test: add pytest tests for authorized client connection handling

Author: chigwell

tests/test_runner.py

@@ -0,0 +1,40 @@
+import pytest
+
+from telegram_mcp import runner
+
+
+class _FakeClient:
+    def __init__(self, *, authorized: bool):
+        self.authorized = authorized
+        self.connected = False
+        self.started = False
+
+    async def connect(self):
+        self.connected = True
+
+    async def is_user_authorized(self):
+        return self.authorized
+
+    async def start(self):
+        self.started = True
+
+
+@pytest.mark.asyncio
+async def test_connect_authorized_client_uses_existing_session_without_interactive_start():
+    client = _FakeClient(authorized=True)
+
+    await runner._connect_authorized_client("default", client)
+
+    assert client.connected is True
+    assert client.started is False
+
+
+@pytest.mark.asyncio
+async def test_connect_authorized_client_rejects_unauthorized_session():
+    client = _FakeClient(authorized=False)
+
+    with pytest.raises(RuntimeError, match="Interactive phone login is disabled"):
+        await runner._connect_authorized_client("default", client)
+
+    assert client.connected is True
+    assert client.started is False