Reviewing Python Architecture

1. Read /testing for methodology (5 stages, 5 factors, 7 exceptions)
2. Identify violations of testing principles and parent PDR constraints
3. Output APPROVED or REJECTED with specific violations
4. Show correct approach with code examples

Level definitions (from Stage 2 Five Factors):

• Level 1: Pure computation, file I/O with temp dirs, standard dev tools (git, curl)
  • Test directly, no doubles needed
• Level 2: Real dependencies via harnesses (Docker, databases, project-specific binaries)
  • Use real systems, not fakes
• Level 3: Real credentials, external services, browsers
  • Full real-world workflows

Critical rules (from Five Factors):

• Standard dev tools (git, cat, grep, curl) are Level 1
• Project-specific tools (Docker, PostgreSQL, Hugo) are Level 2
• SaaS services (Trakt, GitHub API, Stripe, Auth0) jump from Level 1 → Level 3 (no Level 2)
• Network dependencies and external services are Level 3

Mocking prohibition (Cardinal Rule):

• NO mocking. Ever. - /testing cardinal rule
• NO unittest.mock.patch for external services
• NO respx.mock for internet APIs
• Use dependency injection with Protocol interfaces instead
• Test doubles (stubs, spies, fakes) only when exception case applies

Reality principle:

• "Reality is the oracle" - tests must verify behavior against real systems
• A fake proves your code works with your imagination, not the real system

Test doubles require exception case (Stage 5):

• Only 7 legitimate exceptions for test doubles
• Each use must document which exception applies
• No exception = no doubles, test at Level 2

# ARCHITECTURE REVIEW

**Decision:** [APPROVED | REJECTED]

---

## Violations

### {Violation name}

**Where:** Lines {X-Y}
**Principle violated:** /testing {section name}
**Why this fails:** {Direct explanation}

**Correct approach:**

```{language}
{Show what the architecture should be}
```

{Repeat for each violation}

Required Changes

{Concise list of what must change}

References

• /testing: {section name} (principle violated)
• /standardizing-python-testing: {section if applicable}

{If REJECTED: "Revise and resubmit"} {If APPROVED: "Architecture meets standards"}

</output_format>

<review_guidelines>

**Don't:**

- Reference specific line numbers (they change)
- Provide grep commands
- Explain multiple times
- Count statistics

**Do:**

- Reference `/testing` section names (e.g., "Stage 5 Exception 1", "Cardinal Rule")
- Show correct architecture with code examples
- Be direct about violations
- Reference `/standardizing-python-testing` for Python-specific patterns

</review_guidelines>

<example_review>

```markdown
# ARCHITECTURE REVIEW

**Decision:** REJECTED

---

## Violations

### Level 2 Assigned to SaaS Service

**Where:** Lines 132-133
**Principle violated:** /testing Stage 2 Factor 2

Trakt.tv is a SaaS service that cannot run locally. Per /testing Five Factors:
- SaaS services have no Level 2 - jump from Level 1 to Level 3

**Correct approach:**

```markdown
| List operations | 1 | DI with TraktListProvider protocol |
| List operations | 3 | Real Trakt API with test account |

Mocking External Services

Where: Lines 132, 133, 145 Principle violated: /testing Cardinal Rule

Testing Strategy says "Mock at the PyTrakt API boundary" - this violates the NO MOCKING principle.

Correct approach:

Use dependency injection per /standardizing-python-testing:

class TraktListProvider(Protocol):
    def __call__(self, list_name: str, username: str) -> Any | None: ...


# Level 1: Inject fake implementation (Exception 1: Failure modes)
# Level 3: Use real PyTrakt

Required Changes

1. Remove all Level 2 assignments for SaaS operations
2. Remove "Mock at boundary" language
3. Add DI protocol definitions per /standardizing-python-testing
4. Document which exception case justifies any test doubles

References

• /testing: Cardinal Rule (no mocking)
• /testing: Stage 2 Factor 2 (dependency levels)
• /testing: Stage 5 (exception cases for test doubles)
• /standardizing-python-testing: Protocol patterns

Revise and resubmit.

</example_review>

<success_criteria>
Review is complete when:

- [ ] Checked for mocking violations (Cardinal Rule)
- [ ] Verified level assignments match `/testing` Five Factors
- [ ] Checked test double usage has documented exception case
- [ ] Output follows format with section references (not line numbers)
- [ ] Correct approach shown with code examples

</success_criteria>