Add tests for the legacy api

src/openflexure_microscope_server/server/legacy_api.py

@@ -4,8 +4,20 @@ import labthings_fastapi as lt
 from fastapi import Response
 from socket import gethostname
 
+FAKE_ROUTES = [
+    "/api/v2/",
+    "/api/v2/streams/snapshot",
+    "/api/v2/instrument/settings/name",
+]
 
-def add_v2_endpoints(thing_server: lt.ThingServer):
+
+class JPEGResponse(Response):
+    """A FastAPI response with media_type set for a JPEG image."""
+
+    media_type = "image/jpeg"
+
+
+def add_v2_endpoints(thing_server: lt.ThingServer) -> None:
     """Add the v2 API endpoints for OpenFlexure Connect discoverability."""
     app = thing_server.app
 
@@ -19,15 +31,7 @@ def add_v2_endpoints(thing_server: lt.ThingServer):
 
         This is used by OF Connect to identify the microscope.
         """
-        fake_routes = [
+        return {url: {"url": url, "methods": ["GET"]} for url in FAKE_ROUTES}
-            "/api/v2/",
-            "/api/v2/streams/snapshot",
-            "/api/v2/instrument/settings/name",
-        ]
-        return {url: {"url": url, "methods": ["GET"]} for url in fake_routes}
-
-    class JPEGResponse(Response):
-        media_type = "image/jpeg"
 
     @app.get("/api/v2/streams/snapshot")
     @app.head("/api/v2/streams/snapshot")

tests/test_legacy_api.py

@@ -0,0 +1,63 @@
+"""Test server booting and shut down."""
+
+from socket import gethostname
+import asyncio
+
+# Import as ofm server to attempt to minimise confusion with server as a var in other
+# functions and also FastAPI `Server`.
+from openflexure_microscope_server.server import legacy_api
+
+
+def test_v2_endpoints(mocker):
+    """Check that the expected v2 endpoints are added."""
+    mock_server = mocker.Mock()
+    # Mock the camera thing to mocke the lores_mjpeg stream get_frame()
+    mock_server.things = {"/camera/": mocker.Mock()}
+    mock_server.things["/camera/"].lores_mjpeg_stream.grab_frame = mocker.AsyncMock(
+        return_value="Mock Frame"
+    )
+    mock_app = mock_server.app
+    # The wrapper returned for app.get so we can see what functions are decorated.
+    get_wrapper = mock_app.get.return_value
+    head_wrapper = mock_app.head.return_value
+
+    legacy_api.add_v2_endpoints(mock_server)
+
+    assert get_wrapper.call_count == 3
+    assert head_wrapper.call_count == 1
+
+    # The calls for the get decorator and the internal wrapper
+    get_and_wrapper_calls = zip(
+        mock_app.get.call_args_list, get_wrapper.call_args_list, strict=True
+    )
+    # Pull out the first arg of each to get the route and wrapped function, save as a
+    # dictionary - route: function
+    routes = {
+        get_call.args[0]: wrapper_call.args[0]
+        for get_call, wrapper_call in get_and_wrapper_calls
+    }
+
+    # Check the fake routes are set
+    assert "/routes" in routes
+    fake_routes_dict = routes["/routes"]()
+    assert isinstance(fake_routes_dict, dict)
+    for fake_route in legacy_api.FAKE_ROUTES:
+        assert fake_route in fake_routes_dict
+        assert fake_routes_dict[fake_route]["url"] == fake_route
+        assert fake_routes_dict[fake_route]["methods"] == ["GET"]
+
+    # Check snapshot returns a jupeg response from the async get_frame of the
+    # lores_mjpeg_stream
+    assert "/api/v2/streams/snapshot" in routes
+    # First get the async frame function from the head wrapper
+    get_frames_func = head_wrapper.call_args.args[0]()
+    assert routes["/api/v2/streams/snapshot"] == head_wrapper()
+
+    jpg_response = asyncio.run(get_frames_func)
+    assert isinstance(jpg_response, legacy_api.JPEGResponse)
+    # Value should be set as mocked rather than a frame
+    assert jpg_response.body.decode() == "Mock Frame"
+
+    # Also check the name is the hostname.
+    assert "/api/v2/instrument/settings/name" in routes
+    assert routes["/api/v2/instrument/settings/name"]() == gethostname()