skpkg: migrate tests folder

tests/test_functions.py

@@ -0,0 +1,40 @@
+import numpy as np
+import pytest
+
+from diffpy.fourigui import functions  # noqa
+
+
+def test_dot_product_2D_list():
+    a = [1, 2]
+    b = [3, 4]
+    expected = 11.0
+    actual = functions.dot_product(a, b)
+    assert actual == expected
+
+
+def test_dot_product_3D_list():
+    a = [1, 2, 3]
+    b = [4, 5, 6]
+    expected = 32.0
+    actual = functions.dot_product(a, b)
+    assert actual == expected
+
+
+@pytest.mark.parametrize(
+    "a, b, expected",
+    [
+        # Test whether the dot product function works with 2D and 3D vectors
+        # C1: lists, expect correct float output
+        ([1, 2], [3, 4], 11.0),
+        ([1, 2, 3], [4, 5, 6], 32.0),
+        # C2: tuples, expect correct float output
+        ((1, 2), (3, 4), 11.0),
+        ((1, 2, 3), (4, 5, 6), 32.0),
+        # C3: numpy arrays, expect correct float output
+        (np.array([1, 2]), np.array([3, 4]), 11.0),
+        (np.array([1, 2, 3]), np.array([4, 5, 6]), 32.0),
+    ],
+)
+def test_dot_product(a, b, expected):
+    actual = functions.dot_product(a, b)
+    assert actual == expected

tests/test_version.py

@@ -1,6 +1,6 @@
 """Unit tests for __version__.py."""
 
-import diffpy.fourigui
+import diffpy.fourigui  # noqa
 
 
 def test_package_version():