MNT: refactor EmptyMotor properties to use funcify_method and add tests

Author: Gui-FernandesBR

rocketpy/motors/empty_motor.py

@@ -1,4 +1,4 @@
-from rocketpy.mathutils import Function
+from rocketpy.mathutils import Function, funcify_method
 from rocketpy.motors.motor import Motor
 
 
@@ -37,41 +37,41 @@ def __init__(self):
         self.I_13 = Function(0)
         self.I_23 = Function(0)
 
-    @property
+    @funcify_method("Time (s)", "Center of Propellant Mass (kg)", "linear", "zero")
     def center_of_propellant_mass(self):
-        return Function(0, "Time (s)", "Center of Propellant Mass (kg)")
+        return 0
 
-    @property
+    @funcify_method("Time (s)", "Exhaust Velocity (m/s)", "linear", "zero")
     def exhaust_velocity(self):
-        return Function(0, "Time (s)", "Exhaust Velocity (m/s)")
+        return 0
 
     @property
     def propellant_initial_mass(self):
         return 0
 
-    @property
+    @funcify_method("Time (s)", "Propellant I_11 (kg m²)", "linear", "zero")
     def propellant_I_11(self):
-        return Function(0, "Time (s)", "Propellant I_11 (kg m²)")
+        return 0
 
-    @property
+    @funcify_method("Time (s)", "Propellant I_12 (kg m²)", "linear", "zero")
     def propellant_I_12(self):
-        return Function(0, "Time (s)", "Propellant I_12 (kg m²)")
+        return 0
 
-    @property
+    @funcify_method("Time (s)", "Propellant I_13 (kg m²)", "linear", "zero")
     def propellant_I_13(self):
-        return Function(0, "Time (s)", "Propellant I_13 (kg m²)")
+        return 0
 
-    @property
+    @funcify_method("Time (s)", "Propellant I_22 (kg m²)", "linear", "zero")
     def propellant_I_22(self):
-        return Function(0, "Time (s)", "Propellant I_22 (kg m²)")
+        return 0
 
-    @property
+    @funcify_method("Time (s)", "Propellant I_23 (kg m²)", "linear", "zero")
     def propellant_I_23(self):
-        return Function(0, "Time (s)", "Propellant I_23 (kg m²)")
+        return 0
 
-    @property
+    @funcify_method("Time (s)", "Propellant I_33 (kg m²)", "linear", "zero")
     def propellant_I_33(self):
-        return Function(0, "Time (s)", "Propellant I_33 (kg m²)")
+        return 0
 
     @property
     def structural_mass_ratio(self):

tests/conftest.py

@@ -8,6 +8,7 @@
     "tests.fixtures.motor.liquid_fixtures",
     "tests.fixtures.motor.hybrid_fixtures",
     "tests.fixtures.motor.solid_motor_fixtures",
+    "tests.fixtures.motor.empty_motor_fixtures",
     "tests.fixtures.motor.tanks_fixtures",
     "tests.fixtures.motor.tank_geometry_fixtures",
     "tests.fixtures.motor.generic_motor_fixtures",

tests/fixtures/motor/empty_motor_fixtures.py

@@ -0,0 +1,14 @@
+import pytest
+
+from rocketpy.motors.empty_motor import EmptyMotor
+
+
+@pytest.fixture
+def empty_motor():
+    """An example of an empty motor with zero thrust and mass.
+
+    Returns
+    -------
+    rocketpy.EmptyMotor
+    """
+    return EmptyMotor()

tests/integration/test_empty_motor.py

@@ -0,0 +1,16 @@
+from unittest.mock import patch
+
+
+@patch("matplotlib.pyplot.show")
+def test_empty_motor_info(mock_show, empty_motor):  # pylint: disable=unused-argument
+    """Tests the LiquidMotor.all_info() method.
+
+    Parameters
+    ----------
+    mock_show : mock
+        Mock of the matplotlib.pyplot.show function.
+    empty_motor : rocketpy.EmptyMotor
+        The EmptyMotor object to be used in the tests.
+    """
+    assert empty_motor.info() is None
+    assert empty_motor.all_info() is None