diff --git a/cat_win/tests/src/domain/test_arguments.py b/cat_win/tests/src/domain/test_arguments.py
index 6d9972a..76e3050 100644
--- a/cat_win/tests/src/domain/test_arguments.py
+++ b/cat_win/tests/src/domain/test_arguments.py
@@ -38,6 +38,32 @@ def test_delete_args(self):
         self.assertListEqual(u_args.args, [])
         self.assertEqual(len(u_args.args_id), 0)
 
+    def test_find_first(self):
+        u_args = Arguments()
+        u_args.set_args([(ARGS_NUMBER, 'a'), (ARGS_LLENGTH, 'b')])
+        self.assertTupleEqual(u_args.find_first(ARGS_NUMBER, ARGS_LLENGTH, False), (ARGS_NUMBER, 'a'))
+        u_args = Arguments()
+        u_args.set_args([(ARGS_NUMBER, 'a'), (ARGS_LLENGTH, 'b')])
+        self.assertTupleEqual(u_args.find_first(ARGS_LLENGTH, ARGS_NUMBER, False), (ARGS_NUMBER, 'a'))
+        u_args = Arguments()
+        u_args.set_args([(ARGS_NUMBER, 'a'), (ARGS_ENDS, 'c')])
+        self.assertTupleEqual(u_args.find_first(ARGS_NUMBER, ARGS_LLENGTH, False), (ARGS_NUMBER, 'a'))
+        u_args = Arguments()
+        u_args.set_args([(ARGS_ENDS, 'c'), (ARGS_LLENGTH, 'b')])
+        self.assertTupleEqual(u_args.find_first(ARGS_LLENGTH, ARGS_NUMBER, False), (ARGS_LLENGTH, 'b'))
+        u_args = Arguments()
+        u_args.set_args([(ARGS_ENDS, 'c')])
+        self.assertEqual(u_args.find_first(ARGS_LLENGTH, ARGS_NUMBER, False), None)
+        u_args = Arguments()
+        u_args.set_args([(ARGS_NUMBER, 'a'), (ARGS_LLENGTH, 'b')])
+        self.assertTupleEqual(u_args.find_first(ARGS_NUMBER, ARGS_LLENGTH, True), (ARGS_NUMBER, 'a'))
+        u_args = Arguments()
+        u_args.set_args([(ARGS_NUMBER, 'a'), (ARGS_LLENGTH, 'b')])
+        self.assertEqual(u_args.find_first(ARGS_LLENGTH, ARGS_NUMBER, True), None)
+        u_args = Arguments()
+        u_args.set_args([(ARGS_ENDS, 'c')])
+        self.assertEqual(u_args.find_first(ARGS_LLENGTH, ARGS_NUMBER, True), None)
+
     def test_reduce_list(self):
         test_list = [(ARGS_NUMBER, 'a'), (ARGS_LLENGTH, 'b')]
         reduced_list = reduce_list(test_list)
diff --git a/cat_win/tests/src/domain/test_file.py b/cat_win/tests/src/domain/test_file.py
index 5af9384..e539274 100644
--- a/cat_win/tests/src/domain/test_file.py
+++ b/cat_win/tests/src/domain/test_file.py
@@ -32,3 +32,8 @@ def test_file_plaintext(self):
 
         file.set_plaintext(False)
         self.assertEqual(file.plaintext, False)
+
+    def test_file_hashable(self):
+        file = File('testPath', 'testName')
+        file2 = File('testPath', 'testName')
+        self.assertSetEqual({file, file2}, {file2})
diff --git a/cat_win/tests/src/service/test_editor.py b/cat_win/tests/src/service/test_editor.py
index 3264036..56c3638 100644
--- a/cat_win/tests/src/service/test_editor.py
+++ b/cat_win/tests/src/service/test_editor.py
@@ -959,7 +959,7 @@ def test_editor_interrupt(self):
         with self.assertRaises(KeyboardInterrupt):
             with patch('sys.stderr', new=StdOutMock()) as fake_out:
                 editor._action_interrupt()
-            self.assertEqual('Interrupting...\n', fake_out.getvalue())
+        self.assertEqual('Interrupting...\n', fake_out.getvalue())
 
     def test__action_resize(self):
         editor = Editor('', '')