Tidy up logging and rework tests from scratch

tests/unit/test_logging.py

@@ -0,0 +1,86 @@
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+import sys
+import tempfile
+import unittest
+
+
+SRC_ROOT = Path(__file__).resolve().parents[2] / "src"
+
+if str(SRC_ROOT) not in sys.path:
+    sys.path.insert(0, str(SRC_ROOT))
+
+
+from ffx.logging_utils import (  # noqa: E402
+    CONSOLE_HANDLER_NAME,
+    FILE_HANDLER_NAME,
+    configure_ffx_logger,
+    get_ffx_logger,
+)
+
+
+class LoggingUtilsTests(unittest.TestCase):
+    def cleanup_logger(self, logger_name: str) -> None:
+        logger = logging.getLogger(logger_name)
+        for handler in list(logger.handlers):
+            logger.removeHandler(handler)
+            handler.close()
+
+    def test_get_ffx_logger_adds_only_one_null_handler(self):
+        logger_name = "ffx-test-null-handler"
+        self.cleanup_logger(logger_name)
+
+        logger = get_ffx_logger(logger_name)
+        logger = get_ffx_logger(logger_name)
+
+        null_handlers = [
+            handler for handler in logger.handlers if isinstance(handler, logging.NullHandler)
+        ]
+        self.assertEqual(1, len(null_handlers))
+
+        self.cleanup_logger(logger_name)
+
+    def test_configure_ffx_logger_reuses_named_handlers(self):
+        logger_name = "ffx-test-configure-handler"
+        self.cleanup_logger(logger_name)
+
+        with tempfile.TemporaryDirectory() as tempdir:
+            first_log_path = Path(tempdir) / "first.log"
+            second_log_path = Path(tempdir) / "second.log"
+
+            logger = configure_ffx_logger(
+                str(first_log_path),
+                logging.ERROR,
+                logging.INFO,
+                name=logger_name,
+            )
+            logger = configure_ffx_logger(
+                str(second_log_path),
+                logging.DEBUG,
+                logging.WARNING,
+                name=logger_name,
+            )
+
+            console_handlers = [
+                handler for handler in logger.handlers if handler.get_name() == CONSOLE_HANDLER_NAME
+            ]
+            file_handlers = [
+                handler for handler in logger.handlers if handler.get_name() == FILE_HANDLER_NAME
+            ]
+
+            self.assertEqual(1, len(console_handlers))
+            self.assertEqual(1, len(file_handlers))
+            self.assertFalse(
+                any(isinstance(handler, logging.NullHandler) for handler in logger.handlers)
+            )
+            self.assertEqual(logging.WARNING, console_handlers[0].level)
+            self.assertEqual(logging.DEBUG, file_handlers[0].level)
+            self.assertEqual(str(second_log_path.resolve()), file_handlers[0].baseFilename)
+
+        self.cleanup_logger(logger_name)
+
+
+if __name__ == "__main__":
+    unittest.main()