def test_add(self):
"""Addition operator."""
# adding points is undefined
with self.assertRaises(
TypeError, msg="Point2D addition did not raise a TypeError."):
Point2D() + Point2D()
def test_distance_to(self):
"""Testing method distance_to()."""
a = Point2D(-1, 5)
b = Point2D(9, 4)
v = a.distance_to(b)
r = sqrt((9 + 1)**2 + (4 - 5)**2)
self.assertEqual(v, r, "Point2D to Point2D distance is incorrect.")
def test_subtract(self):
"""Subtraction operator."""
# subtracting points is undefined
with self.assertRaises(
TypeError,
msg="Point2D subtraction did not raise a TypeError."):
Point2D() - Point2D()
def test_initialise_default(self):
"""Default initialisation, point at local origin."""
v = Point2D()
self.assertEqual(v.x, 0.0,
"Default initialisation is not (0,0,0) [X].")
self.assertEqual(v.y, 0.0,
"Default initialisation is not (0,0,0) [Y].")
def test_iter(self):
"""Obtain values by iteration."""
p = Point2D(2.5, 6.7)
l = list(p)
self.assertEqual(
len(l), 2,
"Iteration failed to return the correct number of items.")
self.assertEqual(l[0], 2.5, "Iteration failed [X].")
self.assertEqual(l[1], 6.7, "Iteration failed [Y].")
def test_y(self):
"""Get/set y co-ordinate."""
v = Point2D(2.5, 6.7)
# get y attribute
self.assertEqual(v.y, 6.7, "Getting y attribute failed.")
# set y attribute
v.y = -7.1
self.assertEqual(v.y, -7.1, "Setting y attribute failed.")
def test_x(self):
"""Get/set x co-ordinate."""
v = Point2D(2.5, 6.7)
# get x attribute
self.assertEqual(v.x, 2.5, "Getting x attribute failed.")
# set x attribute
v.x = 10.0
self.assertEqual(v.x, 10.0, "Setting x attribute failed.")
def test_copy(self):
"""Testing method copy()."""
v = Point2D(1.0, 2.0)
r = v.copy()
# check a new instance has been created by modifying the original
v.x = 5.0
v.y = 6.0
self.assertEqual(r.x, 1.0, "Copy failed [X].")
self.assertEqual(r.y, 2.0, "Copy failed [Y].")
def test_not_equal(self):
"""Inequality operator."""
self.assertFalse(
Point2D(1, 2) != Point2D(1, 2),
"Inequality operator returned true for equal points.")
self.assertTrue(
Point2D(5, 2) != Point2D(1, 2),
"Inequality operator returned false for a point with non-equal x components."
)
self.assertTrue(
Point2D(1, 5) != Point2D(1, 2),
"Inequality operator returned false for a point with non-equal y components."
)
def test_indexing(self):
"""Getting/setting components by indexing."""
v = Point2D(2.5, 6.7)
v[0] = 1.0
v[1] = 2.0
# check getting/setting via valid indexes
self.assertEqual(v[0], 1.0, "Indexing failed [X].")
self.assertEqual(v[1], 2.0, "Indexing failed [Y].")
# check invalid indexes
with self.assertRaises(
IndexError,
msg="Invalid positive index did not raise IndexError."):
r = v[3]
with self.assertRaises(
IndexError,
msg="Invalid negative index did not raise IndexError."):
r = v[-1]
def test_initialise_invalid(self):
"""Initialisation with invalid types should raise a TypeError."""
with self.assertRaises(TypeError, msg="Initialised with a string."):
Point2D("spoon")
def test_initialise_indexable(self):
"""Initialisation with an indexable object."""
v = Point2D(1.0, 2.0)
self.assertEqual(v.x, 1.0, "Initialisation with indexable failed [X].")
self.assertEqual(v.y, 2.0, "Initialisation with indexable failed [Y].")