from matplotlib.sankey import Sankey

def test_sankey():

# lets just create a sankey instance and check the code runs

sankey = Sankey()

sankey.add()

def test_label():

s = Sankey(flows=[0.25], labels=['First'], orientations=[-1])

assert s.diagrams[0].texts[0].get_text() == 'First\n0.25'

def test_format_using_callable():

# test using callable by slightly incrementing above label example

def show_three_decimal_places(value):

return f'{value:.3f}'

s = Sankey(flows=[0.25], labels=['First'], orientations=[-1],

format=show_three_decimal_places)

assert s.diagrams[0].texts[0].get_text() == 'First\n0.250'