Implemented SheerkaOntology

tests/non_reg/test_sheerka_display.py

@@ -2,11 +2,6 @@ from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka
 
 
 class TestSheerkaNonRegDisplay(TestUsingMemoryBasedSheerka):
-    @classmethod
-    def teardown_class(cls):
-        # At the end of the tests, sheerka singleton instance will be corrupted
-        # Ask for a new one
-        TestSheerkaNonRegDisplay.singleton_instance = None
 
     def test_i_can_display_results_when_return_values_processing_is_on(self, capsys):
         init = [
@@ -27,7 +22,7 @@ class TestSheerkaNonRegDisplay(TestUsingMemoryBasedSheerka):
         ]
         sheerka = self.init_scenario(init)
         capsys.readouterr()
-        
+
         sheerka.enable_process_return_values = True
         sheerka.evaluate_user_input("desc(foo)")
 
@@ -72,4 +67,24 @@ props     : {}
         captured = capsys.readouterr()
         assert captured.out == """ReturnValue(who=evaluators.Concept, status=True, value=(1001)foo)
 ReturnValue(who=evaluators.Concept, status=True, value=(1002)foo)
+"""
+
+    def test_i_can_list_ontologies(self, capsys):
+        init = [
+            "push_ontology('test 1')",
+            "push_ontology('test 2')",
+            "pop_ontology()",
+            "push_ontology('test 3')",
+        ]
+        sheerka = self.init_scenario(init)
+        capsys.readouterr()
+
+        sheerka.enable_process_return_values = True
+        sheerka.evaluate_user_input("ontologies()")
+
+        captured = capsys.readouterr()
+        assert captured.out == """test 3
+test 1
+#unit_test#
+__default__
 """