Remove unreachable emoji entries and add use_emoji

CHANGELOG.md

@@ -36,6 +36,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
   version, and creates a GitHub release. The process is documented in
   `docs/releasing.md`. Publishing to PyPI is deliberately left out until the
   distribution name is settled (#20).
+- `setup_logging(use_emoji=...)` turns the level emoji in the verbose console
+  layout off (#25).
 
 ### Changed
 
@@ -119,3 +121,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
   fields. Before, they had only the message and the context. The internal
   `emoji` and `context` fields no longer leak into JSON, and the output is
   identical across python-json-logger 2.x and later releases (#42).
+- The emoji map listed levels that are never registered (`SYSTEM`, `SECURITY`,
+  `NETWORK`, `DATABASE`, `STARTUP`, `SHUTDOWN`) and could never match, so they
+  were removed. The level name is no longer followed by a stray space when a
+  level has no emoji (#25).

README.md

@@ -115,6 +115,7 @@ log.info("this one is carol's", extra={"user_id": "carol"})
 | `to_console` | `True` | Log to the console. |
 | `console_level` | `None` | Console level, defaulting to `level`. |
 | `console_stream` | `None` | Console stream, for example `sys.stderr`. Defaults to `sys.stdout`. |
+| `use_emoji` | `True` | Show a level emoji in the verbose console layout. Set `False` for terminals that render emoji badly. |
 | `mode` | `"verbose"` | Console layout: `"verbose"` (coloured, with source location and context) or `"compact"` (`[LEVEL] message`). |
 | `use_json` | `False` | Write JSON lines to the console instead. Needs the `json` extra. |
 | `to_file` | `False` | Log to `file_path`. |

pylogkit/log_setup.py

@@ -75,6 +75,14 @@
 SYSLOG_FORMAT = "%(name)s[%(process)d]: %(levelname)s %(context)s - %(message)s"
 
 # One colour per level, used for the level name and for the message text.
+_LEVEL_EMOJI = {
+    "DEBUG": "🐛",
+    "INFO": "ℹ️",
+    "WARNING": "⚠️",
+    "ERROR": "❌",
+    "CRITICAL": "💥",
+}
+
 _LEVEL_COLOURS = {
     "DEBUG": "cyan",
     "INFO": "blue",
@@ -191,7 +199,7 @@ def _build_console_formatter(stream: IO[str] | None = None) -> SmartFieldFormatt
     """
     return SmartFieldFormatter(
         fmt=f"%({COLOUR_TIMESTAMP})s%(asctime)s%(reset)s "
-        "[%(log_color)s%(levelname)s %(emoji)s%(reset)s] "
+        "[%(log_color)s%(levelname)s%(emoji)s%(reset)s] "
         f"[%({COLOUR_MODULE_NAME})s%(name)s%(reset)s] "
         f"%({COLOUR_FILENAME})s%(filename)s%(reset)s::"
         f"%({COLOUR_FUNCTION})s%(funcName)s%(reset)s():"
@@ -214,28 +222,29 @@ class ContextFilter(logging.Filter):
     Values already present on the record (for example those supplied through
     ``extra=`` or by :class:`ContextualLoggerAdapter`) take precedence over
     the global context.
+
+    Args:
+        use_emoji: Set ``record.emoji`` to the level's emoji (preceded by a
+            space, so that it lines up after the level name). When false the
+            field is empty.
     """
 
+    def __init__(self, use_emoji: bool = True) -> None:
+        """Create the filter, optionally without level emoji."""
+        super().__init__()
+        self._use_emoji = use_emoji
+
     def filter(self, record: logging.LogRecord) -> bool:
         """Add the context fields and emoji to ``record`` and accept it."""
         context = get_log_context()
         for k, v in context.items():
             if not hasattr(record, k):
                 setattr(record, k, v)
-        emoji_map = {
-            "DEBUG": "🐛",
-            "INFO": "ℹ️",
-            "WARNING": "⚠️",
-            "ERROR": "❌",
-            "CRITICAL": "💥",
-            "SYSTEM": "🖥️",
-            "SECURITY": "🔐",
-            "NETWORK": "🌐",
-            "DATABASE": "🗄️",
-            "STARTUP": "🚀",
-            "SHUTDOWN": "🛑",
-        }
-        record.emoji = emoji_map.get(record.levelname, "")
+        record.emoji = (
+            f" {_LEVEL_EMOJI[record.levelname]}"
+            if self._use_emoji and record.levelname in _LEVEL_EMOJI
+            else ""
+        )
         return True
 
 
@@ -365,6 +374,7 @@ def setup_logging(
     syslog_address: tuple[str, int] | str = ("localhost", 514),
     syslog_facility: int = SysLogHandler.LOG_USER,
     console_stream: IO[str] | None = None,
+    use_emoji: bool = True,
 ) -> logging.Logger:
     """Configure and return a logger with console, file, JSON and syslog output.
 
@@ -413,6 +423,9 @@ def setup_logging(
             Console colour is disabled when the stream is not a terminal, when
             ``NO_COLOR`` is set or ``TERM`` is ``dumb``, unless ``FORCE_COLOR``
             is set.
+        use_emoji: Show a level emoji after the level name in the verbose
+            console layout. Set it to false for terminals and log viewers
+            that render emoji badly.
 
     Returns:
         The configured :class:`logging.Logger`.
@@ -476,7 +489,7 @@ def setup_logging(
         syslog_handler.setFormatter(syslog_formatter)
         logger.addHandler(syslog_handler)
 
-    context_filter = ContextFilter()
+    context_filter = ContextFilter(use_emoji=use_emoji)
     for handler in logger.handlers:
         handler.addFilter(context_filter)
 

tests/test_emoji.py

@@ -0,0 +1,44 @@
+"""Tests for the level emoji in the verbose console layout."""
+
+import logging
+
+from pylogkit import log_setup, setup_logging
+
+STANDARD_LEVELS = {"DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"}
+
+
+def test_emoji_map_only_names_registered_levels():
+    """Every emoji entry belongs to a level that exists, so none is dead code."""
+    registered = {logging.getLevelName(n) for n in (10, 20, 30, 40, 50)}
+
+    assert set(log_setup._LEVEL_EMOJI) == STANDARD_LEVELS == registered
+
+
+def test_emoji_is_shown_by_default(capsys):
+    """The verbose layout puts the emoji right after the level name."""
+    setup_logging("emoji-on", level="DEBUG")
+
+    logging.getLogger("emoji-on").error("boom")
+
+    assert "[ERROR ❌]" in capsys.readouterr().out
+
+
+def test_emoji_can_be_disabled(capsys):
+    """Without emoji the level name is not followed by stray spacing."""
+    setup_logging("emoji-off", use_emoji=False)
+
+    logging.getLogger("emoji-off").error("boom")
+
+    out = capsys.readouterr().out
+    assert "[ERROR]" in out
+    assert "❌" not in out
+
+
+def test_unknown_level_has_no_emoji_and_no_spacing(capsys):
+    """A custom level prints cleanly."""
+    logging.addLevelName(25, "NOTICE")
+    setup_logging("emoji-custom", level="DEBUG")
+
+    logging.getLogger("emoji-custom").log(25, "custom")
+
+    assert "[NOTICE]" in capsys.readouterr().out