def test_pump_4_3_liters(self):
pump.Pump(self.mock_pi_io, self.mock_clock,
pump_pin=6).pump_water(4300.0)
# Pump should call wait() exactly once.
self.assertEqual(1, len(self.mock_clock.wait.call_args_list))
wait_time_actual = self.mock_clock.wait.call_args[0][0]
# At 4.3 L/min, pump should run for exactly 60 seconds.
wait_time_expected = 60.0
# There is loss of precision with floating point arithmetic, so we
# verify that the values are equal to several significant digits.
self.assertAlmostEqual(wait_time_expected, wait_time_actual)
# Verify the signal gets sent to turn the pump pin on, then off.
self.mock_pi_io.turn_pin_on.assert_called_once_with(6)
self.mock_pi_io.turn_pin_off.assert_called_once_with(6)
def test_pump_negative_amount_raises_ValueError(self):
"""Attempting to pump a negative amount of water raises an exception."""
with self.assertRaises(ValueError):
pump.Pump(self.mock_pi_io, self.mock_clock, 6).pump_water(-5.0)
def test_pump_zero_does_not_turn_on_pump(self):
"""Pumping zero milliliters is allowed, but should not turn on pump."""
pump.Pump(self.mock_pi_io, self.mock_clock, 6).pump_water(0.0)
self.assertFalse(self.mock_pi_io.turn_pin_on.called)
self.assertFalse(self.mock_clock.wait.called)
self.assertFalse(self.mock_pi_io.turn_pin_off.called)