fix: CapturedIO.__init__ type annotations to accept Optional[StringIO]

eachimei · eachimei · commit fd1a2848bb4f · 2026-03-30T11:20:14.000+03:00
diff --git a/IPython/utils/capture.py b/IPython/utils/capture.py
@@ -74,7 +74,12 @@ class CapturedIO:
     above in the same order, and can be invoked simply via ``c()``.
     """
 
-    def __init__(self, stdout: StringIO, stderr: StringIO, outputs: Optional[List[Any]]=None):
+    def __init__(
+        self,
+        stdout: Optional[StringIO],
+        stderr: Optional[StringIO],
+        outputs: Optional[List[Any]] = None,
+    ):
         self._stdout = stdout
         self._stderr = stderr
         if outputs is None:
diff --git a/tests/test_capture.py b/tests/test_capture.py
@@ -168,3 +168,11 @@ def test_capture_output_no_display():
     assert hello_stdout == cap.stdout
     assert hello_stderr == cap.stderr
     assert cap.outputs == []
+
+
+def test_captured_io_none_streams():
+    """CapturedIO accepts None for stdout/stderr and returns empty strings."""
+    cap = capture.CapturedIO(None, None)
+    assert cap.stdout == ""
+    assert cap.stderr == ""
+    assert cap.outputs == []
