def test__similar_items__bad():
"""ensure the similar_items() method raises an exception for an item not in training data"""
with pytest.raises(AssertionError):
model = RankFM(factors=2)
model.fit(intx_train_pd_int)
similar = model.similar_items(99, n_items=3)
def test__similar_items__good():
"""test the similar_items() method for a valid [item_id]"""
model = RankFM(factors=2)
model.fit(intx_train_pd_int)
similar = model.similar_items(1, n_items=3)
shape = similar.shape == (3, )
items = np.isin(similar, intx_train_pd_int['item_id'].unique()).all()
assert shape and items