HIGH: All Python integration tests fail - missing internal auth header in test clients

[Senthil455]

Summary

All Python integration tests fail because their API endpoints require the x-internal-auth header, but the test clients never set it. Every non-health endpoint returns 401.

Affected Files

• services/analytics-python-service/test_main.py:25-30
• services/ai-copilot-service/test_main.py:26-36
• services/ats-service/test_main.py:29-38

Root Cause

All Python services have an internal_auth_middleware that returns 401 for any request (except /health) missing the x-internal-auth header:

@app.middleware("http")
async def internal_auth_middleware(request, call_next):
    if request.url.path == "/health":
        return await call_next(request)
    
    auth_header = request.headers.get("x-internal-auth")
    if not auth_header:
        return JSONResponse(status_code=401, content={"error": "Missing internal authentication"})

But the tests use TestClient(app) without setting this header:

response = client.get("/analytics/performance")  # No x-internal-auth header -> 401

Additionally, the employee service test cannot import because it uses os.environ["MONGO_USER"] (bracket access) at module level, which raises KeyError if the env var is not set.

Impact

• ALL test assertions except test_health_check fail with 401
• CI reports passing but tests never actually run
• Zero test coverage for actual business logic
• False confidence in test suite

Fix Required

1. Set the x-internal-auth header in all test clients:

def client():
    with TestClient(app) as c:
        yield c  # But how to add header to every request?

For TestClient, use a header override or disable the middleware in tests:

# Option 1: Pass the header in every request
response = client.get("/endpoint", headers={"x-internal-auth": "test-key"})

# Option 2: Override the middleware dependency
app.dependency_overrides[verify_internal_auth] = lambda: True

2. For employee service: Use os.environ.get() instead of os.environ[], or set env vars before import.

[Senthil455]

Fixed in PR #122 - Added _make_internal_token()+x-internal-auth header to test clients; fixed 4 os.environ[...] bracket accesses