Move unit tests to their own sub-dir in tests

tests/unit_tests/test_logging.py

@@ -0,0 +1,187 @@
+"""Test the server's logging configuration and handling."""
+
+import logging
+import os
+import tempfile
+
+import pytest
+from fastapi import HTTPException
+from fastapi.responses import PlainTextResponse
+
+from openflexure_microscope_server import logging as ofm_logging
+
+
+def test_no_warnings_if_correct_permissions(caplog):
+    """Check that configure_logging no warnings on normal operation.
+
+    Checking that:
+
+    * The logger can be set up without warnings.
+    * That the log file is created.
+    * That the log file contains the expected message about setting up the logger.
+    """
+    # Reset handler at start of test
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    with caplog.at_level(logging.WARNING), tempfile.TemporaryDirectory() as tmpdir:
+        ofm_logging.configure_logging(tmpdir)
+        assert len(caplog.records) == 0
+        with open(ofm_logging.OFM_LOG_FILE, "r", encoding="utf-8") as log_file:
+            log_txt = log_file.read()
+        assert "OFM server root logger has been set up at INFO level" in log_txt
+        root_logger = logging.getLogger()
+        assert ofm_logging.OFM_HANDLER in root_logger.handlers
+
+
+def test_permission_error_raises_warning(mocker, caplog):
+    """Check that configure_logging raises warning on PermissionError."""
+    mocker.patch(
+        "openflexure_microscope_server.logging.RotatingFileHandler",
+        side_effect=PermissionError("Permission denied"),
+    )
+    # Reset handler at start of test
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    with caplog.at_level(logging.WARNING), tempfile.TemporaryDirectory() as tmpdir:
+        ofm_logging.configure_logging(tmpdir)
+        assert len(caplog.records) == 1
+        # Check OFM logger is added even if the file logger couldn't be.
+        root_logger = logging.getLogger()
+        assert ofm_logging.OFM_HANDLER in root_logger.handlers
+
+
+def test_making_log_dir(caplog):
+    """Check that configure_logging will make a dir if needed."""
+    # Reset handler at start of test
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    with caplog.at_level(logging.WARNING), tempfile.TemporaryDirectory() as tmpdir:
+        log_dir = os.path.join(tmpdir, "new_dir")
+        assert not os.path.isdir(log_dir)
+        ofm_logging.configure_logging(log_dir)
+        assert len(caplog.records) == 0
+        assert os.path.isdir(log_dir)
+
+
+def test_max_logs():
+    """Proclaim that only the most recent 250 logs are stored in memory."""
+    # Reset handler at start of test
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    with tempfile.TemporaryDirectory() as tmpdir:
+        ofm_logging.configure_logging(tmpdir)
+        # But I would log five hundred times.
+        for i in range(500):
+            logging.info("log %s", i)
+        logs = ofm_logging.OFM_HANDLER.log_history.split("\n")
+        assert len(logs) == 250
+        assert logs[0].endswith("log 250")
+        assert logs[-1].endswith("log 499")
+        # And I would log five hundred more.
+        for i in range(500):
+            logging.info("log %s", 500 + i)
+        # Just to be the test who logged a thousand times to check your hand-el-or!
+        logs = ofm_logging.OFM_HANDLER.log_history.split("\n")
+        assert len(logs) == 250
+        assert logs[0].endswith("log 750")
+        assert logs[-1].endswith("log 999")
+
+
+def test_ofm_handler_ignores_uvicorn_access():
+    """Check uvicorn.access logs are ignored by custom handler.
+
+    The uvicorn.access logger logs every time an endpoint is triggered.
+    """
+    # Reset handler at start of test
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    with tempfile.TemporaryDirectory() as tmpdir:
+        ofm_logging.configure_logging(tmpdir)
+        logs = ofm_logging.OFM_HANDLER.log_history.split("\n")
+        starting_len = len(logs)
+        logging.info("Root 1")
+        uvicorn_logger = logging.getLogger("uvicorn.access")
+        for i in range(500):
+            uvicorn_logger.info("Uvicorn log %s", i)
+        logging.info("Root 2")
+        logs = ofm_logging.OFM_HANDLER.log_history.split("\n")
+        assert len(logs) == starting_len + 2
+        assert logs[starting_len].endswith("Root 1")
+        assert logs[-1].endswith("Root 2")
+
+
+def test_server_responses():
+    """Check that the FastAPI responses from the server are as expected.
+
+    * retrieve_log() -> PlainTextResponse containing the last 250 logs separated by
+        a new line
+    * retrieve_log_from_file() -> All the logs from the log file.
+    """
+    # Reset handler at start of test
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    with tempfile.TemporaryDirectory() as tmpdir:
+        ofm_logging.configure_logging(tmpdir)
+        for i in range(500):
+            logging.info("log %s", i)
+        log_response = ofm_logging.retrieve_log()
+        assert isinstance(log_response, PlainTextResponse)
+        logs = log_response.body.decode().split("\n")
+        assert len(logs) == 250
+        file_log_response = ofm_logging.retrieve_log_from_file()
+        assert isinstance(file_log_response, PlainTextResponse)
+        file_logs = file_log_response.body.decode().split("\n")
+        assert len(file_logs) > 500
+
+
+def test_server_response_with_no_log_file():
+    """Check that an HTTP exception is raised if logging isn't configured."""
+    # Reset handler at start of test
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    # Also Reset log file global
+    ofm_logging.OFM_LOG_FILE = None
+    with pytest.raises(HTTPException) as excinfo:
+        ofm_logging.retrieve_log_from_file()
+    assert excinfo.value.status_code == 500
+
+
+def test_server_response_with_no_log_dir():
+    """Check that an HTTP exception is raised if the log file cannot be accessed."""
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    with tempfile.TemporaryDirectory() as tmpdir:
+        ofm_logging.configure_logging(tmpdir)
+        for i in range(500):
+            logging.info("log %s", i)
+        file_log_response = ofm_logging.retrieve_log_from_file()
+        assert isinstance(file_log_response, PlainTextResponse)
+    # Close and delete the log folder, this should create an error.
+    with pytest.raises(HTTPException) as excinfo:
+        ofm_logging.retrieve_log_from_file()
+    assert excinfo.value.status_code == 500
+
+
+FAKE_UVICORN_LOGGER = logging.getLogger("uvicorn.error")
+
+
+@pytest.mark.parametrize(
+    ("log_command", "names_in_log", "names_not_in_log"),
+    [
+        (FAKE_UVICORN_LOGGER.debug, [], ["<uvicorn>", "<uvicorn.error>"]),
+        (FAKE_UVICORN_LOGGER.info, ["<uvicorn>"], ["<uvicorn.error>"]),
+        (FAKE_UVICORN_LOGGER.warning, ["<uvicorn>"], ["<uvicorn.error>"]),
+        (FAKE_UVICORN_LOGGER.error, ["<uvicorn.error>"], ["<uvicorn>"]),
+        (FAKE_UVICORN_LOGGER.exception, ["<uvicorn.error>"], ["<uvicorn>"]),
+    ],
+)
+def test_uvicorn_error_only_says_error_on_error(
+    log_command, names_in_log, names_not_in_log
+):
+    """Check that an HTTP exception is raised if the log file cannot be accessed.
+
+    Parametrised to check: debug doesn't log, info and warning log as <uvicorn>, and
+    error logs as <uvicorn.error>.
+    """
+    ofm_logging.OFM_HANDLER = ofm_logging.OFMHandler()
+    with tempfile.TemporaryDirectory() as tmpdir:
+        ofm_logging.configure_logging(tmpdir)
+        log_command("Mockety mock mock!")
+        with open(ofm_logging.OFM_LOG_FILE, "r", encoding="utf-8") as log_file:
+            log_txt = log_file.read()
+        for name in names_in_log:
+            assert name in log_txt
+        for name in names_not_in_log:
+            assert name not in log_txt