ROS2 Testing

Keep domain logic free of ROS dependencies so it can be tested as pure Python with pytest. For node-level tests, use pytest fixtures that call rclpy.init and rclpy.shutdown, then create helper nodes to publish and subscribe to topics.

Define interfaces for repositories or services in the domain layer, then create mock classes with gmock MOCK_METHOD macros. Inject the mock into your use case and set expectations with EXPECT_CALL and WillOnce(Return(...)).

Integration tests instantiate individual nodes or components and verify their topic behavior in isolation. Launch tests use launch_testing to start the full system and run assertions or GTest executables against the running application.

Yes, add the GTest executable as a Node action in the launch description alongside the system under test, and include ReadyToTest from launch_testing.actions. This enables system-level verification within a standard launch test.

Separating domain logic from rclpy or rclcpp dependencies lets unit tests run without initializing a ROS context, making them fast and deterministic. ROS-dependent code is then covered separately by integration and launch tests.

Use rclcpp::spin_some or wait_for_future inside the test body to process callbacks and futures. Initialize the context in SetUp with rclcpp::init and shut it down in TearDown to keep tests isolated.