added tests for zipviewer

cat_win/tests/test_zipviewer.py

@@ -0,0 +1,33 @@
+from unittest.mock import patch
+from unittest import TestCase
+import os
+
+from cat_win.tests.mocks.std import StdOutMock
+from cat_win.util.zipviewer import display_zip
+# import sys
+# sys.path.append('../cat_win')
+test_file_dir = os.path.join(os.path.dirname(__file__), 'texts')
+test_file_path  = os.path.join(test_file_dir, 'test.txt')
+test_zip_file_dir = os.path.join(os.path.dirname(__file__), 'resources')
+test_zip_file_path  = os.path.join(test_zip_file_dir, 'test.zip')
+
+
+class TestZipviewer(TestCase):
+    maxDiff = None
+
+    def test_display_zip_bad_file(self):
+        self.assertEqual(display_zip('', lambda x: x), False)
+        self.assertEqual(display_zip(test_file_path, lambda x: x), False)
+
+    def test_display_zip(self):
+        self.assertEqual(display_zip(test_zip_file_path, lambda x: x), True)
+
+    def test_display_zip_output(self):
+        expected_output = f"The file '{test_zip_file_path}' has been detected to be a zip-file. "
+        expected_output += 'The archive contains the following files:\n'
+        expected_output += 'FileName       FileSize CompressedFileSize\n'
+        expected_output += 'test.txt            189                145\n'
+        expected_output += 'test_empty.txt        0                  0\n'
+        with patch('cat_win.cat.sys.stdout', new=StdOutMock()) as fake_out:
+            display_zip(test_zip_file_path, lambda x: x)
+            self.assertEqual(fake_out.getvalue(), expected_output)