upgrade to protobuf 4.21.5, add quiet mode, refactor code, add unit test

- update README.txt
- rename generated code directory
- refactor code:
    - extract methods
    - make code testable

unittest_extract_otp_secret_keys.py

@@ -0,0 +1,75 @@
+# Unit test for extract_otp_secret_keys.py
+
+# Run tests:
+# python -m unittest
+
+# Author: Scito (https://scito.ch)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+import unittest
+import csv
+import json
+import os
+
+import extract_otp_secret_keys
+
+class TestExtract(unittest.TestCase):
+
+    def test_extract_csv(self):
+        extract_otp_secret_keys.main(['-q', '-c', 'test_example_output.csv', 'example_export.txt'])
+
+        expected_csv = read_csv('example_output.csv')
+        actual_csv = read_csv('test_example_output.csv')
+
+        self.assertEqual(actual_csv, expected_csv)
+
+    def test_extract_json(self):
+        extract_otp_secret_keys.main(['-q', '-j', 'test_example_output.json', 'example_export.txt'])
+
+        expected_json = read_json('example_output.json')
+        actual_json = read_json('test_example_output.json')
+
+        self.assertEqual(actual_json, expected_json)
+
+    def setUp(self):
+        self.cleanup()
+
+    def tearDown(self):
+        self.cleanup()
+
+    def cleanup(self):
+        remove_file('test_example_output.csv')
+        remove_file('test_example_output.json')
+
+def remove_file(filename):
+    if os.path.exists(filename): os.remove(filename)
+
+def read_csv(filename):
+    """Returns a list of lines."""
+    with open(filename, "r") as infile:
+        lines = []
+        reader = csv.reader(infile)
+        for line in reader:
+            lines.append(line)
+        return lines
+
+def read_json(filename):
+    """Returns a list or a dictionary."""
+    with open(filename, "r") as infile:
+        return json.load(infile)
+
+
+if __name__ == '__main__':
+    unittest.main()