diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/utils/__init__.py b/tests/utils/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/utils/gsheet/__init__.py b/tests/utils/gsheet/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/utils/gsheet/test_gsheet_helper.py b/tests/utils/gsheet/test_gsheet_helper.py
new file mode 100644
index 0000000..251c8f4
--- /dev/null
+++ b/tests/utils/gsheet/test_gsheet_helper.py
@@ -0,0 +1,25 @@
+from unittest import TestCase
+from test.support import EnvironmentVarGuard
+
+from utils.gsheet.helper import GoogleSheetHelper
+class TestGsheetHelper(TestCase):
+    def setUp(self):
+        self.env = EnvironmentVarGuard()
+        self.env.clear()
+        
+    def test_google_credentials_required(self):
+        """
+            Test to ensure that GOOGLE_CREDENTIALS are always set in the environment variables 
+            while creating a GoogleSheetHelper.
+        """
+        with self.assertRaises(ValueError):
+            GoogleSheetHelper()
+    
+    def test_google_credentials_provided_has_required_values(self):
+        """
+            Test to ensure the GOOGLE_CREDENTIALS provided has required values e.g
+            sheet_name
+        """
+        self.env.set('GOOGLE_CREDENTIALS', "{}")
+        with self.assertRaises(ValueError):
+            GoogleSheetHelper()
diff --git a/tests/utils/twitter/__init__.py b/tests/utils/twitter/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/utils/twitter/test_stream_listener.py b/tests/utils/twitter/test_stream_listener.py
new file mode 100644
index 0000000..a347788
--- /dev/null
+++ b/tests/utils/twitter/test_stream_listener.py
@@ -0,0 +1,20 @@
+from unittest import TestCase
+from test.support import EnvironmentVarGuard
+
+from utils.twitter.stream_listener import Listener
+
+
+class TestTweeterStream(TestCase):
+    def setUp(self):
+        self.env = EnvironmentVarGuard()
+        self.env.clear()
+    
+    def test_keys_required_for_twitter_authorization_are_provided(self):
+        """
+            Test to ensure that keys required for twitter authoization i.e
+            CLIENT_KEY, CLIENT_SECRET, ACCESS_TOKEN and ACCESS_SECRET
+            are always set in the environment variables 
+            while creating a StreamListener.
+        """
+        with self.assertRaises(ValueError):
+            Listener()
diff --git a/utils/gsheet/helper.py b/utils/gsheet/helper.py
index 17073dc..2ccc4d3 100644
--- a/utils/gsheet/helper.py
+++ b/utils/gsheet/helper.py
@@ -18,12 +18,18 @@ def __init__(self) -> None:
             'https://spreadsheets.google.com/feeds',
             'https://www.googleapis.com/auth/drive'
         ]
+        credentials = os.getenv('GOOGLE_CREDENTIALS')
+        if not credentials:
+            raise ValueError("GOOGLE_CREDENTIALS must be set as an environment variable.")
         google_credentials = json.loads(
-            eval(os.getenv('GOOGLE_CREDENTIALS')), strict=False)
+            credentials, strict=False)
+        sheet_name = google_credentials.get('sheet_name')
+        if not sheet_name:
+            raise ValueError("Sheet name has not been set in the GOOGLE_CREDENTIALS environment variable.")
         self.__credentials = ServiceAccountCredentials.from_json_keyfile_dict(
             google_credentials, scopes=self.__scope)
         self.__client = gspread.authorize(self.__credentials)
-        self.__sheet_name = google_credentials['sheet_name']
+        self.__sheet_name = sheet_name
         self.__sheet = self.__client.open(self.__sheet_name).sheet1
 
     def open_sheet(self) -> Optional[dict]:
diff --git a/utils/twitter/stream_listener.py b/utils/twitter/stream_listener.py
index 6abc860..5650375 100644
--- a/utils/twitter/stream_listener.py
+++ b/utils/twitter/stream_listener.py
@@ -11,8 +11,21 @@ class Listener(StreamListener):
 
     def __init__(self):
         super(Listener, self).__init__()
-        self.__auth = OAuthHandler(os.getenv('CLIENT_KEY'), os.getenv('CLIENT_SECRET'))  # type: OAuthHandler
-        self.__auth.set_access_token(os.getenv('ACCESS_TOKEN'), os.getenv('ACCESS_SECRET'))
+        client_key = os.getenv('CLIENT_KEY')
+        client_secret = os.getenv('CLIENT_SECRET')
+        access_token = os.getenv('ACCESS_TOKEN')
+        access_secret = os.getenv('ACCESS_SECRET')
+        
+        if not client_key:
+            raise ValueError("CLIENT_KEY not set as an environment variable.")
+        if not client_secret:
+            raise ValueError("CLIENT_SECRET not set as an environment variable.")
+        if not access_token:
+            raise ValueError("ACCESS_TOKEN not set as an environment variable.")
+        if not access_secret:
+            raise ValueError("ACCESS_SECRET not set as an environment variable.")
+        self.__auth = OAuthHandler(client_key, client_secret)  # type: OAuthHandler
+        self.__auth.set_access_token(access_token, access_secret)
         self.__stream = []  # type: list
 
     @property