Fix the unit test for humble compatibilty

Author: emersonknapp

test/launch/basic_launch.py

@@ -13,25 +13,11 @@
 # limitations under the License.
 
 from launch_frontend_py import launch
-from launch_frontend_py.actions import arg, log
+from launch_frontend_py.actions import arg, executable
 
 
 def generate_launch_description():
     return launch([
-        arg(name='foo', default='bar'),
-        log(
-            level='INFO',
-            message='I am a launch file: foo=$(var foo)',
-        ),
-        # TODO(emerson) make if_ work
-        # log(
-        #     if_='$(var foo)',
-        #     level='INFO',
-        #     message='This conditional log only happened because foo is true',
-        # ),
-        # log(
-        #     if_='$(not $(var foo))',
-        #     level='INFO',
-        #     message='This conditional log only happened because foo is false',
-        # ),
+        arg(name='message', default='hello world'),
+        executable(cmd='echo $(var message)', output='both'),
     ])

test/test_frontend.py

@@ -15,31 +15,34 @@
 from pathlib import Path
 
 from launch import LaunchContext, LaunchDescription
-from launch.actions import DeclareLaunchArgument, IncludeLaunchDescription, Log
-from launch.utilities import perform_substitutions
+from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
 
 THIS_DIR = Path(__file__).parent
 
 
 def test_load_basic():
     context = LaunchContext()
 
-    include = IncludeLaunchDescription(THIS_DIR / 'launch' / 'basic_launch.py')
+    include = IncludeLaunchDescription(str(THIS_DIR / 'launch' / 'basic_launch.py'))
+    print(include)
     included_entities = include.get_sub_entities()
+    print(included_entities)
+    assert len(included_entities) == 1
+
     launch_desc = included_entities[0]
     assert isinstance(launch_desc, LaunchDescription)
 
     launchfile_entities = launch_desc.describe_sub_entities()
     assert len(launchfile_entities) == 2
 
+    # The first entity is a declare()
     should_be_declare = launchfile_entities[0]
-    should_be_log = launchfile_entities[1]
-
     assert isinstance(should_be_declare, DeclareLaunchArgument)
     should_be_declare.visit(context)
 
-    assert isinstance(should_be_log, Log)
-    should_be_log.visit(context)
+    # Second is executable()
+    should_be_exec = launchfile_entities[1]
+    assert isinstance(should_be_exec, ExecuteProcess)
 
-    msg = perform_substitutions(context, should_be_log.msg)
-    assert msg == 'I am a launch file: foo=bar'
+    should_be_exec.prepare(context)
+    assert should_be_exec.process_description.final_cmd == ['echo', 'hello world']