Add auth functions and tests.

Signed-off-by: Zack Koppert <[email protected]>

auth.py

@@ -0,0 +1,20 @@
+"""This is the module that contains functions related to authenticating to GitHub with a personal access token."""
+
+import os
+import github3
+
+
+def auth_to_github():
+    """Connect to github.com or GitHub Enterprise, depending on env variables."""
+    ghe = os.getenv("GH_ENTERPRISE_URL", default="").strip()
+    token = os.getenv("GH_TOKEN")
+    if ghe and token:
+        github_connection = github3.github.GitHubEnterprise(ghe, token=token)
+    elif token:
+        github_connection = github3.login(token=os.getenv("GH_TOKEN"))
+    else:
+        raise ValueError("GH_TOKEN environment variable not set")
+
+    if not github_connection:
+        raise ValueError("Unable to authenticate to GitHub")
+    return github_connection  # type: ignore

test_auth.py

@@ -0,0 +1,51 @@
+"""Test cases for the auth module."""
+import unittest
+from unittest.mock import patch
+import auth
+
+
+class TestAuth(unittest.TestCase):
+    """
+    Test case for the auth module.
+    """
+
+    @patch("os.getenv")
+    @patch("github3.github.GitHubEnterprise")
+    def test_auth_to_github_enterprise(self, mock_github_enterprise, mock_getenv):
+        """
+        Test the auth_to_github function when the GH_ENTERPRISE_URL and GH_TOKEN environment variables are set.
+        """
+        mock_getenv.side_effect = ["https://github.enterprise.com", "token"]
+        mock_github_enterprise.return_value = "Authenticated to GitHub Enterprise"
+
+        result = auth.auth_to_github()
+
+        self.assertEqual(result, "Authenticated to GitHub Enterprise")
+
+    @patch("github3.login")
+    @patch("os.getenv")
+    def test_auth_to_github_com(self, mock_login, mock_getenv):
+        """
+        Test the auth_to_github function when only the GH_TOKEN environment variable is set.
+        """
+        mock_getenv.side_effect = ["", "token"]
+        mock_login.return_value = "Authenticated to github.com"
+
+        result = auth.auth_to_github()
+
+        self.assertEqual(result.url, "Authenticated to github.com")
+
+    @patch("os.getenv")
+    def test_auth_to_github_no_token(self, mock_getenv):
+        """
+        Test the auth_to_github function when the GH_TOKEN environment variable is not set.
+        Expect a ValueError to be raised.
+        """
+        mock_getenv.side_effect = ["", ""]
+
+        with self.assertRaises(ValueError):
+            auth.auth_to_github()
+
+
+if __name__ == "__main__":
+    unittest.main()