Add restore functionality to IF sessions

src/mudlib/if_session.py

@@ -109,6 +109,31 @@ class IFSession:
         confirmation = await self._read_response()
         return confirmation
 
+    async def _do_restore(self) -> str:
+        """Restore game state from disk. Returns game text or empty string."""
+        # Check if save file exists
+        if not self.save_path.exists():
+            return ""
+
+        if not self.process or not self.process.stdin:
+            return ""
+
+        # Send "restore" command to dfrotz
+        self.process.stdin.write(b"restore\n")
+        await self.process.stdin.drain()
+
+        # Read filename prompt
+        await self._read_response()
+
+        # Send save file path
+        save_path_str = str(self.save_path)
+        self.process.stdin.write(f"{save_path_str}\n".encode())
+        await self.process.stdin.drain()
+
+        # Read game text response
+        game_text = await self._read_response()
+        return game_text
+
     async def _read_response(self) -> str:
         """Read dfrotz output until the '>' prompt appears."""
         if not self.process or not self.process.stdout:

tests/test_if_session.py

@@ -410,3 +410,72 @@ async def test_do_save_creates_save_directory(tmp_path):
 
     # Now it should exist
     assert expected_dir.exists()
+
+
+@pytest.mark.asyncio
+async def test_do_restore_returns_empty_if_no_save(tmp_path):
+    """_do_restore() returns empty string if no save file exists."""
+    player = MagicMock()
+    player.name = "tester"
+    session = IFSession(player, "/path/to/zork.z5", "zork")
+    session._data_dir = tmp_path
+
+    # Mock process (even though we won't use it)
+    session.process = MagicMock()
+
+    # No save file exists
+    assert not session.save_path.exists()
+
+    result = await session._do_restore()
+
+    assert result == ""
+
+
+@pytest.mark.asyncio
+async def test_do_restore_sends_restore_command(tmp_path):
+    """_do_restore() sends restore command and filepath to dfrotz."""
+    player = MagicMock()
+    player.name = "tester"
+    session = IFSession(player, "/path/to/zork.z5", "zork")
+    session._data_dir = tmp_path
+
+    # Create a fake save file
+    session._ensure_save_dir()
+    session.save_path.write_text("fake save data")
+
+    # Mock process
+    mock_process = MagicMock()
+    mock_process.stdin = MagicMock()
+    mock_process.stdin.write = MagicMock()
+    mock_process.stdin.drain = AsyncMock()
+    mock_process.stdout = AsyncMock()
+    session.process = mock_process
+
+    # Simulate dfrotz responses: filename prompt, then game text
+    responses = [
+        b"Enter saved game to load: \n>",
+        b"West of House\nYou are standing in an open field.\n>",
+    ]
+    response_data = b"".join(responses)
+
+    async def read_side_effect(n):
+        nonlocal response_data
+        if response_data:
+            byte = response_data[:1]
+            response_data = response_data[1:]
+            return byte
+        return b""
+
+    mock_process.stdout.read = AsyncMock(side_effect=read_side_effect)
+
+    result = await session._do_restore()
+
+    # Should have written "restore\n" then the filepath
+    calls = mock_process.stdin.write.call_args_list
+    assert len(calls) == 2
+    assert calls[0][0][0] == b"restore\n"
+    assert str(session.save_path) in calls[1][0][0].decode()
+
+    # Result should contain game text
+    assert "West of House" in result
+    assert "open field" in result