Use constant definitions for testing special values

Inside the tests there exist special values to simulate an error in the hardware.
These magic numbers were used and defined at different places. This creates
one common place to define those. This should make maintenance more stable
and the tests easier to understand for new developers.

controller_manager/test/test_controller_manager_hardware_error_handling.cpp

@@ -21,6 +21,7 @@
 #include "controller_manager/controller_manager.hpp"
 #include "controller_manager_test_common.hpp"
 #include "hardware_interface/types/lifecycle_state_names.hpp"
+#include "hardware_interface/types/test_hardware_interface_constants.hpp"
 #include "lifecycle_msgs/msg/state.hpp"
 #include "test_controller/test_controller.hpp"
 
@@ -162,10 +163,6 @@ class TestControllerManagerWithTestableCM
       {}, strictness);
   }
 
-  // values to set to hardware to simulate failure on read and write
-  static constexpr double READ_FAIL_VALUE = 28282828.0;
-  static constexpr double WRITE_FAIL_VALUE = 23232323.0;
-
   static constexpr char TEST_CONTROLLER_ACTUATOR_NAME[] = "test_controller_actuator";
   static constexpr char TEST_CONTROLLER_SYSTEM_NAME[] = "test_controller_system";
   static constexpr char TEST_BROADCASTER_ALL_NAME[] = "test_broadcaster_all";
@@ -258,7 +255,8 @@ TEST_P(TestControllerManagerWithTestableCM, stop_controllers_on_hardware_read_er
 
   // Simulate error in read() on TEST_ACTUATOR_HARDWARE_NAME by setting first command interface to
   // READ_FAIL_VALUE
-  test_controller_actuator->set_first_command_interface_value_to = READ_FAIL_VALUE;
+  test_controller_actuator->set_first_command_interface_value_to =
+    hardware_interface::testing_constants::READ_FAIL_VALUE;
   {
     auto new_counter = test_controller_actuator->internal_counter + 1;
     EXPECT_EQ(controller_interface::return_type::OK, cm_->update(TIME, PERIOD));
@@ -327,8 +325,10 @@ TEST_P(TestControllerManagerWithTestableCM, stop_controllers_on_hardware_read_er
 
   // Simulate error in read() on TEST_ACTUATOR_HARDWARE_NAME and TEST_SYSTEM_HARDWARE_NAME
   // by setting first command interface to READ_FAIL_VALUE
-  test_controller_actuator->set_first_command_interface_value_to = READ_FAIL_VALUE;
-  test_controller_system->set_first_command_interface_value_to = READ_FAIL_VALUE;
+  test_controller_actuator->set_first_command_interface_value_to =
+    hardware_interface::testing_constants::READ_FAIL_VALUE;
+  test_controller_system->set_first_command_interface_value_to =
+    hardware_interface::testing_constants::READ_FAIL_VALUE;
   {
     auto previous_counter_lower = test_controller_actuator->internal_counter + 1;
     auto previous_counter_higher = test_controller_system->internal_counter + 1;
@@ -450,7 +450,8 @@ TEST_P(TestControllerManagerWithTestableCM, stop_controllers_on_hardware_write_e
 
   // Simulate error in write() on TEST_ACTUATOR_HARDWARE_NAME by setting first command interface to
   // WRITE_FAIL_VALUE
-  test_controller_actuator->set_first_command_interface_value_to = WRITE_FAIL_VALUE;
+  test_controller_actuator->set_first_command_interface_value_to =
+    hardware_interface::testing_constants::WRITE_FAIL_VALUE;
   {
     auto new_counter = test_controller_actuator->internal_counter + 1;
     EXPECT_EQ(controller_interface::return_type::OK, cm_->update(TIME, PERIOD));
@@ -519,8 +520,10 @@ TEST_P(TestControllerManagerWithTestableCM, stop_controllers_on_hardware_write_e
 
   // Simulate error in write() on TEST_ACTUATOR_HARDWARE_NAME and TEST_SYSTEM_HARDWARE_NAME
   // by setting first command interface to WRITE_FAIL_VALUE
-  test_controller_actuator->set_first_command_interface_value_to = WRITE_FAIL_VALUE;
-  test_controller_system->set_first_command_interface_value_to = WRITE_FAIL_VALUE;
+  test_controller_actuator->set_first_command_interface_value_to =
+    hardware_interface::testing_constants::WRITE_FAIL_VALUE;
+  test_controller_system->set_first_command_interface_value_to =
+    hardware_interface::testing_constants::WRITE_FAIL_VALUE;
   {
     auto previous_counter_lower = test_controller_actuator->internal_counter + 1;
     auto previous_counter_higher = test_controller_system->internal_counter + 1;

hardware_interface/include/hardware_interface/types/test_hardware_interface_constants.hpp

@@ -0,0 +1,29 @@
+// Copyright (c) 2023, FZI Forschungszentrum Informatik
+//
+// 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.
+//
+/// \author: Felix Exner <[email protected]>
+
+#ifndef HARDWARE_INTERFACE__TYPES__TEST_HARDWARE_INTERFACE_CONSTANTS_HPP_
+#define HARDWARE_INTERFACE__TYPES__TEST_HARDWARE_INTERFACE_CONSTANTS_HPP_
+namespace hardware_interface
+{
+namespace test_constants
+{
+/// Constants defining special values used inside tests to trigger things like deactivate or errors
+/// on read/write.
+constexpr double READ_FAIL_VALUE = 28282828.0;
+constexpr double WRITE_FAIL_VALUE = 23232323.0;
+}  // namespace test_constants
+}  // namespace hardware_interface
+#endif  // HARDWARE_INTERFACE__TYPES__TEST_HARDWARE_INTERFACE_CONSTANTS_HPP_

hardware_interface/test/test_components/test_actuator.cpp

@@ -16,6 +16,7 @@
 #include <vector>
 
 #include "hardware_interface/actuator_interface.hpp"
+#include "hardware_interface/types/test_hardware_interface_constants.hpp"
 
 using hardware_interface::ActuatorInterface;
 using hardware_interface::CommandInterface;
@@ -76,7 +77,7 @@ class TestActuator : public ActuatorInterface
   return_type read(const rclcpp::Time & /*time*/, const rclcpp::Duration & /*period*/) override
   {
     // simulate error on read
-    if (velocity_command_ == 28282828.0)
+    if (velocity_command_ == hardware_interface::test_constants::READ_FAIL_VALUE)
     {
       // reset value to get out from error on the next call - simplifies CM tests
       velocity_command_ = 0.0;
@@ -93,7 +94,7 @@ class TestActuator : public ActuatorInterface
   return_type write(const rclcpp::Time & /*time*/, const rclcpp::Duration & /*period*/) override
   {
     // simulate error on write
-    if (velocity_command_ == 23232323.0)
+    if (velocity_command_ == hardware_interface::test_constants::WRITE_FAIL_VALUE)
     {
       // reset value to get out from error on the next call - simplifies CM tests
       velocity_command_ = 0.0;

hardware_interface/test/test_components/test_system.cpp

@@ -18,6 +18,7 @@
 
 #include "hardware_interface/system_interface.hpp"
 #include "hardware_interface/types/hardware_interface_type_values.hpp"
+#include "hardware_interface/types/test_hardware_interface_constants.hpp"
 
 using hardware_interface::CommandInterface;
 using hardware_interface::return_type;
@@ -81,7 +82,7 @@ class TestSystem : public SystemInterface
   return_type read(const rclcpp::Time & /*time*/, const rclcpp::Duration & /*period*/) override
   {
     // simulate error on read
-    if (velocity_command_[0] == 28282828)
+    if (velocity_command_[0] == hardware_interface::test_constants::READ_FAIL_VALUE)
     {
       // reset value to get out from error on the next call - simplifies CM tests
       velocity_command_[0] = 0.0;
@@ -93,7 +94,7 @@ class TestSystem : public SystemInterface
   return_type write(const rclcpp::Time & /*time*/, const rclcpp::Duration & /*period*/) override
   {
     // simulate error on write
-    if (velocity_command_[0] == 23232323)
+    if (velocity_command_[0] == hardware_interface::test_constants::WRITE_FAIL_VALUE)
     {
       // reset value to get out from error on the next call - simplifies CM tests
       velocity_command_[0] = 0.0;

hardware_interface/test/test_resource_manager.cpp

@@ -25,6 +25,7 @@
 #include "hardware_interface/actuator_interface.hpp"
 #include "hardware_interface/resource_manager.hpp"
 #include "hardware_interface/types/lifecycle_state_names.hpp"
+#include "hardware_interface/types/test_hardware_interface_constants.hpp"
 #include "lifecycle_msgs/msg/state.hpp"
 #include "rclcpp_lifecycle/state.hpp"
 #include "ros2_control_test_assets/descriptions.hpp"
@@ -1546,8 +1547,6 @@ class ResourceManagerTestReadWriteError : public ResourceManagerTest
   const rclcpp::Duration duration = rclcpp::Duration::from_seconds(0.01);
 
   // values to set to hardware to simulate failure on read and write
-  static constexpr double READ_FAIL_VALUE = 28282828.0;
-  static constexpr double WRITE_FAIL_VALUE = 23232323.0;
 };
 
 TEST_F(ResourceManagerTestReadWriteError, handle_error_on_hardware_read)
@@ -1558,7 +1557,8 @@ TEST_F(ResourceManagerTestReadWriteError, handle_error_on_hardware_read)
   // check read methods failures
   check_read_or_write_failure(
     std::bind(&TestableResourceManager::read, rm, _1, _2),
-    std::bind(&TestableResourceManager::write, rm, _1, _2), READ_FAIL_VALUE);
+    std::bind(&TestableResourceManager::write, rm, _1, _2),
+    hardware_interface::test_constants::READ_FAIL_VALUE);
 }
 
 TEST_F(ResourceManagerTestReadWriteError, handle_error_on_hardware_write)
@@ -1569,7 +1569,8 @@ TEST_F(ResourceManagerTestReadWriteError, handle_error_on_hardware_write)
   // check write methods failures
   check_read_or_write_failure(
     std::bind(&TestableResourceManager::write, rm, _1, _2),
-    std::bind(&TestableResourceManager::read, rm, _1, _2), WRITE_FAIL_VALUE);
+    std::bind(&TestableResourceManager::read, rm, _1, _2),
+    hardware_interface::test_constants::WRITE_FAIL_VALUE);
 }
 
 TEST_F(ResourceManagerTest, test_caching_of_controllers_to_hardware)