Move test_associativity

src/sage/categories/finite_semigroups_test.py

@@ -1,21 +1,14 @@
-class TestFiniteSemigroup():
+class TestFiniteSemigroup:
     """
     Tests for finite semigroups.
     """
 
     @staticmethod
     def category_instances():
         from sage.categories.examples.finite_semigroups import LeftRegularBand
+
         return [
-            LeftRegularBand(alphabet = ('a','b')), 
-            LeftRegularBand(alphabet = ('a','b','c')),
-            LeftRegularBand(alphabet = ('a','b','c', 'd'))
+            LeftRegularBand(alphabet=("a", "b")),
+            LeftRegularBand(alphabet=("a", "b", "c")),
+            LeftRegularBand(alphabet=("a", "b", "c", "d")),
         ]
-
-    def test_associativity(self, set_elements, max_runs):
-        """
-        Test associativity of multiplication of elements.
-        """
-        from sage.misc.misc import some_tuples
-        for x, y, z in some_tuples(set_elements, 3, max_runs):
-            assert (x * y) * z == x * (y * z)

src/sage/categories/semigroups_test.py

@@ -0,0 +1,13 @@
+class SemigroupTests:
+    """
+    Generic tests for semigroups.
+    """
+
+    def test_associativity(self, set_elements, max_runs):
+        """
+        Test associativity of multiplication of elements.
+        """
+        from sage.misc.misc import some_tuples
+
+        for x, y, z in some_tuples(set_elements, 3, max_runs):
+            assert (x * y) * z == x * (y * z)