def test_print_solution_returns_value():
"""Ensure that `_print_solution` returns `True` if there was a solution."""
solver_with_solutions = mock.Mock()
solver_with_solutions.solve.return_value = [["foo"]]
assert _print_solution(solver_with_solutions)
solver_without_solutions = mock.Mock()
solver_without_solutions.solve.return_value = []
assert not _print_solution(solver_without_solutions)
def test_print_solution(capsys):
"""Ensure that we print the solution, without printing duplicates."""
solver = mock.Mock()
solver.solve.return_value = [["foo", "bar"], ["bar", "foo"]]
_print_solution(solver)
out, _ = capsys.readouterr()
# Should print the first item, but then skip the second item as it's been
# seen.
assert out == "foo bar\n"
