add unit test of initialization without error

test/test_cubic_spline_1d.py

@@ -12,12 +12,20 @@
 sys.path.append(str(Path(__file__).absolute().parent) + "/../src/components/course/cubic_spline_course")
 from cubic_spline import CubicSpline
 
+X_DATA_VALID = [0, 1, 2, 3, 4]
+X_DATA_INVALID = [0, -1, -2, 3, 5]
+Y_DATA = [1.7, -6, 5, 6.5, 0.0]
 
-def test_init_value_error():
-    x_points = [0, -1, -2, 3, 5]
-    y_points = [1.7, -6, 5, 6.5, 0.0]
 
+def test_init_value_error():
     with pytest.raises(ValueError) as e:
-        CubicSpline(x_points, y_points)
+        CubicSpline(X_DATA_INVALID, Y_DATA)
 
     assert str(e.value) == "X coordinate points must be stored in ascending order"
+
+
+def test_init_no_error():
+    cs = CubicSpline(X_DATA_VALID, Y_DATA)
+
+    assert cs.x_points == X_DATA_VALID
+    assert cs.y_points == Y_DATA