Add DMTF mockup fixtures and test helpers

Unmodified files from DMTF Redfish-Publications (public-rackmount1, public-localstorage, public-telemetry), only those the tests use, each set with DMTF's BSD-3-Clause license and a COMMANDS.txt naming the source commit and request paths.

conftest.py loads them by request path and serves a mockup over mocked HTTP, with a SessionService that hands out a token, for the transport tests.

tests/conftest.py

@@ -0,0 +1,112 @@
+"""Shared helpers for loading the recorded Redfish responses under tests/fixtures/."""
+
+import json
+import re
+from pathlib import Path
+from urllib.parse import urlsplit
+
+import pytest
+import responses
+
+FIXTURES = Path(__file__).parent / "fixtures"
+PREFIX = "/redfish/v1"
+
+
+def fixture_file(mockup: str, path: str) -> Path:
+    """Map a request path to its file: /redfish/v1/X/Y -> <mockup>/X/Y/index.json."""
+    path = path.split("#", 1)[0].split("?", 1)[0].rstrip("/")
+    if not path.startswith(PREFIX):
+        raise ValueError(f"not a Redfish path: {path}")
+    relative = path[len(PREFIX):].lstrip("/")
+    return FIXTURES / mockup / relative / "index.json"
+
+
+def load(mockup: str, path: str) -> dict:
+    return json.loads(fixture_file(mockup, path).read_text())
+
+
+@pytest.fixture
+def rackmount():
+    """Loader for the DMTF public-rackmount1 mockup."""
+    return lambda path: load("dmtf-public-rackmount1", path)
+
+
+@pytest.fixture
+def localstorage():
+    """Loader for the DMTF public-localstorage mockup."""
+    return lambda path: load("dmtf-public-localstorage", path)
+
+
+@pytest.fixture
+def telemetry():
+    """Loader for the DMTF public-telemetry mockup."""
+    return lambda path: load("dmtf-public-telemetry", path)
+
+
+BASE_URL = "https://bmc.example.net"
+SESSIONS = "/redfish/v1/SessionService/Sessions"
+SESSION_PATH = SESSIONS + "/0123456789abcdef"
+TOKEN = "secret-session-token"
+
+
+class MockupServer:
+    """Serve a fixture mockup over mocked HTTP, plus a SessionService that hands out one token.
+
+    Unknown paths return a Redfish error body with 404, like a real service. ``override``
+    replaces the answer for one method and path (the path may include a query string).
+    """
+
+    def __init__(self, rsps, mockup: str):
+        self.rsps = rsps
+        self.mockup = mockup
+        self.overrides: dict[tuple[str, str], tuple[int, dict, dict]] = {}
+        anything = re.compile(re.escape(BASE_URL) + r"/.*")
+        for method in (responses.GET, responses.POST, responses.DELETE):
+            rsps.add_callback(method, anything, callback=self._handle)
+
+    def override(self, method: str, path: str, status: int, body: dict | str | None = None,
+                 headers: dict | None = None):
+        self.overrides[(method, path)] = (status, body if body is not None else {}, headers or {})
+
+    @staticmethod
+    def _reply(status, body, headers=None):
+        if isinstance(body, str):
+            text = body
+        else:
+            text = json.dumps(body) if body != {} or status != 204 else ""
+        return status, {"Content-Type": "application/json", **(headers or {})}, text
+
+    def _handle(self, request):
+        parts = urlsplit(request.url)
+        for key in ((request.method, f"{parts.path}?{parts.query}"), (request.method, parts.path)):
+            if key in self.overrides:
+                return self._reply(*self.overrides[key])
+        if request.method == "POST" and parts.path == SESSIONS:
+            return self._reply(201, {"@odata.id": SESSION_PATH, "Id": "0123456789abcdef"},
+                               {"X-Auth-Token": TOKEN, "Location": BASE_URL + SESSION_PATH})
+        if request.method == "DELETE" and parts.path == SESSION_PATH:
+            return self._reply(204, {})
+        if request.method == "GET":
+            try:
+                return self._reply(200, load(self.mockup, parts.path))
+            except (FileNotFoundError, ValueError):
+                pass
+        return self._reply(404, {"error": {"code": "Base.1.0.ResourceMissingAtURI",
+                                           "message": f"{parts.path} not found"}})
+
+    def calls(self, method: str | None = None, path: str | None = None):
+        return [c for c in self.rsps.calls
+                if (method is None or c.request.method == method)
+                and (path is None or urlsplit(c.request.url).path == path)]
+
+
+@pytest.fixture
+def http():
+    with responses.RequestsMock(assert_all_requests_are_fired=False) as rsps:
+        yield rsps
+
+
+@pytest.fixture
+def server(http):
+    """The public-rackmount1 mockup served on BASE_URL."""
+    return MockupServer(http, "dmtf-public-rackmount1")