model: serve bare Qwen3Model backbone natively as an embedding model (#32457)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-27 15:49:58 +08:00
parent 169fc1e20c
commit 9a0bd24bed
4 changed files with 192 additions and 0 deletions
@@ -0,0 +1,61 @@
+"""Unit tests for native registration of the bare ``Qwen3Model`` embedding arch.
+
+Checkpoints such as ``microsoft/harrier-oss-v1-0.6b`` declare
+``architectures=["Qwen3Model"]`` (a bare Qwen3 backbone). These must resolve to
+the native SGLang implementation (``sglang.srt.models.qwen3_embedding.Qwen3Model``)
+and be served as an embedding model, NOT fall back to the Transformers backend.
+"""
+
+from sglang.test.ci.ci_register import register_cpu_ci
+
+register_cpu_ci(est_time=10, suite="base-a-test-cpu")
+
+import unittest
+
+from sglang.srt.configs.model_config import is_generation_model
+from sglang.test.test_utils import CustomTestCase
+
+
+class TestQwen3ModelEmbeddingRegistration(CustomTestCase):
+    def test_entry_class_is_native_qwen3model(self):
+        """The bare arch string maps to a native EntryClass named 'Qwen3Model'."""
+        from sglang.srt.models import qwen3_embedding
+
+        entry = qwen3_embedding.EntryClass
+        self.assertEqual(entry.__name__, "Qwen3Model")
+        self.assertEqual(entry.__module__, "sglang.srt.models.qwen3_embedding")
+        # It carries a LAST-token / normalized pooler, i.e. an embedding head.
+        self.assertTrue(hasattr(entry, "forward"))
+        self.assertTrue(hasattr(entry, "load_weights"))
+
+    def test_registry_resolves_native_not_transformers_fallback(self):
+        """ModelRegistry resolves 'Qwen3Model' to the native class, not the
+        TransformersForCausalLM fallback."""
+        from sglang.srt.models.registry import ModelRegistry
+
+        model_cls, resolved_arch = ModelRegistry.resolve_model_cls("Qwen3Model")
+        self.assertEqual(resolved_arch, "Qwen3Model")
+        self.assertEqual(model_cls.__name__, "Qwen3Model")
+        self.assertEqual(model_cls.__module__, "sglang.srt.models.qwen3_embedding")
+        self.assertNotIn("Transformers", model_cls.__name__)
+
+    def test_bare_qwen3model_classified_as_embedding(self):
+        """'Qwen3Model' is non-generative regardless of the --is-embedding flag."""
+        self.assertFalse(is_generation_model(["Qwen3Model"]))
+        self.assertFalse(is_generation_model(["Qwen3Model"], is_embedding=False))
+        self.assertFalse(is_generation_model(["Qwen3Model"], is_embedding=True))
+
+    def test_existing_qwen3_archs_unaffected(self):
+        """The generative / classification archs keep their prior behavior."""
+        # Qwen3ForCausalLM is generative by default, embedding only with the flag
+        # (this is how Qwen3-Embedding-0.6B is served).
+        self.assertTrue(is_generation_model(["Qwen3ForCausalLM"]))
+        self.assertTrue(is_generation_model(["Qwen3ForCausalLM"], is_embedding=False))
+        self.assertFalse(is_generation_model(["Qwen3ForCausalLM"], is_embedding=True))
+        # Sequence-classification / reward archs stay non-generative.
+        self.assertFalse(is_generation_model(["Qwen3ForSequenceClassification"]))
+        self.assertFalse(is_generation_model(["Qwen3ForRewardModel"]))
+
+
+if __name__ == "__main__":
+    unittest.main()