Move unit tests to their own sub-dir in tests

tests/unit_tests/test_server_cli.py

@@ -0,0 +1,104 @@
+"""Test server booting and shut down."""
+
+import logging
+
+import pytest
+from fastapi import FastAPI
+
+# 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 import server as ofm_server
+
+from .test_server_config import FULL_CONFIG
+
+
+def test_no_config():
+    """Check that an error is thrown if no configuration is set for the microspe via CLI."""
+    with pytest.raises(RuntimeError, match="No configuration"):
+        ofm_server.serve_from_cli([])
+
+
+def test_successful_start(mocker, caplog):
+    """Check some basic things from the microscope setup.
+
+    This test checks that logging is set up and that the actual function used for
+    handling shutdown events shuts down the mjpeg streams.
+    """
+    mock_server = mocker.Mock()
+    # Create a mock for the camera so we can check the MJPEG streams are closed on
+    # shutdown.
+    mock_camera = mocker.Mock()
+    mock_server.things = {"camera": mock_camera}
+    # Mock the LabThings function that returns the server so we have a mock server
+    mocker.patch(
+        "openflexure_microscope_server.server.lt.ThingServer.from_config",
+        return_value=mock_server,
+    )
+    # Also mock customisation or it will try to access the hard drive and make files.
+    mock_customise = mocker.patch.object(ofm_server, "customise_server")
+    # And mock uvicorn.run as we don't want to start a server process
+    mock_uvicorn_run = mocker.patch("openflexure_microscope_server.server.uvicorn.run")
+
+    # Run the mock CLI
+    ofm_server.serve_from_cli(["-c", FULL_CONFIG])
+
+    # Check that the server was customised and the run
+    assert mock_customise.call_count == 1
+    assert mock_uvicorn_run.call_count == 1
+    # Read the log config that was set
+    log_config = mock_uvicorn_run.call_args.kwargs["log_config"]
+    # Check both uvicorn loggers were set to propagate
+    assert log_config["loggers"]["uvicorn"]["propagate"]
+    assert log_config["loggers"]["uvicorn.access"]["propagate"]
+
+    # Now Mock a shutdown signal being sent
+    ofm_server.Server.handle_exit(mock_server.app, "mock_signal", "mock_frame")
+
+    # Check
+    assert mock_camera.kill_mjpeg_streams.call_count == 1
+
+    # Mock shutdown again but with the MJPEG stream throwing a BaseException
+    mock_camera.kill_mjpeg_streams.side_effect = BaseException("mock-54321")
+
+    # This should log at error level but even a BaseException will not cause an error
+    # that stops the shutdown signal propagating
+    with caplog.at_level(logging.ERROR):
+        ofm_server.Server.handle_exit(mock_server.app, "mock_signal", "mock_frame")
+    # Assert there is one error log
+    assert len(caplog.records) == 1
+    # And that it is the message raised by the kill_mjpeg_streams mock
+    assert str(caplog.records[0].msg) == "mock-54321"
+
+
+def test_failed_customise(mocker):
+    """Check what happens if there is an error before the server is started by uvicorn.
+
+    This differs based on whether the --fallback flag is set.
+    """
+    mock_server = mocker.Mock()
+    # Mock the LabThings function that returns the server so we have a mock server
+    mocker.patch(
+        "openflexure_microscope_server.server.lt.ThingServer.from_config",
+        return_value=mock_server,
+    )
+    # Also mock customisation or it will try to access the hard drive and make files.
+    mocker.patch.object(
+        ofm_server, "customise_server", side_effect=RuntimeError("Can't touch this")
+    )
+    # And mock uvicorn.run as we don't want to start a server process
+    mock_uvicorn_run = mocker.patch("openflexure_microscope_server.server.uvicorn.run")
+
+    # Running the mock CLI will error
+    with pytest.raises(RuntimeError, match="Can't touch this"):
+        ofm_server.serve_from_cli(["-c", FULL_CONFIG])
+
+    # But with the fallback flag uvicorn run will be run
+    ofm_server.serve_from_cli(["-c", FULL_CONFIG, "--fallback"])
+
+    assert mock_uvicorn_run.call_count == 1
+    # Get the fallback app passed to uvicorn tun
+    fallback_app = mock_uvicorn_run.call_args.args[0]
+    # Check it really is a fastapi
+    assert isinstance(fallback_app, FastAPI)
+    # An that it has the error to display
+    assert str(fallback_app.labthings_error) == "Can't touch this"