launch_turtle.py

import unittest
import sys
import os

import pytest
import launch_testing
from launch import LaunchDescription
from launch.actions import ExecuteProcess
from launch_ros.actions import Node


ARTEFACTS_PARAMS_FILE = os.environ.get(
    "ARTEFACTS_SCENARIO_PARAMS_FILE", {}
)

@pytest.mark.launch_test
def generate_test_description():
    proc_env = os.environ.copy()
    proc_env['PYTHONUNBUFFERED'] = '1'
    # TODO switch to package
    sample_process = ExecuteProcess(
        cmd=[sys.executable, "sample_node.py"],
        output="log", env=proc_env)

    rosbag_cmd = ['ros2', 'bag', 'record', '-a']
    bag_recorder = ExecuteProcess(
        cmd=rosbag_cmd,
        output='screen', env=proc_env)
    return LaunchDescription([
        Node(
            package="turtlesim",
            executable='turtlesim_node',
            parameters=[ARTEFACTS_PARAMS_FILE],
        ),
        bag_recorder,
        sample_process,
        launch_testing.actions.ReadyToTest()
    ]), {"sample_process": sample_process}


class TestTurtle(unittest.TestCase):
    def test_tank_reach_target(self, proc_output, sample_process):
        # This will match stdout from test_process.
        proc_output.assertWaitFor("Turtle nearing right edge", timeout=5)