[WIP] Investigating/fixing capsysbin

src/_pytest/capture.py

@@ -2,7 +2,6 @@
 per-test stdout/stderr capturing mechanism.
 
 """
-import collections
 import contextlib
 import io
 import os
@@ -12,7 +11,9 @@
 from typing import BinaryIO
 from typing import Generator
 from typing import Iterable
+from typing import NamedTuple
 from typing import Optional
+from typing import Union
 
 import pytest
 from _pytest.compat import CaptureAndPassthroughIO
@@ -439,7 +440,11 @@ def __getattr__(self, name):
         return getattr(object.__getattribute__(self, "buffer"), name)
 
 
-CaptureResult = collections.namedtuple("CaptureResult", ["out", "err"])
+# XXX: Generic[AnyStr], and AnyStr as type directly does not work?
+#      Would be good to ensure out and err are of the same type.
+class CaptureResult(NamedTuple):
+    out: Union[str, bytes]
+    err: Union[str, bytes]
 
 
 class MultiCapture:

testing/test_capture.py

@@ -16,6 +16,7 @@
 from _pytest import capture
 from _pytest.capture import _get_multicapture
 from _pytest.capture import CaptureManager
+from _pytest.capture import CaptureResult
 from _pytest.capture import MultiCapture
 from _pytest.config import ExitCode
 
@@ -40,6 +41,27 @@ def TeeStdCapture(out=True, err=True, in_=True):
     return capture.MultiCapture(out, err, in_, Capture=capture.TeeSysCapture)
 
 
+def test_CaptureResult() -> None:
+    with pytest.raises(TypeError):
+        CaptureResult()  # type: ignore
+
+    cr = CaptureResult(out="out", err="err")
+    repr_ = repr(cr)
+    assert repr_ == "CaptureResult(out='out', err='err')"
+    assert str(cr) == repr_
+
+    cr = CaptureResult(out=b"out\nout2", err=b"err\nerr2")
+    repr_ = repr(cr)
+    assert repr_ == r"CaptureResult(out=b'out\nout2', err=b'err\nerr2')"
+    assert str(cr) == repr_
+
+    # XXX: should cause mypy type error?!
+    cr = CaptureResult(out="out", err=b"err")
+    repr_ = repr(cr)
+    assert repr_ == r"CaptureResult(out='out', err=b'err')"
+    assert str(cr) == repr_
+
+
 class TestCaptureManager:
     def test_getmethod_default_no_fd(self, monkeypatch):
         from _pytest.capture import pytest_addoption