test: add MCP smoke tests over stdio and streamable HTTP, from source and from the built image

tests/mcp/conftest.py

@@ -0,0 +1,76 @@
+"""Opt-in fixtures for the MCP smoke tests.
+
+Tests in this directory are marked ``mcp_smoke`` and skipped unless
+``AEGIS_INTEGRATION=1``. They reuse the live-Gitea harness from
+``tests/integration`` (one disposable Gitea per session, admin token with the
+``all`` scope) and drive the server through a real MCP client over stdio and
+streamable HTTP, from source and (when ``AEGIS_MCP_IMAGE`` is set) from the
+built image.
+"""
+
+from __future__ import annotations
+
+import os
+import secrets
+from pathlib import Path
+
+import pytest
+
+from tests.integration.conftest import ENABLE_ENV, gitea, integration_enabled
+from tests.integration.harness import GITEA_PORT, GiteaInstance
+
+__all__ = ["ENABLE_ENV", "gitea"]
+
+_HERE = Path(__file__).parent.resolve()
+IMAGE_ENV = "AEGIS_MCP_IMAGE"
+
+
+def pytest_configure(config: pytest.Config) -> None:
+    """Register the ``mcp_smoke`` marker (idempotent with pyproject)."""
+    config.addinivalue_line(
+        "markers", "mcp_smoke: MCP client smoke tests, opt-in via AEGIS_INTEGRATION=1"
+    )
+
+
+def _is_mcp_smoke(item: pytest.Item) -> bool:
+    try:
+        return _HERE in Path(str(item.path)).resolve().parents
+    except (OSError, ValueError):  # pragma: no cover - defensive
+        return False
+
+
+def pytest_collection_modifyitems(config: pytest.Config, items: list[pytest.Item]) -> None:
+    """Mark and (unless opted in) skip every test under tests/mcp."""
+    selected = [item for item in items if _is_mcp_smoke(item)]
+    skip = pytest.mark.skip(reason=f"MCP smoke tests need {ENABLE_ENV}=1 and Docker")
+    for item in selected:
+        item.add_marker(pytest.mark.mcp_smoke)
+        if not integration_enabled():
+            item.add_marker(skip)
+    if selected and len(selected) == len(items):
+        # A smoke-only run starts the server in subprocesses, so the in-process
+        # coverage gate does not apply.
+        for namespace in (config.option, config.known_args_namespace):
+            if getattr(namespace, "cov_fail_under", None) is not None:
+                namespace.cov_fail_under = 0
+
+
+@pytest.fixture(scope="session")
+def gitea_internal_url(gitea: GiteaInstance) -> str:
+    """URL of the Gitea container for other containers on the harness network."""
+    return f"http://{gitea.container}:{GITEA_PORT}"
+
+
+@pytest.fixture(scope="session")
+def mcp_image() -> str:
+    """The built image under test; the test is skipped when ``AEGIS_MCP_IMAGE`` is unset."""
+    image = os.environ.get(IMAGE_ENV, "").strip()
+    if not image:
+        pytest.skip(f"{IMAGE_ENV} is not set; image smoke tests need a built image")
+    return image
+
+
+@pytest.fixture
+def bearer_token() -> str:
+    """A random 48 character MCP bearer token."""
+    return secrets.token_urlsafe(36)