Parse YAML respawn delay strings

launch/launch/actions/execute_process.py

@@ -370,6 +370,15 @@ def parse(
         if 'respawn_delay' not in ignore:
             respawn_delay = entity.get_attr('respawn_delay', data_type=float, optional=True)
             if respawn_delay is not None:
+                if isinstance(respawn_delay, str):
+                    try:
+                        respawn_delay = float(respawn_delay)
+                    except ValueError:
+                        raise ValueError(
+                            'Attribute respawn_delay of Entity node expected to be '
+                            'a non-negative floating-point value but got `{}`'.format(
+                                respawn_delay)
+                        ) from None
                 if respawn_delay < 0.0:
                     raise ValueError(
                         'Attribute respawn_delay of Entity node expected to be '

launch_yaml/test/launch_yaml/test_executable.py

@@ -19,8 +19,10 @@
 
 from launch import LaunchService
 from launch.actions import Shutdown
+from launch.actions.execute_process import ExecuteProcess
 
 from parser_no_extensions import load_no_extensions
+import pytest
 
 
 def test_executable():
@@ -82,5 +84,37 @@ def test_executable_on_exit():
     assert isinstance(sub_entities[0], Shutdown)
 
 
+def test_executable_respawn_delay_string():
+    yaml_file = textwrap.dedent(
+        """
+        launch:
+        -   executable:
+                cmd: echo test
+                respawn_delay: '2.0'
+        """
+    )
+    root_entity, parser = load_no_extensions(io.StringIO(yaml_file))
+
+    _, kwargs = ExecuteProcess.parse(root_entity.children[0], parser)
+
+    assert kwargs['respawn_delay'] == 2.0
+    assert isinstance(kwargs['respawn_delay'], float)
+
+
+def test_executable_respawn_delay_invalid_string():
+    yaml_file = textwrap.dedent(
+        """
+        launch:
+        -   executable:
+                cmd: echo test
+                respawn_delay: ''
+        """
+    )
+    root_entity, parser = load_no_extensions(io.StringIO(yaml_file))
+
+    with pytest.raises(ValueError, match='respawn_delay'):
+        ExecuteProcess.parse(root_entity.children[0], parser)
+
+
 if __name__ == '__main__':
     test_executable()