alonf/mcppythondemo/mcp-stdio-parity-testing

MCP STDIO Parity Testing Skill

When to use

Use this pattern when a repo needs reviewer-grade validation for:

• a Python MCP stdio server
• a lecture/demo parity path against another reference implementation
• a client-side LLM workflow that should fail cleanly when credentials are missing

Pattern

1. Validate the server with the official SDK client

• start the server with StdioServerParameters
• run initialize
• assert tool discovery
• call the target tool on happy path
• call an invalid tool and confirm an error payload, not a crash

1. Add negative-path unit coverage around live system reads

• patch /proc readers
• require zero/fallback payloads instead of exceptions

1. Split client validation into two lanes

• fake-model/unit lane for deterministic tool-calling orchestration
• real CLI lane with credentials stripped so missing-config messaging is tested exactly as users see it

1. Make smoke output human-readable

• print the live server payload
• print the validated client failure message
• keep transport details out of the final QA summary

Files in this repo that follow the pattern

• tests/test_m1_smoke.py
• tests/test_system_info.py
• tests/test_client.py
• scripts/smoke_test.py