Add MregCliLogger tests and fix logging configuration

mreg_cli/log.py

@@ -65,6 +65,7 @@ def start_logging(
                 level=level.as_int(),
                 format=fmt,
                 datefmt="%Y-%m-%d %H:%M:%S",
+                force=True,
             )
         except Exception as e:
             print(f"Failed to set up logging: {e}", file=sys.stderr)

tests/test_log.py

@@ -0,0 +1,104 @@
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+
+from inline_snapshot import snapshot
+
+from mreg_cli.log import MregCliLogger
+
+# NOTE: we cannot use caplog fixture together with `MregCliLogger`, because
+# `start_logging` does nothing if logging already has handlers (which is the case when caplog is used),
+# and `stop_logging` removes the caplog handlers.
+
+
+def test_logging_start(tmp_path: Path) -> None:
+    logfile = tmp_path / "test.log"
+    mreg_logger = MregCliLogger()
+    mreg_logger.start_logging(logfile, "DEBUG")
+
+    logger = logging.getLogger("test_logging_start")
+    logger.debug("This is a debug message.")
+    logger.info("This is an info message.")
+    logger.warning("This is a warning message.")
+    logger.error("This is an error message.")
+    logger.critical("This is a critical message.")
+
+    # Stop logging to flush buffer to the file
+    mreg_logger.stop_logging()
+
+    # 5 log messages should be written
+    assert logfile.read_text().count("\n") == snapshot(5)
+
+
+def test_mregclilogger_singleton(tmp_path: Path) -> None:
+    """Ensure that MregCliLogger behaves as a singleton."""
+    logfile = tmp_path / "singleton.log"
+
+    # 2 loggers
+    logger = MregCliLogger()
+    logger2 = MregCliLogger()
+
+    # Do some setup on the first instance
+    logger.stop_logging()
+    logger.start_logging(logfile, "INFO")
+
+    # Ensure both instances + new calls are the same object
+    assert logger is logger2
+    assert logger is MregCliLogger()
+
+    # Status should be the same
+    assert logger.status == logger2.status
+
+
+def test_mregclilogger_status_as_str_stderr() -> None:
+    """Test logging status when logging to stderr."""
+    logger = MregCliLogger()
+    logger.stop_logging()
+    logger.start_logging(None, "INFO")
+    status = logger.status
+    assert status.as_str() == snapshot("INFO > stderr")
+
+
+def test_mregclilogger_status_as_str_file(tmp_path: Path) -> None:
+    logfile = tmp_path / "test.log"
+
+    logger = MregCliLogger()
+    logger.stop_logging()
+
+    # Actually start logging to the real temp file
+    logger.start_logging(logfile, "INFO")
+
+    # Test output with actual temp file path (random pytest dir)
+    status = logger.status
+    assert status.as_str().startswith("INFO > /")
+
+    # Deterministic output with overriden file path
+    logger._file = Path("/path/to/logfile.log")
+    assert logger.status.as_str() == snapshot("INFO > /path/to/logfile.log")
+
+
+def test_mregclilogger_status_as_str_disabled() -> None:
+    """Test logging status when logging is disabled."""
+    logger = MregCliLogger()
+    logger.stop_logging()
+    status = logger.status
+    assert status.as_str() == snapshot("disabled")
+
+
+def test_log_handlers_multiple_restarts(tmp_path: Path) -> None:
+    """Test that handlers are flushed when starting logging multiple times."""
+    logger = MregCliLogger()
+    logger.stop_logging()
+
+    # Start logging first time
+    logger.start_logging(tmp_path / "test.log.1", "INFO")
+    handlers_after_first_start = logging.getLogger().handlers.copy()
+
+    # Start logging second time
+    logger.start_logging(tmp_path / "test.log.2", "INFO")
+    handlers_after_second_start = logging.getLogger().handlers.copy()
+
+    # Should have the same number of handlers, but different instances
+    assert len(handlers_after_first_start) == len(handlers_after_second_start)
+    assert handlers_after_first_start != handlers_after_second_start