Add a unit test for an actual loaded launchfile (#11)

Author: emersonknapp

package.xml

@@ -2,7 +2,7 @@
 <?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
 <package format="3">
   <name>launch_frontend_py</name>
-  <version>0.1.0</version>
+  <version>0.0.0</version>
   <description>Python frontend for writing ROS 2 launch files</description>
   <maintainer email="[email protected]">Emerson Knapp</maintainer>
   <license>Apache License 2.0</license>

test/include_launch.py test/launch/basic_launch.pytest/include_launch.py renamed to 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'),
-        log(
-            level='INFO',
-            message='I am an included 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/basic_launch.py test/launch/include_launch.pytest/basic_launch.py renamed to test/launch/include_launch.py

@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 from pathlib import Path
 
 from launch_frontend_py import launch

test/test_frontend.py

@@ -0,0 +1,49 @@
+# Copyright 2025 Polymath Robotics, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from pathlib import Path
+
+from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
+from launch.launch_context import LaunchContext
+from launch.launch_description import LaunchDescription
+
+THIS_DIR = Path(__file__).parent
+
+
+def test_load_basic():
+    context = LaunchContext()
+
+    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]
+    assert isinstance(should_be_declare, DeclareLaunchArgument)
+    should_be_declare.visit(context)
+
+    # Second is executable()
+    should_be_exec = launchfile_entities[1]
+    assert isinstance(should_be_exec, ExecuteProcess)
+
+    should_be_exec.prepare(context)
+    assert should_be_exec.process_description.final_cmd == ['echo', 'hello world']