Updating order of operations for applying patchers

loguru/_logger.py

@@ -2107,7 +2107,7 @@ def _log(self, level, from_decorator, options, message, args, kwargs):
             "function": co_name,
             "level": RecordLevel(level_name, level_no, level_icon),
             "line": f_lineno,
-            "message": str(message),
+            "message": message,
             "module": splitext(file_name)[0],
             "name": name,
             "process": RecordProcess(process.ident, process.name),
@@ -2130,23 +2130,25 @@ def _log(self, level, from_decorator, options, message, args, kwargs):
                 )
             kwargs.update(record=log_record)
 
+        if core.patcher:
+            core.patcher(log_record)
+
+        for patcher in patchers:
+            patcher(log_record)
+
         if colors:
             if args or kwargs:
-                colored_message = Colorizer.prepare_message(message, args, kwargs)
+                colored_message = Colorizer.prepare_message(log_record["message"], args, kwargs)
             else:
-                colored_message = Colorizer.prepare_simple_message(str(message))
+                colored_message = Colorizer.prepare_simple_message(str(log_record["message"]))
             log_record["message"] = colored_message.stripped
         elif args or kwargs:
             colored_message = None
-            log_record["message"] = message.format(*args, **kwargs)
+            log_record["message"] = log_record["message"].format(*args, **kwargs)
         else:
             colored_message = None
 
-        if core.patcher:
-            core.patcher(log_record)
-
-        for patcher in patchers:
-            patcher(log_record)
+        log_record["message"] = str(log_record["message"])
 
         for handler in core.handlers.values():
             handler.emit(log_record, level_id, from_decorator, raw, colored_message)

tests/test_patch.py

@@ -1,3 +1,7 @@
+import re
+
+import pytest
+
 from loguru import logger
 
 
@@ -83,3 +87,46 @@ def patch_3(record):
     logger.patch(patch_1).patch(patch_2).patch(patch_3).info("Test")
 
     assert writer.read() == "12 Test\n"
+
+
+@pytest.mark.parametrize(
+    ("colorize", "colors", "expected"),
+    [
+        (False, False, "<red>A</red>\n"),
+        (False, True, "A\n"),
+        (True, False, "<red>A</red>\n"),
+        (True, True, "\x1b[31mA\x1b[0m\n"),
+    ],
+)
+def test_colorful_patch(colorize, colors, expected, writer):
+    logger.add(writer, format="{message}", colorize=colorize)
+
+    logger_patched = logger.patch(lambda r: r.update(message=f"<red>{r['message']}</red>"))
+    logger_patched.opt(colors=colors).debug("A")
+
+    assert writer.read() == expected
+
+
+@pytest.mark.parametrize(
+    ("colorize", "colors", "expected"),
+    [
+        (False, False, "A <red>W</red>, <red>M</red>\n"),
+        (False, True, "A W, M\n"),
+        (True, False, "A <red>W</red>, <red>M</red>\n"),
+        (True, True, "A \x1b[31mW\x1b[0m, \x1b[31mM\x1b[0m\n"),
+    ],
+)
+def test_automatic_colorful_patch(colorize, colors, expected, writer):
+    # regex matches on single curly braces and substitutes
+    # a color tag in-place
+    _regex_pattern = re.compile(r"(\{[^{}]*\})(?!\})")
+    _regex_repl = r"<red>\1</red>"
+
+    def patch(r):
+        r.update(message=re.sub(_regex_pattern, _regex_repl, r["message"]))
+
+    logger.add(writer, format="{message}", colorize=colorize)
+    logger_patched = logger.patch(patch)
+    logger_patched.opt(colors=colors).debug("A {}, {a}", "W", a="M")
+
+    assert writer.read() == expected