Merge pull request #408 from RocketPy-Team/tst/flight-class-protection

TST: new set of tests to the Flight class

Author: Gui-FernandesBR

tests/conftest.py

@@ -157,6 +157,43 @@ def calisto(calisto_motorless, cesaroni_m1670):  # old name: rocket
     return calisto
 
 
+@pytest.fixture
+def calisto_nose_to_tail(cesaroni_m1670):
+    """Create a simple object of the Rocket class to be used in the tests. This
+    is the same as the calisto fixture, but with the coordinate system
+    orientation set to "nose_to_tail" instead of "tail_to_nose". This allows to
+    check if the coordinate system orientation is being handled correctly in
+    the code.
+
+    Parameters
+    ----------
+    cesaroni_m1670 : rocketpy.SolidMotor
+        An object of the SolidMotor class. This is a pytest fixture too.
+
+    Returns
+    -------
+    rocketpy.Rocket
+        The Calisto rocket with the coordinate system orientation set to
+        "nose_to_tail". Rail buttons are already set, as well as the motor.
+    """
+    calisto = Rocket(
+        radius=0.0635,
+        mass=14.426,
+        inertia=(6.321, 6.321, 0.034),
+        power_off_drag="data/calisto/powerOffDragCurve.csv",
+        power_on_drag="data/calisto/powerOnDragCurve.csv",
+        center_of_mass_without_motor=0,
+        coordinate_system_orientation="nose_to_tail",
+    )
+    calisto.add_motor(cesaroni_m1670, position=1.373)
+    calisto.set_rail_buttons(
+        upper_button_position=-0.082,
+        lower_button_position=0.618,
+        angular_position=45,
+    )
+    return calisto
+
+
 @pytest.fixture
 def calisto_liquid_modded(calisto_motorless, liquid_motor):
     """Create a simple object of the Rocket class to be used in the tests. This
@@ -735,6 +772,35 @@ def flight_calisto(calisto, example_env):  # old name: flight
     )
 
 
+@pytest.fixture
+def flight_calisto_nose_to_tail(calisto_nose_to_tail, example_env):
+    """A rocketpy.Flight object of the Calisto rocket. This uses the calisto
+    with "nose_to_tail" coordinate system orientation, just as described in the
+    calisto_nose_to_tail fixture.
+
+    Parameters
+    ----------
+    calisto_nose_to_tail : rocketpy.Rocket
+        An object of the Rocket class. This is a pytest fixture too.
+    example_env : rocketpy.Environment
+        An object of the Environment class. This is a pytest fixture too.
+
+    Returns
+    -------
+    rocketpy.Flight
+        The Calisto rocket with the coordinate system orientation set to
+        "nose_to_tail".
+    """
+    return Flight(
+        environment=example_env,
+        rocket=calisto_nose_to_tail,
+        rail_length=5.2,
+        inclination=85,
+        heading=0,
+        terminate_on_apogee=False,
+    )
+
+
 @pytest.fixture
 def flight_calisto_robust(calisto_robust, example_env_robust):
     """A rocketpy.Flight object of the Calisto rocket. This uses the calisto
@@ -767,6 +833,42 @@ def flight_calisto_robust(calisto_robust, example_env_robust):
     )
 
 
+@pytest.fixture
+def flight_calisto_custom_wind(calisto_robust, example_env_robust):
+    """A rocketpy.Flight object of the Calisto rocket. This uses the calisto
+    with the aerodynamic surfaces and parachutes. The environment is a bit more
+    complex than the one in the flight_calisto_robust fixture. Now the wind is
+    set to 5m/s (x direction) and 2m/s (y direction), constant with altitude.
+
+    Parameters
+    ----------
+    calisto_robust : rocketpy.Rocket
+        An object of the Rocket class. This is a pytest fixture too.
+    example_env_robust : rocketpy.Environment
+        An object of the Environment class. This is a pytest fixture too.
+
+    Returns
+    -------
+    rocketpy.Flight
+
+    """
+    env = example_env_robust
+    env.set_atmospheric_model(
+        type="custom_atmosphere",
+        temperature=300,
+        wind_u=[(0, 5), (4000, 5)],
+        wind_v=[(0, 2), (4000, 2)],
+    )
+    return Flight(
+        environment=env,
+        rocket=calisto_robust,
+        rail_length=5.2,
+        inclination=85,
+        heading=0,
+        terminate_on_apogee=False,
+    )
+
+
 ## Dimensionless motors and rockets
 
 

tests/test_flight.py

@@ -79,6 +79,9 @@ def compute_static_margin_error_given_distance(position, static_margin, rocket):
     return rocket
 
 
+# Tests
+
+
 @patch("matplotlib.pyplot.show")
 def test_all_info(mock_show, flight_calisto_robust):
     """Test that the flight class is working as intended. This basically calls
@@ -656,3 +659,261 @@ def test_hybrid_motor_flight(mock_show, calisto_hybrid_modded):
     )
 
     assert test_flight.all_info() == None
+
+
+def test_surface_wind(flight_calisto_custom_wind):
+    """Tests the surface wind of the flight simulation. The expected values
+    are provided by the definition of the 'light_calisto_custom_wind' fixture.
+    If the fixture changes, this test must be updated.
+
+    Parameters
+    ----------
+    flight_calisto_custom_wind : rocketpy.Flight
+        Flight object to be tested. See the conftest.py file for more info
+        regarding this pytest fixture.
+    """
+    test = flight_calisto_custom_wind
+    atol = 1e-8
+    assert pytest.approx(2.0, abs=atol) == test.frontal_surface_wind
+    assert pytest.approx(-5.0, abs=atol) == test.lateral_surface_wind
+
+
+def test_effective_rail_length(flight_calisto_robust, flight_calisto_nose_to_tail):
+    """Tests the effective rail length of the flight simulation. The expected
+    values are calculated by hand, and should be valid as long as the rail
+    length and the position of the buttons and nozzle do not change in the
+    fixtures. If the fixtures change, this test must be updated. It is important
+    to keep
+
+    Parameters
+    ----------
+    flight_calisto_robust : rocketpy.Flight
+        Flight object to be tested. See the conftest.py file for more info
+        regarding this pytest fixture.
+    flight_calisto_nose_to_tail : rocketpy.Flight
+        Flight object to be tested. The difference here is that the rocket is
+        defined with the "nose_to_tail" orientation instead of the
+        "tail_to_nose" orientation. See the conftest.py file for more info
+        regarding this pytest fixture.
+    """
+    test1 = flight_calisto_robust
+    test2 = flight_calisto_nose_to_tail
+    atol = 1e-8
+
+    rail_length = 5.2
+    upper_button_position = 0.082
+    lower_button_position = -0.618
+    nozzle_position = -1.373
+
+    effective_1rl = rail_length - abs(upper_button_position - nozzle_position)
+    effective_2rl = rail_length - abs(lower_button_position - nozzle_position)
+
+    # test 1: Rocket with "tail_to_nose" orientation
+    assert pytest.approx(test1.effective_1rl, abs=atol) == effective_1rl
+    assert pytest.approx(test1.effective_2rl, abs=atol) == effective_2rl
+    # test 2: Rocket with "nose_to_tail" orientation
+    assert pytest.approx(test2.effective_1rl, abs=atol) == effective_1rl
+    assert pytest.approx(test2.effective_2rl, abs=atol) == effective_2rl
+
+
+def test_max_values(flight_calisto_robust):
+    """Test the max values of the flight. This tests if the max values are
+    close to the expected values. However, the expected values were NOT
+    calculated by hand, it was just copied from the test results. This is
+    because the expected values are not easy to calculate by hand, and the
+    results are not expected to change. If the results change, the test will
+    fail, and the expected values must be updated. If if want to update the
+    values, always double check if the results are really correct. Acceptable
+    reasons for changes in the results are: 1) changes in the code that
+    improve the accuracy of the simulation, 2) a bug was found and fixed. Keep
+    in mind that other tests may be more accurate than this one, for example,
+    the acceptance tests, which are based on the results of real flights.
+
+    Parameters
+    ----------
+    flight_calisto_robust : rocketpy.Flight
+        Flight object to be tested. See the conftest.py file for more info
+        regarding this pytest fixture.
+    """
+    test = flight_calisto_robust
+    atol = 5e-3
+    assert pytest.approx(105.2774, abs=atol) == test.max_acceleration_power_on
+    assert pytest.approx(105.2774, abs=atol) == test.max_acceleration
+    assert pytest.approx(0.85999, abs=atol) == test.max_mach_number
+    assert pytest.approx(285.90240, abs=atol) == test.max_speed
+
+
+def test_rail_buttons_forces(flight_calisto_custom_wind):
+    """Test the rail buttons forces. This tests if the rail buttons forces are
+    close to the expected values. However, the expected values were NOT
+    calculated by hand, it was just copied from the test results. The results
+    are not expected to change, unless the code is changed for bug fixes or
+    accuracy improvements.
+
+    Parameters
+    ----------
+    flight_calisto_custom_wind : rocketpy.Flight
+        Flight object to be tested. See the conftest.py file for more info
+        regarding this pytest fixture.
+    """
+    test = flight_calisto_custom_wind
+    atol = 5e-3
+    assert pytest.approx(3.80358, abs=atol) == test.max_rail_button1_normal_force
+    assert pytest.approx(1.63602, abs=atol) == test.max_rail_button1_shear_force
+    assert pytest.approx(1.19353, abs=atol) == test.max_rail_button2_normal_force
+    assert pytest.approx(0.51337, abs=atol) == test.max_rail_button2_shear_force
+
+
+@pytest.mark.parametrize(
+    "flight_time, expected_values",
+    [
+        ("t_initial", (0, 0, 0)),
+        ("out_of_rail_time", (0, 7.8068, 89.2325)),
+        ("apogee_time", (0.07534, -0.058127, -9.614386)),
+        ("t_final", (0, 0, 0.0017346294117130806)),
+    ],
+)
+def test_accelerations(flight_calisto_custom_wind, flight_time, expected_values):
+    """Tests if the acceleration in some particular points of the trajectory is
+    correct. The expected values were NOT calculated by hand, it was just
+    copied from the test results. The results are not expected to change,
+    unless the code is changed for bug fixes or accuracy improvements.
+
+    Parameters
+    ----------
+    flight_calisto_custom_wind : rocketpy.Flight
+        Flight object to be tested. See the conftest.py file for more info.
+    flight_time : str
+        The name of the attribute of the flight object that contains the time
+        of the point to be tested.
+    expected_values : tuple
+        The expected values of the acceleration vector at the point to be
+        tested.
+    """
+    expected_attr, expected_acc = flight_time, expected_values
+
+    test = flight_calisto_custom_wind
+    t = getattr(test, expected_attr)
+    atol = 5e-3
+
+    assert pytest.approx(expected_acc, abs=atol) == (
+        test.ax(t),
+        test.ay(t),
+        test.az(t),
+    ), f"Assertion error for acceleration vector at {expected_attr}."
+
+
+@pytest.mark.parametrize(
+    "flight_time, expected_values",
+    [
+        ("t_initial", (0, 0, 0)),
+        ("out_of_rail_time", (0, 2.248727, 25.703072)),
+        ("apogee_time", (-13.209436, 16.05115, -0.000257)),
+        ("t_final", (5, 2, -5.334289)),
+    ],
+)
+def test_velocities(flight_calisto_custom_wind, flight_time, expected_values):
+    """Tests if the velocity in some particular points of the trajectory is
+    correct. The expected values were NOT calculated by hand, it was just
+    copied from the test results. The results are not expected to change,
+    unless the code is changed for bug fixes or accuracy improvements.
+
+    Parameters
+    ----------
+    flight_calisto_custom_wind : rocketpy.Flight
+        Flight object to be tested. See the conftest.py file for more info.
+    flight_time : str
+        The name of the attribute of the flight object that contains the time
+        of the point to be tested.
+    expected_values : tuple
+        The expected values of the velocity vector at the point to be tested.
+    """
+    expected_attr, expected_vel = flight_time, expected_values
+
+    test = flight_calisto_custom_wind
+    t = getattr(test, expected_attr)
+    atol = 5e-3
+
+    assert pytest.approx(expected_vel, abs=atol) == (
+        test.vx(t),
+        test.vy(t),
+        test.vz(t),
+    ), f"Assertion error for velocity vector at {expected_attr}."
+
+
+@pytest.mark.parametrize(
+    "flight_time, expected_values",
+    [
+        ("t_initial", (1.6542528, 0.65918, -0.067107)),
+        ("out_of_rail_time", (5.05334, 2.01364, -1.7541)),
+        ("apogee_time", (2.35291, -1.8275, -0.87851)),
+        ("t_final", (0, 0, 141.42421)),
+    ],
+)
+def test_aerodynamic_forces(flight_calisto_custom_wind, flight_time, expected_values):
+    """Tests if the aerodynamic forces in some particular points of the
+    trajectory is correct. The expected values were NOT calculated by hand, it
+    was just copied from the test results. The results are not expected to
+    change, unless the code is changed for bug fixes or accuracy improvements.
+
+    Parameters
+    ----------
+    flight_calisto_custom_wind : rocketpy.Flight
+        Flight object to be tested. See the conftest.py file for more info.
+    flight_time : str
+        The name of the attribute of the flight object that contains the time
+        of the point to be tested.
+    expected_values : tuple
+        The expected values of the aerodynamic forces vector at the point to be
+        tested.
+    """
+    expected_attr, expected_R = flight_time, expected_values
+
+    test = flight_calisto_custom_wind
+    t = getattr(test, expected_attr)
+    atol = 5e-3
+
+    assert pytest.approx(expected_R, abs=atol) == (
+        test.R1(t),
+        test.R2(t),
+        test.R3(t),
+    ), f"Assertion error for aerodynamic forces vector at {expected_attr}."
+
+
+@pytest.mark.parametrize(
+    "flight_time, expected_values",
+    [
+        ("t_initial", (0.17179073815516033, -0.431117, 0)),
+        ("out_of_rail_time", (0.547026, -1.3727895, 0)),
+        ("apogee_time", (-0.5874848151271623, -0.7563596, 0)),
+        ("t_final", (0, 0, 0)),
+    ],
+)
+def test_aerodynamic_moments(flight_calisto_custom_wind, flight_time, expected_values):
+    """Tests if the aerodynamic moments in some particular points of the
+    trajectory is correct. The expected values were NOT calculated by hand, it
+    was just copied from the test results. The results are not expected to
+    change, unless the code is changed for bug fixes or accuracy improvements.
+
+    Parameters
+    ----------
+    flight_calisto_custom_wind : rocketpy.Flight
+        Flight object to be tested. See the conftest.py file for more info.
+    flight_time : str
+        The name of the attribute of the flight object that contains the time
+        of the point to be tested.
+    expected_values : tuple
+        The expected values of the aerodynamic moments vector at the point to
+        be tested.
+    """
+    expected_attr, expected_M = flight_time, expected_values
+
+    test = flight_calisto_custom_wind
+    t = getattr(test, expected_attr)
+    atol = 5e-3
+
+    assert pytest.approx(expected_M, abs=atol) == (
+        test.M1(t),
+        test.M2(t),
+        test.M3(t),
+    ), f"Assertion error for moment vector at {expected_attr}."