Fix CI slow tests: ImportError: vLLM is not installed (#4287)

Author: albertvillanova

tests/test_vllm_client_server.py

@@ -22,7 +22,7 @@
 from trl.extras.vllm_client import VLLMClient
 from trl.scripts.vllm_serve import chunk_list
 
-from .testing_utils import TrlTestCase, kill_process, require_3_accelerators
+from .testing_utils import TrlTestCase, kill_process, require_3_accelerators, require_vllm
 
 
 class TestChunkList(TrlTestCase):
@@ -53,6 +53,7 @@ def test_any_dtype(self):
 
 @pytest.mark.slow
 @require_torch_multi_accelerator
+@require_vllm
 class TestVLLMClientServer(TrlTestCase):
     model_id = "Qwen/Qwen2.5-1.5B"
 
@@ -212,6 +213,7 @@ def teardown_class(cls):
 
 @pytest.mark.slow
 @require_3_accelerators
+@require_vllm
 class TestVLLMClientServerTP(TrlTestCase):
     model_id = "Qwen/Qwen2.5-1.5B"
 
@@ -274,6 +276,7 @@ def teardown_class(cls):
 
 @pytest.mark.slow
 @require_3_accelerators
+@require_vllm
 class TestVLLMClientServerDP(TrlTestCase):
     model_id = "Qwen/Qwen2.5-1.5B"
 
@@ -336,6 +339,7 @@ def teardown_class(cls):
 
 @pytest.mark.slow
 @require_torch_multi_accelerator
+@require_vllm
 class TestVLLMClientServerDeviceParameter(TrlTestCase):
     """Test the device parameter functionality in init_communicator."""