Hermes-agent

tests/hermes_cli/test_web_server_pty_import.py

@@ -0,0 +1,83 @@
+"""Test the platform-branched PTY bridge import in hermes_cli.web_server.
+
+The /api/pty WebSocket handler in web_server.py picks its bridge at import
+time via ``sys.platform.startswith("win")`` — Windows gets the ConPTY
+backend, POSIX gets the fcntl/termios one.  Both branches must:
+
+  1. Expose ``PtyBridge`` as the bridge class (or None) and
+     ``PtyUnavailableError`` as an exception class.
+  2. Set ``_PTY_BRIDGE_AVAILABLE`` correctly.
+  3. Never raise at import time when the platform-native dependency is
+     missing — the dashboard's non-chat tabs must keep loading.
+
+This test asserts the live state on whichever platform CI runs on, plus a
+source-text check confirming the branch shape is preserved so a future
+refactor can't accidentally collapse it back to a POSIX-only import.
+"""
+
+from __future__ import annotations
+
+import sys
+
+import pytest
+
+from hermes_cli import web_server
+
+
+def test_web_server_exposes_pty_bridge_symbols():
+    """The two symbols /api/pty consumes must always exist."""
+    assert hasattr(web_server, "PtyBridge")
+    assert hasattr(web_server, "PtyUnavailableError")
+    assert hasattr(web_server, "_PTY_BRIDGE_AVAILABLE")
+    # PtyUnavailableError is always an exception class — either the real
+    # one from the platform bridge, or the local fallback class.
+    assert isinstance(web_server.PtyUnavailableError, type)
+    assert issubclass(web_server.PtyUnavailableError, BaseException)
+
+
+@pytest.mark.skipif(not sys.platform.startswith("win"), reason="Windows-only")
+def test_web_server_uses_win_pty_bridge_on_windows():
+    """On native Windows, web_server.PtyBridge must be the ConPTY backend."""
+    from hermes_cli.win_pty_bridge import WinPtyBridge
+
+    assert web_server.PtyBridge is WinPtyBridge
+    assert web_server._PTY_BRIDGE_AVAILABLE is True
+    # And the error class must be the one from the same module so isinstance
+    # checks in /api/pty's spawn fallback path actually work.
+    from hermes_cli.win_pty_bridge import PtyUnavailableError as WinErr
+
+    assert web_server.PtyUnavailableError is WinErr
+
+
+@pytest.mark.skipif(sys.platform.startswith("win"), reason="POSIX-only")
+def test_web_server_uses_posix_pty_bridge_on_posix():
+    """On POSIX, the bridge must be the fcntl/termios PtyBridge."""
+    from hermes_cli.pty_bridge import PtyBridge as PosixBridge
+    from hermes_cli.pty_bridge import PtyUnavailableError as PosixErr
+
+    assert web_server.PtyBridge is PosixBridge
+    assert web_server._PTY_BRIDGE_AVAILABLE is True
+    assert web_server.PtyUnavailableError is PosixErr
+
+
+def test_pty_bridge_import_block_is_platform_branched():
+    """Source-level guard: a future refactor must not collapse the branch
+    back to a single POSIX import.  Reads web_server.py directly so this
+    fails the same way on every OS — the runtime symbol checks above can
+    pass even when the branch shape is wrong on the current platform."""
+    src = pytest.importorskip("inspect").getsource(web_server)
+    # The shape we expect (from PR #39913):
+    #
+    #   if sys.platform.startswith("win"):
+    #       try:
+    #           from hermes_cli.win_pty_bridge import WinPtyBridge as PtyBridge, ...
+    #       except ImportError:
+    #           PtyBridge = None
+    #           ...
+    #   else:
+    #       try:
+    #           from hermes_cli.pty_bridge import PtyBridge, PtyUnavailableError
+    #       ...
+    assert 'sys.platform.startswith("win")' in src or "sys.platform.startswith('win')" in src
+    assert "from hermes_cli.win_pty_bridge import" in src
+    assert "from hermes_cli.pty_bridge import" in src