Deterministic bridge E2E

bridge_smoke.py drives a live Unity Editor over the real wire path (send_command_with_retry) with a fixed sequence of tool calls and exact assertions. It is the no-LLM counterpart to claude-nl-suite.yml: deterministic, free (no Anthropic API key), and therefore safe to gate PRs.

It is not collected by pytest tests/ (the filename is not test_*.py), so the normal unit suite never tries to reach a Unity instance.

Run locally

Start a Unity Editor with the MCP bridge active, then:

cd Server
uv run python tests/e2e/bridge_smoke.py            # auto-discovers the instance
uv run python tests/e2e/bridge_smoke.py --instance MyProject@<hash>

Exit codes: 0 all steps passed · 1 a step failed an assertion (real bridge regression) · 2 no Unity bridge reachable (setup problem, not a contract bug).

CI

.github/workflows/e2e-bridge.yml boots headless Unity via McpForUnity.Editor.McpCiBoot.StartStdioForCi (the same step the NL suite uses), waits for the bridge status file, then runs this driver. It triggers on PRs that touch MCPForUnity/Editor, MCPForUnity/Runtime, or Server/src, and on workflow_dispatch. It self-skips (does not fail) when Unity license secrets are absent.

Adding steps

Append a Step(...) in build_steps() with a check(resp) callback that raises AssertionError on failure. Use _ok() / _result() to stay tolerant of both Unity response shapes. Keep new objects uniquely named (see the _RUN suffix) and delete anything you create so reruns stay clean.