capture: revisit/fix __repr__, define _in_suspended (#6749)

src/_pytest/capture.py

@@ -438,6 +438,7 @@ CaptureResult = collections.namedtuple("CaptureResult", ["out", "err"])
 class MultiCapture:
     out = err = in_ = None
     _state = None
+    _in_suspended = False
 
     def __init__(self, out=True, err=True, in_=True, Capture=None):
         if in_:
@@ -449,11 +450,7 @@ class MultiCapture:
 
     def __repr__(self):
         return "<MultiCapture out={!r} err={!r} in_={!r} _state={!r} _in_suspended={!r}>".format(
-            self.out,
-            self.err,
-            self.in_,
-            self._state,
-            getattr(self, "_in_suspended", "<UNSET>"),
+            self.out, self.err, self.in_, self._state, self._in_suspended,
         )
 
     def start_capturing(self):
@@ -490,9 +487,9 @@ class MultiCapture:
             self.out.resume()
         if self.err:
             self.err.resume()
-        if hasattr(self, "_in_suspended"):
+        if self._in_suspended:
             self.in_.resume()
-            del self._in_suspended
+            self._in_suspended = False
 
     def stop_capturing(self):
         """ stop capturing and reset capturing streams """
@@ -555,8 +552,12 @@ class FDCaptureBinary:
             self.tmpfile_fd = tmpfile.fileno()
 
     def __repr__(self):
-        return "<FDCapture {} oldfd={} _state={!r}>".format(
-            self.targetfd, getattr(self, "targetfd_save", None), self._state
+        return "<{} {} oldfd={} _state={!r} tmpfile={}>".format(
+            self.__class__.__name__,
+            self.targetfd,
+            getattr(self, "targetfd_save", "<UNSET>"),
+            self._state,
+            hasattr(self, "tmpfile") and repr(self.tmpfile) or "<UNSET>",
         )
 
     def _start(self):
@@ -637,8 +638,12 @@ class SysCapture:
         self.tmpfile = tmpfile
 
     def __repr__(self):
-        return "<SysCapture {} _old={!r}, tmpfile={!r} _state={!r}>".format(
-            self.name, self._old, self.tmpfile, self._state
+        return "<{} {} _old={} _state={!r} tmpfile={!r}>".format(
+            self.__class__.__name__,
+            self.name,
+            hasattr(self, "_old") and repr(self._old) or "<UNSET>",
+            self._state,
+            self.tmpfile,
         )
 
     def start(self):

testing/test_capture.py

@@ -1005,6 +1005,18 @@ class TestFDCapture:
             cap.done()
             pytest.raises(AttributeError, cap.suspend)
 
+            assert repr(cap) == (
+                "<FDCapture 1 oldfd=<UNSET> _state='done' tmpfile={!r}>".format(
+                    cap.tmpfile
+                )
+            )
+            # Should not crash with missing "_old".
+            assert repr(cap.syscapture) == (
+                "<SysCapture stdout _old=<UNSET> _state='done' tmpfile={!r}>".format(
+                    cap.syscapture.tmpfile
+                )
+            )
+
     def test_capfd_sys_stdout_mode(self, capfd):
         assert "b" not in sys.stdout.mode
 
@@ -1212,19 +1224,19 @@ class TestStdCaptureFDinvalidFD:
             def test_stdout():
                 os.close(1)
                 cap = StdCaptureFD(out=True, err=False, in_=False)
-                assert repr(cap.out) == "<FDCapture 1 oldfd=None _state=None>"
+                assert repr(cap.out) == "<FDCapture 1 oldfd=<UNSET> _state=None tmpfile=<UNSET>>"
                 cap.stop_capturing()
 
             def test_stderr():
                 os.close(2)
                 cap = StdCaptureFD(out=False, err=True, in_=False)
-                assert repr(cap.err) == "<FDCapture 2 oldfd=None _state=None>"
+                assert repr(cap.err) == "<FDCapture 2 oldfd=<UNSET> _state=None tmpfile=<UNSET>>"
                 cap.stop_capturing()
 
             def test_stdin():
                 os.close(0)
                 cap = StdCaptureFD(out=False, err=False, in_=True)
-                assert repr(cap.in_) == "<FDCapture 0 oldfd=None _state=None>"
+                assert repr(cap.in_) == "<FDCapture 0 oldfd=<UNSET> _state=None tmpfile=<UNSET>>"
                 cap.stop_capturing()
         """
         )