def test_overlay_file_bad_type():
plot = SigPlot()
assert plot.inputs == []
path = 3
with pytest.raises(TypeError):
plot.overlay_file(path)
def test_overlay_file_non_empty():
plot = SigPlot()
assert plot.inputs == []
path = "foo.tmp"
plot.overlay_file(path)
assert plot.inputs == [path]