added circle CI config with basic unit tests

tests/unit/test_auth.py

@@ -0,0 +1,73 @@
+# tests/unit/test_auth.py
+
+import pytest
+import spotipy
+import tidalapi
+import yaml
+import sys
+from unittest import mock
+from spotify_to_tidal.auth import open_spotify_session, open_tidal_session
+
+
+def test_open_spotify_session(mocker):
+    # Mock the SpotifyOAuth class
+    mock_spotify_oauth = mocker.patch(
+        "spotify_to_tidal.auth.spotipy.SpotifyOAuth", autospec=True
+    )
+    mock_spotify_instance = mocker.patch(
+        "spotify_to_tidal.auth.spotipy.Spotify", autospec=True
+    )
+
+    # Define a mock configuration
+    mock_config = {
+        "username": "test_user",
+        "client_id": "test_client_id",
+        "client_secret": "test_client_secret",
+        "redirect_uri": "http://localhost/",
+    }
+
+    # Create a mock SpotifyOAuth instance
+    mock_oauth_instance = mock_spotify_oauth.return_value
+    mock_oauth_instance.get_access_token.return_value = "mock_access_token"
+
+    # Call the function under test
+    spotify_instance = open_spotify_session(mock_config)
+
+    # Assert that the SpotifyOAuth was called with correct parameters
+    mock_spotify_oauth.assert_called_once_with(
+        username="test_user",
+        scope="playlist-read-private",
+        client_id="test_client_id",
+        client_secret="test_client_secret",
+        redirect_uri="http://localhost/",
+        requests_timeout=2,
+    )
+
+    # Assert that the Spotify instance was created
+    mock_spotify_instance.assert_called_once_with(oauth_manager=mock_oauth_instance)
+    assert spotify_instance == mock_spotify_instance.return_value
+
+
+def test_open_spotify_session_oauth_error(mocker):
+    # Mock the SpotifyOAuth class and simulate an OAuth error
+    mock_spotify_oauth = mocker.patch(
+        "spotify_to_tidal.auth.spotipy.SpotifyOAuth", autospec=True
+    )
+    mock_spotify_oauth.return_value.get_access_token.side_effect = (
+        spotipy.SpotifyOauthError("mock error")
+    )
+
+    # Define a mock configuration
+    mock_config = {
+        "username": "test_user",
+        "client_id": "test_client_id",
+        "client_secret": "test_client_secret",
+        "redirect_uri": "http://localhost/",
+    }
+
+    # Mock sys.exit to prevent the test from exiting
+    mock_sys_exit = mocker.patch("sys.exit")
+
+    # Call the function under test and assert sys.exit is called
+    open_spotify_session(mock_config)
+    mock_sys_exit.assert_called_once()