feat(driver): add W3C actions helper and Driver.swipe_path

tests/fakes.py

@@ -64,6 +64,11 @@ class FakeDriver(Driver):
     ) -> None:
         self.calls.append(("swipe", (start_x, start_y, end_x, end_y, duration_ms)))
 
+    def swipe_path(
+        self, waypoints: list[tuple[float, float]], duration_ms: int
+    ) -> None:
+        self.calls.append(("swipe_path", (tuple(waypoints), duration_ms)))
+
     def input(self, text: str) -> None:
         self.calls.append(("input", (text,)))
 

tests/test_android_driver.py

@@ -104,6 +104,7 @@ def test_connect_failure_raises_device_offline_and_clears_client() -> None:
         ("unlock", {}),
         ("disconnect", {}),
         ("long_press", {"x": 1, "y": 2}),
+        ("swipe_path", {"waypoints": [(0, 0), (1, 1)], "duration_ms": 100}),
     ],
 )
 def test_operation_before_connect_raises_device_offline(
@@ -229,6 +230,23 @@ def test_home_uses_presskey_with_home_keycode() -> None:
     )
 
 
+def test_swipe_path_sends_w3c_actions() -> None:
+    from driver._w3c_actions import build_swipe_actions
+
+    driver = _connected_driver()
+    waypoints = [(0, 0), (50, 5), (100, 0)]
+    driver.swipe_path(waypoints, 600)
+    args = driver._client.execute.call_args.args
+    assert args[1] == {"actions": build_swipe_actions(waypoints, 600)}
+
+
+def test_swipe_path_wraps_exception_into_driver_error() -> None:
+    driver = _connected_driver()
+    driver._client.execute.side_effect = RuntimeError("boom")
+    with pytest.raises(DriverError):
+        driver.swipe_path([(0, 0), (1, 1)], 100)
+
+
 def test_swipe_uses_drag_gesture_with_converted_speed() -> None:
     driver = _connected_driver()
     # 100px horizontal drag over 100ms => 100 / 0.1 = 1000 px/s

tests/test_describe_screen.py

@@ -46,6 +46,11 @@ class TreeFailingDriver(Driver):
     ) -> None:
         return None
 
+    def swipe_path(
+        self, waypoints: list[tuple[float, float]], duration_ms: int
+    ) -> None:
+        return None
+
     def input(self, text: str) -> None:
         return None
 

tests/test_w3c_actions.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import pytest
+
+from driver._w3c_actions import (
+    build_double_tap_actions,
+    build_swipe_actions,
+)
+
+
+def test_build_swipe_actions_shape_and_duration_split():
+    actions = build_swipe_actions([(0, 0), (50, 10), (100, 0)], 600)
+    assert len(actions) == 1
+    pointer = actions[0]
+    assert pointer["type"] == "pointer"
+    assert pointer["id"] == "finger1"
+    assert pointer["parameters"]["pointerType"] == "touch"
+    seq = pointer["actions"]
+    types = [a["type"] for a in seq]
+    assert types == [
+        "pointerMove",
+        "pointerDown",
+        "pointerMove",
+        "pointerMove",
+        "pointerUp",
+    ]
+    # 600ms over 2 segments => 300ms per move after pointerDown
+    moves_after_down = [a for a in seq if a["type"] == "pointerMove"][1:]
+    assert all(m["duration"] == 300 for m in moves_after_down)
+    assert seq[0]["x"] == 0 and seq[0]["y"] == 0
+    assert seq[-1]["x"] == 100 and seq[-1]["y"] == 0
+
+
+def test_build_swipe_actions_requires_two_waypoints():
+    with pytest.raises(ValueError):
+        build_swipe_actions([(1, 1)], 100)
+
+
+def test_build_double_tap_actions_shape():
+    actions = build_double_tap_actions(10, 20, interval_ms=80)
+    seq = actions[0]["actions"]
+    types = [a["type"] for a in seq]
+    assert types == [
+        "pointerMove",
+        "pointerDown",
+        "pointerUp",
+        "pause",
+        "pointerDown",
+        "pointerUp",
+    ]
+    pause = next(a for a in seq if a["type"] == "pause")
+    assert pause["duration"] == 80
+    assert seq[0]["x"] == 10 and seq[0]["y"] == 20