CMR Tests Utils

A header only library to facilitate writing gtest unit tests for ROS2 nodes.

Table of Contents

• General Info
• Features
• Setup
• Usage
• Room for Improvement
• Contact
• License

General Information

The library provides an easy templated API for testing basic communication nodes in the ROS2 ecosystem. It also provide spinner classes to implement a threaded spin_some call in a tight, safe loop checking rclcpp::ok(). The project intents to help checking communication between nodes that implements services, actions, publishers and subscribers. Spinners can be use to emmulate running all nodes in different threads, cancelling the spin of one or all nodes registered etc...

Features

List the ready features here:

Asynchronous Communication

• Basic Subscriber
• Basic Publisher

Synchronous Communication

• Basic Service Client
• Basic Action Client
• Basic Action Server
• Basic Service Server

Spinners

• Single Threaded Spinner - calls spin_some for all nodes registered in one different thread.
• Multi Threaded Spinner - calls spin_some for groups. Implements multiple instances of SingleThreadSpinner

Robots

• SimulatedDifferentialRobot

Setup

The project requires set(CMAKE_CXX_STANDARD 20) in your CMakeLists.txt to be built. To setup the library in your ROS2 project:

• Create your test folder in your project root.
• Add the following lines to your project CMakeLists.txt:

if(BUILD_TESTING)
  find_package(ament_cmake_gtest REQUIRED)
  find_package(ament_cmake_pytest REQUIRED)
  add_subdirectory(test)
endif()

• Create your gtest cpp files in your test folder.
• Create a CMakeLists.txt in your test folder as following:

set(dependencies
  ${dependencies}
  ${cmr_tests_utils}
)

find_package(cmr_tests_utils REQUIRED)

ament_add_gtest(name_of_your_test name_of_your_test.cpp)
target_link_libraries(name_of_your_test
  name_of_the_libs_you_want_to_link
)
ament_target_dependencies(name_of_your_test ${dependencies})
target_include_directories(name_of_your_test PRIVATE "../include" "include" ${cmr_tests_utils_INCLUDE_DIRS})

Usage

A Simple Pub/Sub Test

rclcpp::init(0, nullptr);
auto spinner = cmr_tests_utils::SingleThreadSpinner();
auto sub_node = std::make_shared<cmr_tests_utils::BasicSubscriberNodeTest<std_msgs::msg::Int32>>("sub_test_node", "test_topic");
auto pub_node = std::make_shared<cmr_tests_utils::BasicPublisherNodeTest<std_msgs::msg::Int32>>("pub_test_node", "test_topic", false, 100);

EXPECT_FALSE(sub_node->has_data_been_received());

spinner.add_node(sub_node->get_node_base_interface());
spinner.add_node(pub_node->get_node_base_interface());

// Publish Data without Spinning
std_msgs::msg::Int32 msg;
msg.data = 42;
pub_node->publish(msg);

// Subscriber shouldn't have received anything
EXPECT_FALSE(sub_node->has_data_been_received());

// Spin both nodes
spinner.spin_some_all_nodes();
// Overhead for queued data population
std::this_thread::sleep_for(std::chrono::milliseconds(30));

EXPECT_TRUE(sub_node->has_data_been_received());
EXPECT_EQ(sub_node->get_received_msg().data, 42);

// Publish a message when both nodes are spinning
msg.data = 1337;
pub_node->publish(msg);
// Overhead for queued data population
std::this_thread::sleep_for(std::chrono::milliseconds(30));

EXPECT_EQ(sub_node->get_received_msg().data, 1337);

rclcpp::shutdown();

Room for Improvement

Room for improvement:

• Integrate a Setup/Teardown Fixture for rclcpp::init and rclcpp::shutdown

To do:

• CodeCov and CodeFactor integration.

License

This project is open source and available under the Apache License, Version 2.0.