. **Given** `DATABASE_URL` is unset and `TEST_DATABASE_URL` is unset, **When** pytest is invoked, **Then** pytest exits with a clear message about the missing database URL.
3. **Given** `TEST_DATABASE_URL` is a valid `postgresql+asyncpg://` URL, **When** pytest is invoked, **Then** tests collect and run normally.

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### User Story 2 — One-command integration test run against isolated services (Priority: P1)

A developer can run the entire integration test suite against dedicated, isolated PostgreSQL and MinIO instances with a single command.

**Why this priority**: Without this, the PostgreSQL requirement is mandated but impractical — developers have no easy way to satisfy it.

**Independent Test**: From the repo root with Docker available, run `docker compose -f docker-compose.test.yml run --rm api-test`. Confirm all integration tests pass, test containers start and stop cleanly, and dev database/bucket are untouched.

**Acceptance Scenarios**:

1. **Given** Docker is running and dev services are stopped, **When** the test command is run, **Then** isolated `postgres-test` and `minio-test` services start, all tests run against them, and the command exits with pytest's return code.
2. **Given** dev services are running on their normal ports, **When** the test command is run, **Then** test services use different ports (5433, 9002/9003) and do not interfere with the dev stack.
3. **Given** any test data is written during the run, **When** the test run completes, **Then** all test schema is dropped (conftest teardown is unchanged).

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### User Story 3 — Test infrastructure is documented (Priority: P2)

A developer new to the project can understand how to run unit tests vs integration tests without reading the source code.

**Independent Test**: Read `.env.test.example` and `Makefile`. Confirm all required environment variables are documented and `make test-unit` / `make test-integration` targets are present.

**Acceptance Scenarios**:

1. **Given** a fresh clone, **When** the developer reads `.env.test.example`, **Then** they see every variable needed to run integration tests outside Docker, with example values.
2. **Given** the Makefile, **When** the developer runs `make test-unit`, **Then** the pytest unit suite runs without requiring Docker.
3. **Given** the Makefile, **When** the developer runs `make test-integration`, **Then** the Docker Compose test command runs.

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### Edge Cases

- What if `TEST_DATABASE_URL` is set but malformed? — The guard should still catch a non-PostgreSQL scheme; asyncpg will raise its own error for a malformed URL.
- What if Docker is not available? — `make test-integration` fails at the Docker level with Docker's own error; the Makefile does not need to guard for this.
- What if the test PostgreSQL port (5433) is already in use? — Standard Docker port conflict error; no special handling needed.

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## Requirements

### Functional Requirements

- **FR-001**: `conftest.py` MUST assert the resolved database URL starts with `postgresql+asyncpg://` and call `pytest.exit()` with a descriptive message before any test collects.
- **FR-002**: A `docker-compose.test.yml` MUST define isolated `postgres-test` (port 5433) and `minio-test` (ports 9002/9003) services and an `api-test` runner service.
- **FR-003**: The `api-test` service MUST set `TEST_DATABASE_URL` pointing to `postgres-test` and all S3 env vars pointing to `minio-test`.
- **FR-004**: A `.env.test.example` MUST document all environment variables required to run integration tests outside Docker.
- **FR-005**: A `Makefile` MUST provide `test-unit` and `test-integration` targets.

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## Success Criteria

- **SC-001**: Running `pytest api/tests/integration/` with a SQLite URL exits in under 2 seconds with a clear error message — no tests run.
- **SC-002**: `docker compose -f docker-compose.test.yml run --rm api-test` completes successfully with all integration tests passing.
- **SC-003**: Dev services (postgres on 5432, minio on 9000) are unaffected when the test command runs.

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## Assumptions

- Docker Compose v2 (`docker compose`) is available in the developer environment.
- The existing `conftest.py` `engine` fixture (session-scoped `create_all` / `drop_all`) continues to handle schema lifecycle; no per-test transaction rollback mechanism is introduced.
- CI/CD pipeline configuration is out of scope for this feature.
