Map method name in capture_logs as well

CHANGELOG.md

@@ -15,6 +15,11 @@ You can find our backwards-compatibility policy [here](https://github.com/hynek/
 
 ## [Unreleased](https://github.com/hynek/structlog/compare/24.2.0...HEAD)
 
+### Changed
+
+- `structlog.testing.capture_logs()` now maps the `exception` log level to `error` (as it's elsewhere).
+  [#628](https://github.com/hynek/structlog/pull/628)
+
 
 ## [24.2.0](https://github.com/hynek/structlog/compare/24.1.0...24.2.0) - 2024-05-27
 

src/structlog/_log_levels.py

@@ -46,6 +46,18 @@
 _NAME_TO_LEVEL = NAME_TO_LEVEL
 
 
+def map_method_name(method_name: str) -> str:
+    # warn is just a deprecated alias in the stdlib.
+    if method_name == "warn":
+        return "warning"
+
+    # Calling exception("") is the same as error("", exc_info=True)
+    if method_name == "exception":
+        return "error"
+
+    return method_name
+
+
 def add_log_level(
     logger: logging.Logger, method_name: str, event_dict: EventDict
 ) -> EventDict:
@@ -63,13 +75,7 @@ def add_log_level(
     .. versionchanged:: 24.1.0
        Added mapping from "exception" to "error"
     """
-    if method_name == "warn":
-        # The stdlib has an alias
-        method_name = "warning"
-    elif method_name == "exception":
-        # exception("") method is the same as error("", exc_info=True)
-        method_name = "error"
 
-    event_dict["level"] = method_name
+    event_dict["level"] = map_method_name(method_name)
 
     return event_dict

src/structlog/testing.py

@@ -17,6 +17,7 @@
 from typing import Any, Generator, NamedTuple, NoReturn
 
 from ._config import configure, get_config
+from ._log_levels import map_method_name
 from .exceptions import DropEvent
 from .typing import EventDict, WrappedLogger
 
@@ -41,6 +42,10 @@ class LogCapture:
     :ivar List[structlog.typing.EventDict] entries: The captured log entries.
 
     .. versionadded:: 20.1.0
+
+    .. versionchanged:: 24.3.0
+       Added mapping from "exception" to "error"
+       Added mapping from "warn" to "warning"
     """
 
     entries: list[EventDict]
@@ -51,7 +56,7 @@ def __init__(self) -> None:
     def __call__(
         self, _: WrappedLogger, method_name: str, event_dict: EventDict
     ) -> NoReturn:
-        event_dict["log_level"] = method_name
+        event_dict["log_level"] = map_method_name(method_name)
         self.entries.append(event_dict)
 
         raise DropEvent

tests/test_testing.py

@@ -5,6 +5,8 @@
 
 import pytest
 
+import structlog
+
 from structlog import get_config, get_logger, testing
 from structlog.testing import (
     CapturedCall,
@@ -85,6 +87,35 @@ def test_captures_bound_logers(self):
             }
         ]
 
+    def test_captures_log_level_mapping(self):
+        """
+        exceptions and warn log levels are mapped like in regular loggers.
+        """
+        structlog.configure(
+            processors=[
+                structlog.stdlib.ProcessorFormatter.wrap_for_formatter,
+            ],
+            logger_factory=structlog.stdlib.LoggerFactory(),
+            wrapper_class=structlog.stdlib.BoundLogger,
+        )
+        with testing.capture_logs() as logs:
+            get_logger().exception("hello", answer=42)
+            get_logger().warn("again", answer=23)
+
+        assert [
+            {
+                "event": "hello",
+                "answer": 42,
+                "exc_info": True,
+                "log_level": "error",
+            },
+            {
+                "answer": 23,
+                "event": "again",
+                "log_level": "warning",
+            },
+        ] == logs
+
 
 class TestReturnLogger:
     # @pytest.mark.parametrize("method", stdlib_log_methods)