Support spec decoding when LoRA is applied to target model (#12903)

test/srt/lora/test_lora_spec_decoding.py

@@ -0,0 +1,71 @@
+# Copyright 2023-2025 SGLang Team
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+import multiprocessing as mp
+import unittest
+
+from utils import (
+    CI_MULTI_LORA_MODELS,
+    LoRAAdaptor,
+    LoRAModelCase,
+    run_lora_multiple_batch_on_model_cases,
+)
+
+from sglang.test.test_utils import CustomTestCase
+
+LORA_MODELS_QWEN3 = [
+    LoRAModelCase(
+        base="Qwen/Qwen3-4B",
+        adaptors=[
+            LoRAAdaptor(
+                name="nissenj/Qwen3-4B-lora-v2",
+                prefill_tolerance=3e-1,
+            ),
+            LoRAAdaptor(
+                name="y9760210/Qwen3-4B-lora_model",
+                prefill_tolerance=3e-1,
+            ),
+        ],
+        max_loras_per_batch=2,
+    ),
+]
+
+
+class TestLoRASpecDecoding(CustomTestCase):
+    def test_qwen(self):
+        run_lora_multiple_batch_on_model_cases(
+            LORA_MODELS_QWEN3,
+            attention_backend="triton",
+            use_spec_decoding=True,
+            disable_cuda_graph=True,
+            enable_deterministic_inference=True,
+        )
+
+    def test_llama(self):
+        run_lora_multiple_batch_on_model_cases(
+            CI_MULTI_LORA_MODELS,
+            attention_backend="triton",
+            use_spec_decoding=True,
+            disable_cuda_graph=True,
+            enable_deterministic_inference=True,
+        )
+
+
+if __name__ == "__main__":
+    try:
+        mp.set_start_method("spawn")
+    except RuntimeError:
+        pass
+
+    unittest.main(warnings="ignore")