Set command buffers in test_controller when ALL interfaces are requested

When only the controller_interface::InterfaceConfiguration.type == ALL is given,
but the names vector is empty, the command buffer vector is created with size 0
However, when writing the commands in update(), values for all command_interfaces
are being happily read from a vector with size 0, which is not very optimal.

With this commit, we resize the command buffer on on_activate when ALL interfaces
are requested, since at that point we know all available interfaces, as they
are set by the controller_manager's switch() method.

controller_manager/test/test_controller/test_controller.cpp

@@ -94,6 +94,20 @@ CallbackReturn TestController::on_configure(const rclcpp_lifecycle::State & /*pr
   return CallbackReturn::SUCCESS;
 }
 
+CallbackReturn TestController::on_activate(const rclcpp_lifecycle::State & /*previous_state*/)
+{
+  if (cmd_iface_cfg_.type == controller_interface::interface_configuration_type::ALL)
+  {
+    external_commands_for_testing_.resize(command_interfaces_.size(), 0.0);
+    cmd_iface_cfg_.names.resize(command_interfaces_.size());
+    for (size_t i = 0; i < command_interfaces_.size(); ++i)
+    {
+      cmd_iface_cfg_.names[i] = command_interfaces_[i].get_name();
+    }
+  }
+  return CallbackReturn::SUCCESS;
+}
+
 CallbackReturn TestController::on_cleanup(const rclcpp_lifecycle::State & /*previous_state*/)
 {
   if (simulate_cleanup_failure)

controller_manager/test/test_controller/test_controller.hpp

@@ -55,6 +55,9 @@ class TestController : public controller_interface::ControllerInterface
   CONTROLLER_MANAGER_PUBLIC
   CallbackReturn on_configure(const rclcpp_lifecycle::State & previous_state) override;
 
+  CONTROLLER_MANAGER_PUBLIC
+  CallbackReturn on_activate(const rclcpp_lifecycle::State & previous_state) override;
+
   CONTROLLER_MANAGER_PUBLIC
   CallbackReturn on_cleanup(const rclcpp_lifecycle::State & previous_state) override;