losedows

Author: bitplane

src/bittty/pty/windows.py

@@ -31,8 +31,13 @@ def read(self, size: int = -1) -> bytes:
 
     def write(self, data: bytes) -> int:
         """Write bytes data."""
-        # winpty.write() actually expects bytes according to stub but error suggests strings
-        return self.pty.write(data)
+        # winpty.write() expects strings, not bytes
+        try:
+            return self.pty.write(data)
+        except TypeError:
+            # Fallback: convert bytes to string
+            text = data.decode("utf-8", errors="replace")
+            return self.pty.write(text)
 
     def close(self) -> None:
         """Close the PTY."""
@@ -113,7 +118,16 @@ def spawn_process(self, command: str, env: Optional[Dict[str, str]] = ENV) -> su
         if self.closed:
             raise OSError("PTY is closed")
 
-        self.pty.spawn(command, env=env)
+        # Convert env dict to winpty format: null-separated "KEY=VALUE" string
+        if env:
+            env_strs = []
+            for key, value in env.items():
+                env_strs.append(f"{key}={value}")
+            env_string = "\0".join(env_strs) + "\0"
+        else:
+            env_string = ""
+
+        self.pty.spawn(command, env=env_string)
 
         # Return a process-like object that provides compatibility with subprocess.Popen
         process = WinptyProcessWrapper(self.pty)

tests/unit/test_windows_env.py

@@ -0,0 +1,104 @@
+"""Test Windows PTY environment string formatting."""
+
+import pytest
+from unittest.mock import Mock, patch
+from bittty.pty.windows import WindowsPTY
+
+
+@pytest.mark.windows
+def test_env_dict_to_string_conversion():
+    """Test that env dict is converted to correct null-separated string format."""
+
+    # Mock winpty to avoid actual PTY creation
+    mock_winpty = Mock()
+    mock_pty = Mock()
+    mock_winpty.PTY.return_value = mock_pty
+
+    with patch("bittty.pty.windows.winpty", mock_winpty):
+        pty = WindowsPTY(24, 80)
+
+        # Test with env dict
+        test_env = {"PATH": "/bin", "USER": "test", "HOME": "/home/test"}
+
+        # Mock the spawn method to capture the env string
+        spawn_calls = []
+
+        def capture_spawn(command, env):
+            spawn_calls.append((command, env))
+
+        mock_pty.spawn = capture_spawn
+
+        pty.spawn_process("cmd.exe", env=test_env)
+
+        # Check the call was made
+        assert len(spawn_calls) == 1
+        command, env_string = spawn_calls[0]
+
+        assert command == "cmd.exe"
+
+        # Parse the env string back to verify format
+        env_parts = env_string.rstrip("\0").split("\0")
+        reconstructed_env = {}
+        for part in env_parts:
+            key, value = part.split("=", 1)
+            reconstructed_env[key] = value
+
+        assert reconstructed_env == test_env
+
+
+@pytest.mark.windows
+def test_empty_env_string():
+    """Test that empty/None env results in empty string."""
+
+    mock_winpty = Mock()
+    mock_pty = Mock()
+    mock_winpty.PTY.return_value = mock_pty
+
+    with patch("bittty.pty.windows.winpty", mock_winpty):
+        pty = WindowsPTY(24, 80)
+
+        spawn_calls = []
+
+        def capture_spawn(command, env):
+            spawn_calls.append((command, env))
+
+        mock_pty.spawn = capture_spawn
+
+        # Test with None env
+        pty.spawn_process("cmd.exe", env=None)
+
+        assert len(spawn_calls) == 1
+        command, env_string = spawn_calls[0]
+        assert command == "cmd.exe"
+        assert env_string == ""
+
+
+@pytest.mark.windows
+def test_env_with_special_chars():
+    """Test env vars with special characters are handled correctly."""
+
+    mock_winpty = Mock()
+    mock_pty = Mock()
+    mock_winpty.PTY.return_value = mock_pty
+
+    with patch("bittty.pty.windows.winpty", mock_winpty):
+        pty = WindowsPTY(24, 80)
+
+        spawn_calls = []
+
+        def capture_spawn(command, env):
+            spawn_calls.append((command, env))
+
+        mock_pty.spawn = capture_spawn
+
+        # Test with special chars
+        test_env = {"PATH": "C:\\Program Files;C:\\Windows", "TEMP": "C:\\Temp\\with spaces"}
+
+        pty.spawn_process("cmd.exe", env=test_env)
+
+        command, env_string = spawn_calls[0]
+
+        # Verify the string contains the expected format
+        assert "PATH=C:\\Program Files;C:\\Windows" in env_string
+        assert "TEMP=C:\\Temp\\with spaces" in env_string
+        assert env_string.endswith("\0")