René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Test foundations (safety nets)","articleBody":"The safety net the core reworks rely on: pin today's behaviour so nothing can silently break it, and give every other ticket a way to write tests against the modern path. Zero dependencies — anyone can start today.\n\n## What's in it\n\n- Legacy wire-protection golden tests: pin the 2025 stateful and `stateless_http=True` paths byte-for-byte (session lifecycle, GET stream, resumability, the literal HTTP 400 error bodies the current transport returns, and the behaviour when no `MCP-Protocol-Version` header is sent), plus negative checks that no 2026 vocabulary leaks onto a 2025 wire.\n- In-memory / DirectDispatcher 2026 parity so other tickets can write end-to-end tests without HTTP.\n- Add the modern sessionless path as a `tests/interaction` connect-fixture leg, so every existing transport-agnostic test re-proves over the 2026 wire mode.\n- Optional: a public-API snapshot test (so accidental surface breaks are loud).\n\n## Conformance\n\n- (test infrastructure — proven by the suite itself staying green through the core reworks)\n\n## Dependencies\n\n- Depends on: none\n\n## References\n\n- [python-sdk tests/interaction](https://github.com/modelcontextprotocol/python-sdk/blob/main/tests/interaction/README.md)\n- [expected-failures baseline](https://github.com/modelcontextprotocol/python-sdk/blob/main/.github/actions/conformance/expected-failures.yml)\n","author":{"url":"https://github.com/maxisbey","@type":"Person","name":"maxisbey"},"datePublished":"2026-06-17T11:12:29.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/2905/python-sdk/issues/2905"}