test plot_state_hinton

[1ucian0]

We dont have a test for plot_state_hinton in qiskit/visualization/state_visualization.py

[1ucian0]

on hold until #2968

[SimoneGasperini]

Hi @1ucian0! I would like to start contributing to Qiskit and this looks like a good first issue to begin with.

I read the contributions guidelines for testing visualization and I'm able to run the notebook test/ipynb/mpl_tester.ipynb in Binder. All the shown tests run successfuly, in particular I see the following result for tests about the Graph Matplotlib Drawer.

However, not all the tests in test_graph_matplotlib_drawer.py seem to be considered here and I don't understand why. For instance, the test for the function plot_state_hinton is included in the file (lines 117-127):

def test_plot_state_hinton(self):
    """test plot_state_hinton"""
    circuit = QuantumCircuit(1)
    circuit.x(0)

    # getting the state using backend
    backend = BasicAer.get_backend("statevector_simulator")
    result = execute(circuit, backend).result()
    state = result.get_statevector(circuit)

    self.graph_state_drawer(state=state, output="hinton", filename="hinton.png")

but it does not appear in the notebook result as you can see in the image above. The same happens for all the tests which rely on the state_drawer function imported from qiskit.visualization.state_visualization. In the other 14 cases (related to plot_histogram or plot_gate_map or plot_coupling_map), the test are collected correctly and the results are shown in the notebook. Can you please help me figuring things out?

[smturro2]

Hi @1ucian0 I'm looking to tackle adding these tests in the MPL drawer, from what I see plot_state_hinton is already being tested and I can see it in the binder.

Were there specific additional tests you wanted?

[1ucian0]

Thanks everyone for the heads up!

Indeed, this is already checked by snapshot testing. The next step is to add the snapshot tests as part of the CI/coverage, in the #6427 direction.