Merge pull request #6 from Animesh-Ghosh/add-tests-with-mock

Add Tests for `get_titles` function

README.md

@@ -13,6 +13,13 @@
 
      ![r/developersIndia About widget](https://user-images.githubusercontent.com/34342551/185678556-e4c911c9-fb12-49da-9ca6-8f8ce2ad9b5a.png)
 
+## Tests
+
+To run the tests, simply run the following command in the Python virtual environment:
+
+```bash
+$ python -m unittest
+```
 
 ## Resources
 

main.py

@@ -1,3 +1,7 @@
+'''
+    This script is used for changing the text below total members & live
+    members count in the developersIndia subreddit
+'''
 import praw
 import os
 import random
@@ -10,7 +14,7 @@ reddit_pass = os.environ["REDDIT_PASSWORD"]
 
 def get_titles():
     with open('dataset.json', 'r') as f:
-         data = json.load(f)
+        data = json.load(f)
 
     titles = data['titles']
     currentlyViewingText, subscribersText = random.sample(titles, 2)
@@ -38,5 +42,5 @@ def update_titles():
     widgets.refresh()
     widgets.id_card.mod.update(subscribersText=titles[1])
 
-
-update_titles()
+if __name__ == '__main__':
+    update_titles()

test_get_titles.py

@@ -0,0 +1,28 @@
+import unittest
+from unittest.mock import patch
+
+# patch out the environ dictionary
+# used to instantiate global variables in the titles_updater script
+# maybe move the call to os.environ in the script to the update_titles method?
+environ_patcher = patch.dict('os.environ', {
+    'REDDIT_CLIENT_ID': '',
+    'REDDIT_CLIENT_SECRET': '',
+    'REDDIT_PASSWORD': ''
+})
+environ_patcher.start()
+
+from main import get_titles
+
+class TestGetTitles(unittest.TestCase):
+    @patch('main.json.load', return_value={'titles': ['foo', 'bar', 'baz']})
+    def test_get_titles_returns_a_list(self, _):
+        titles = get_titles()
+        self.assertIsInstance(titles, list)
+
+    @patch('main.json.load', return_value={'titles': ['foo', 'bar', 'baz']})
+    def test_get_titles_contains_titles_from_dataset_file(self, mock_json_load):
+        titles = get_titles()
+
+        self.assertTrue(all(map(lambda title: title in mock_json_load.return_value['titles'], titles)))
+
+environ_patcher.stop()