Allow positional args in exception (#531)

src/structlog/_log_levels.py

@@ -80,13 +80,17 @@ async def _anop(self: Any, event: str, *args: Any, **kw: Any) -> Any:
     return None
 
 
-def exception(self: FilteringBoundLogger, event: str, **kw: Any) -> Any:
+def exception(
+    self: FilteringBoundLogger, event: str, *args: Any, **kw: Any
+) -> Any:
     kw.setdefault("exc_info", True)
 
-    return self.error(event, **kw)
+    return self.error(event, *args, **kw)
 
 
-async def aexception(self: FilteringBoundLogger, event: str, **kw: Any) -> Any:
+async def aexception(
+    self: FilteringBoundLogger, event: str, *args: Any, **kw: Any
+) -> Any:
     # Exception info has to be extracted this early, because it is no longer
     # available once control is passed to the executor.
     if kw.get("exc_info", True) is True:
@@ -95,7 +99,7 @@ async def aexception(self: FilteringBoundLogger, event: str, **kw: Any) -> Any:
     ctx = contextvars.copy_context()
     return await asyncio.get_running_loop().run_in_executor(
         None,
-        lambda: ctx.run(lambda: self.error(event, **kw)),
+        lambda: ctx.run(lambda: self.error(event, *args, **kw)),
     )
 
 

tests/test_log_levels.py

@@ -195,6 +195,24 @@ async def test_async_exception(self, bl, cl):
         assert isinstance(cl.calls[0][2]["exc_info"], tuple)
         assert exc == cl.calls[0][2]["exc_info"][1]
 
+    def test_exception_positional_args(self, bl, cl):
+        """
+        exception allows for positional args
+        """
+        bl.exception("%s %s", "boom", "bastic")
+
+        assert [
+            ("error", (), {"event": "boom bastic", "exc_info": True})
+        ] == cl.calls
+
+    async def test_aexception_positional_args(self, bl, cl):
+        """
+        aexception allows for positional args
+        """
+        await bl.aexception("%s %s", "boom", "bastic")
+        assert 1 == len(cl.calls)
+        assert "boom bastic" == cl.calls[0][2]["event"]
+
     async def test_async_exception_true(self, bl, cl):
         """
         aexception replaces exc_info with current exception info, if exc_info