[Diffusion] Unify diffusion request identity on request_id (#3744)

Signed-off-by: jader <yjader@foxmail.com>

tests/diffusion/test_diffusion_request.py

@@ -5,7 +5,7 @@ import random
 
 import pytest
 
-from vllm_omni.diffusion.request import OmniDiffusionRequest
+from vllm_omni.diffusion.request import DUMMY_DIFFUSION_REQUEST_ID, OmniDiffusionRequest
 from vllm_omni.inputs.data import OmniDiffusionSamplingParams
 
 pytestmark = [pytest.mark.core_model, pytest.mark.diffusion, pytest.mark.cpu]
@@ -15,9 +15,53 @@ def _make_request() -> OmniDiffusionRequest:
     return OmniDiffusionRequest(
         prompts=[{"prompt": "a cup of coffee on a table"}],
         sampling_params=OmniDiffusionSamplingParams(num_inference_steps=1),
+        request_id="request-test",
     )
 
 
+def test_request_id_is_required():
+    with pytest.raises(TypeError, match="request_id"):
+        OmniDiffusionRequest(
+            prompts=[{"prompt": "a cup of coffee on a table"}],
+            sampling_params=OmniDiffusionSamplingParams(num_inference_steps=1),
+        )
+
+
+def test_request_ids_identity_list_is_removed():
+    req = _make_request()
+
+    assert req.request_id == "request-test"
+    assert not hasattr(req, "request_ids")
+
+
+def test_request_id_must_be_non_empty():
+    with pytest.raises(ValueError, match="request_id must be a non-empty string"):
+        OmniDiffusionRequest(
+            prompts=[{"prompt": "a cup of coffee on a table"}],
+            sampling_params=OmniDiffusionSamplingParams(num_inference_steps=1),
+            request_id="",
+        )
+
+
+def test_dummy_run_request_is_identified_by_reserved_request_id():
+    req = OmniDiffusionRequest(
+        prompts=[{"prompt": "dummy run"}],
+        sampling_params=OmniDiffusionSamplingParams(num_inference_steps=1),
+        request_id=DUMMY_DIFFUSION_REQUEST_ID,
+    )
+
+    assert req.is_dummy_run()
+    assert OmniDiffusionRequest.is_dummy_run_request_id(DUMMY_DIFFUSION_REQUEST_ID)
+
+
+def test_non_dummy_request_is_not_identified_as_dummy_run():
+    req = _make_request()
+
+    assert not req.is_dummy_run()
+    assert not OmniDiffusionRequest.is_dummy_run_request_id(req.request_id)
+    assert not OmniDiffusionRequest.is_dummy_run_request_id(None)
+
+
 def test_tp_seed_same_across_ranks_and_varies_across_requests():
     random.seed(0)
     n_requests = 5