Add a PTY fallback for Windows in tests

magicbus/test/__init__.py

@@ -5,7 +5,7 @@
 
 from magicbus.compat import HTTPServer, HTTPConnection, HTTPHandler
 import os
-from subprocess import Popen
+from subprocess import DEVNULL, Popen
 import threading
 import time
 
@@ -30,20 +30,21 @@ def start(self):
         cwd = os.path.abspath(os.path.join(os.path.dirname(__file__), '../..'))
         env = os.environ.copy()
         env['PYTHONPATH'] = cwd
-        popen_kwargs = {}
         # NOTE: Openning a pseudo-terminal to interact with subprocess
         # NOTE: is necessary because `pytest` captures stdin unless `-s`
         # NOTE: is used and it's impossible to disable this with
         # NOTE: `capsys` because it only unpatches stdout+stderr but not
         # NOTE: stdin.
-        if pty is not None:  # NOTE: It's probably Windows
+        if pty is not None:  # NOTE: Something UNIXy
             master_fd, self._pty_stdin = pty.openpty()
             popen_kwargs = {
                 # Ref: https://stackoverflow.com/a/43012138/595220
                 'preexec_fn': os.setsid, 'stdin': self._pty_stdin,
                 # stdout and stderr are both needed for TTY
                 'stdout': master_fd, 'stderr': master_fd,
             }
+        else:  # NOTE: It's probably Windows
+            popen_kwargs = {'stdin': DEVNULL}
         self.process = Popen(self.args, env=env, **popen_kwargs)
         if pty is not None:
             os.close(master_fd)  # Only needed to spawn the process