test: add console hotkey tests using PTY-simulated stdin

- Ctrl-B x3 exits cleanly
- Ctrl-] x3 triggers on_power_cycle and console stays alive
- Ctrl-] x3 without a power client does nothing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: evakhoni

python/packages/jumpstarter-driver-pyserial/jumpstarter_driver_pyserial/client_test.py

@@ -0,0 +1,32 @@
+import threading
+from unittest.mock import MagicMock
+
+from .driver import PySerial
+from jumpstarter.common.utils import serve
+
+
+def test_find_power_client_no_root():
+    with serve(PySerial(url="loop://")) as client:
+        assert client._find_power_client() is None
+
+
+def test_find_power_client_with_cycle():
+    power = MagicMock(spec=["cycle", "children"])
+    power.children = {}
+    root = MagicMock(spec=["children"])
+    root.children = {"power": power}
+
+    with serve(PySerial(url="loop://")) as client:
+        object.__setattr__(client, "root", root)
+        assert client._find_power_client() is power
+
+
+def test_make_power_cycle_calls_cycle():
+    called = threading.Event()
+    power = MagicMock()
+    power.cycle = MagicMock(side_effect=lambda: called.set())
+
+    with serve(PySerial(url="loop://")) as client:
+        cycle_fn = client._make_power_cycle(power)
+        client.portal.call(cycle_fn)
+        assert called.is_set()

python/packages/jumpstarter-driver-pyserial/jumpstarter_driver_pyserial/console_test.py

@@ -0,0 +1,91 @@
+import os
+import threading
+import time
+from unittest.mock import MagicMock, patch
+
+from .console import Console
+from .driver import PySerial
+from jumpstarter.common.utils import serve
+
+
+def _start_console(client, on_power_cycle=None):
+    """Run Console.run() in a thread with a PTY substituted for stdin.
+
+    Returns (master_fd, thread, result_dict). Write keypresses to master_fd;
+    the result dict gets an 'exc' key if the console thread raises.
+    """
+    master_fd, slave_fd = os.openpty()
+    slave_file = os.fdopen(slave_fd, "rb", buffering=0)
+
+    mock_stdin = MagicMock()
+    mock_stdin.fileno.return_value = slave_fd
+    mock_stdin.buffer = slave_file
+
+    result = {}
+
+    def _run():
+        with patch("sys.stdin", mock_stdin):
+            console = Console(serial_client=client, on_power_cycle=on_power_cycle)
+            try:
+                console.run()
+            except Exception as e:
+                result["exc"] = e
+        slave_file.close()
+
+    t = threading.Thread(target=_run, daemon=True)
+    t.start()
+    return master_fd, t, result
+
+
+def test_ctrl_b_exits():
+    with serve(PySerial(url="loop://")) as client:
+        master_fd, t, result = _start_console(client)
+        try:
+            time.sleep(0.1)
+            os.write(master_fd, b"a")
+            os.write(master_fd, b"\x02\x02\x02")
+            t.join(timeout=5)
+        finally:
+            os.close(master_fd)
+
+    assert not t.is_alive(), "console did not exit after Ctrl-B x3"
+    assert "exc" not in result
+
+
+def test_ctrl_bracket_triggers_power_cycle():
+    power_cycled = threading.Event()
+
+    async def on_power_cycle():
+        power_cycled.set()
+
+    with serve(PySerial(url="loop://")) as client:
+        master_fd, t, result = _start_console(client, on_power_cycle=on_power_cycle)
+        try:
+            time.sleep(0.1)
+            os.write(master_fd, b"\x1d\x1d\x1d")
+            assert power_cycled.wait(timeout=5), "power cycle was not triggered"
+            assert t.is_alive(), "console exited after power cycle"
+            os.write(master_fd, b"\x02\x02\x02")
+            t.join(timeout=5)
+        finally:
+            os.close(master_fd)
+
+    assert not t.is_alive()
+    assert "exc" not in result
+
+
+def test_ctrl_bracket_without_power_client():
+    with serve(PySerial(url="loop://")) as client:
+        master_fd, t, result = _start_console(client, on_power_cycle=None)
+        try:
+            time.sleep(0.1)
+            os.write(master_fd, b"\x1d\x1d\x1d")
+            time.sleep(0.1)
+            assert t.is_alive(), "console exited unexpectedly on Ctrl-] without power client"
+            os.write(master_fd, b"\x02\x02\x02")
+            t.join(timeout=5)
+        finally:
+            os.close(master_fd)
+
+    assert not t.is_alive()
+    assert "exc" not in result