Add __enter__ and __exit__ to JumpHandle (#862)

Signed-off-by: Shane Loretz <sloretz@openrobotics.org>

rclpy/rclpy/clock.py

@@ -108,6 +108,12 @@ def unregister(self):
                 self._clock.handle.remove_clock_callback(self)
             self._clock = None
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, t, v, tb):
+        self.unregister()
+
 
 class Clock:
 

rclpy/test/test_clock.py

@@ -19,6 +19,7 @@
 import pytest
 from rclpy.clock import Clock
 from rclpy.clock import ClockType
+from rclpy.clock import JumpHandle
 from rclpy.clock import JumpThreshold
 from rclpy.clock import ROSClock
 from rclpy.duration import Duration
@@ -208,3 +209,20 @@ def test_triggered_clock_change_callbacks(self):
         handler1.unregister()
         handler2.unregister()
         handler3.unregister()
+
+
+def test_with_jump_handle():
+    clock = ROSClock()
+    clock._set_ros_time_is_active(False)
+
+    post_callback = Mock()
+    threshold = JumpThreshold(min_forward=None, min_backward=None, on_clock_change=True)
+
+    with clock.create_jump_callback(threshold, post_callback=post_callback) as jump_handler:
+        assert isinstance(jump_handler, JumpHandle)
+        clock._set_ros_time_is_active(True)
+        post_callback.assert_called_once()
+
+    post_callback.reset_mock()
+    clock._set_ros_time_is_active(False)
+    post_callback.assert_not_called()