Refactor Capture classes

Moves {Passthrough,CaptureIO} to capture module.

Author: blueyed

src/_pytest/capture.py

@@ -11,12 +11,11 @@
 from tempfile import TemporaryFile
 from typing import BinaryIO
 from typing import Generator
+from typing import IO
 from typing import Iterable
 from typing import Optional
 
 import pytest
-from _pytest.compat import CaptureAndPassthroughIO
-from _pytest.compat import CaptureIO
 from _pytest.config import Config
 from _pytest.fixtures import FixtureRequest
 
@@ -98,7 +97,8 @@ def _getcapture(self, method):
             return MultiCapture(out=False, err=False, in_=False)
         elif method == "tee-sys":
             return MultiCapture(out=True, err=True, in_=False, Capture=TeeSysCapture)
-        raise ValueError("unknown capturing method: %r" % method)  # pragma: no cover
+        else:
+            assert False, "unknown capturing method: {}".format(method)
 
     def is_capturing(self):
         if self.is_globally_capturing():
@@ -323,6 +323,25 @@ def capfdbinary(request):
         yield fixture
 
 
+class CaptureIO(io.TextIOWrapper):
+    def __init__(self) -> None:
+        super().__init__(io.BytesIO(), encoding="UTF-8", newline="", write_through=True)
+
+    def getvalue(self) -> str:
+        assert isinstance(self.buffer, io.BytesIO)
+        return self.buffer.getvalue().decode("UTF-8")
+
+
+class PassthroughCaptureIO(CaptureIO):
+    def __init__(self, other: IO) -> None:
+        self._other = other
+        super().__init__()
+
+    def write(self, s) -> int:
+        super().write(s)
+        return self._other.write(s)
+
+
 class CaptureFixture:
     """
     Object returned by :py:func:`capsys`, :py:func:`capsysbinary`, :py:func:`capfd` and :py:func:`capfdbinary`
@@ -686,16 +705,13 @@ def snap(self):
 
 
 class TeeSysCapture(SysCapture):
-    def __init__(self, fd, tmpfile=None):
-        name = patchsysdict[fd]
-        self._old = getattr(sys, name)
-        self.name = name
-        if tmpfile is None:
-            if name == "stdin":
-                tmpfile = DontReadFromInput()
-            else:
-                tmpfile = CaptureAndPassthroughIO(self._old)
-        self.tmpfile = tmpfile
+    def __init__(self, fd: int) -> None:
+        old = getattr(sys, patchsysdict[fd])
+        if fd == 0:
+            super().__init__(fd)
+        else:
+            super().__init__(fd, PassthroughCaptureIO(old))
+        assert self._old == old, (self._old, old)
 
 
 map_fixname_class = {

src/_pytest/compat.py

@@ -3,7 +3,6 @@
 """
 import functools
 import inspect
-import io
 import os
 import re
 import sys
@@ -13,7 +12,6 @@
 from typing import Any
 from typing import Callable
 from typing import Generic
-from typing import IO
 from typing import Optional
 from typing import overload
 from typing import Tuple
@@ -360,25 +358,6 @@ def _setup_collect_fakemodule() -> None:
         setattr(pytest.collect, attr_name, getattr(pytest, attr_name))  # type: ignore
 
 
-class CaptureIO(io.TextIOWrapper):
-    def __init__(self) -> None:
-        super().__init__(io.BytesIO(), encoding="UTF-8", newline="", write_through=True)
-
-    def getvalue(self) -> str:
-        assert isinstance(self.buffer, io.BytesIO)
-        return self.buffer.getvalue().decode("UTF-8")
-
-
-class CaptureAndPassthroughIO(CaptureIO):
-    def __init__(self, other: IO) -> None:
-        self._other = other
-        super().__init__()
-
-    def write(self, s) -> int:
-        super().write(s)
-        return self._other.write(s)
-
-
 if sys.version_info < (3, 5, 2):
 
     def overload(f):  # noqa: F811

testing/test_capture.py

@@ -822,10 +822,10 @@ def test_write_bytes_to_buffer(self):
         assert f.getvalue() == "foo\r\n"
 
 
-class TestCaptureAndPassthroughIO(TestCaptureIO):
+class TestPassthroughCaptureIO(TestCaptureIO):
     def test_text(self):
         sio = io.StringIO()
-        f = capture.CaptureAndPassthroughIO(sio)
+        f = capture.PassthroughCaptureIO(sio)
         f.write("hello")
         s1 = f.getvalue()
         assert s1 == "hello"
@@ -836,7 +836,7 @@ def test_text(self):
 
     def test_unicode_and_str_mixture(self):
         sio = io.StringIO()
-        f = capture.CaptureAndPassthroughIO(sio)
+        f = capture.PassthroughCaptureIO(sio)
         f.write("\u00f6")
         pytest.raises(TypeError, f.write, b"hello")