Write tests for forcetorque plugin

[traversaro]

Example for gazebo-classic: https://github.com/robotology/gazebo-yarp-plugins/tree/master/tests .

In general, we need to understand if we want to launch gz-sim as a library, or as an executable .

[traversaro]

We can also check if somebody replies here: https://discord.com/channels/1077825543698927656/1080763334384697430/1138404740905046076 with useful pointers.

[traversaro]

To launch gz-sim as a library, a possible example is https://github.com/gazebosim/gz-sim/tree/gz-sim7/examples/standalone/custom_server .

See also the test for the FT system in gazebo itself: https://github.com/gazebosim/gz-sim/blob/gz-sim7/test/integration/force_torque_system.cc#L48 .

[traversaro]

I found some related material: https://gazebosim.org/api/sim/7/test_fixture.html and https://github.com/gazebosim/gz-sim/tree/gz-sim7/examples/standalone/gtest_setup . In particular the example shows also how to integrate with googletest, so probably it is a good starting point!

[lucapa17]

@traversaro
For the moment we have done this 5589283.
We used gz::sim::TestFixture. The test simply compares the values coming from the yarp port and the expected values (e.g. forceZ must be equal to -9.8*10).
We don't know if it is a correct idea or if we should consider something else.

[traversaro]

Nice start! The test is passing fine on your machines? Can you open a PR so that we can see if the test is passing fine also in the CI?

Probably a possible improvement is not directly read the port, but read it through the multipleanalogsensorsclient device. For an example of how to read the data via the multipleanalogsensorsclient , check the code in robotology/yarp#2881 (comment) (just the first section, the second section will only be usable once that PR is merged and released).