[SPEC] feat: init adaptive spec params from config (#27493)

Co-authored-by: Qiaolin Yu <liin1211@outlook.com>

test/registered/spec/eagle/test_adaptive_speculative.py

@@ -72,12 +72,6 @@ class TestAdaptiveSpeculativeServer(CustomTestCase):
                     "EAGLE",
                     "--speculative-draft-model-path",
                     cls.draft_model,
-                    "--speculative-num-steps",
-                    "1",
-                    "--speculative-eagle-topk",
-                    "1",
-                    "--speculative-num-draft-tokens",
-                    "2",
                     "--speculative-adaptive",
                     "--speculative-adaptive-config",
                     cls.adaptive_config_path,

test/registered/unit/server_args/test_server_args.py

@@ -528,6 +528,38 @@ class TestNgramExternalSamArgs(CustomTestCase):
         self.assertIn("external-corpus-max-tokens", str(context.exception))
 
 
+class TestAdaptiveSpecArgs(CustomTestCase):
+    def test_adaptive_defaults_to_config_step_when_spec_params_omitted(self):
+        with tempfile.NamedTemporaryFile("w", suffix=".json") as f:
+            json.dump(
+                {
+                    "1": {"candidate_steps": [1, 3, 5]},
+                    "8": {"candidate_steps": [1]},
+                },
+                f,
+            )
+            f.flush()
+
+            args = ServerArgs(model_path="dummy")
+            args.speculative_algorithm = "EAGLE"
+            args.speculative_adaptive = True
+            args.speculative_adaptive_config = f.name
+            args.device = "cuda"
+            args.get_model_config = lambda: SimpleNamespace(
+                hf_config=SimpleNamespace(
+                    architectures=["LlamaForCausalLM"],
+                    get_text_config=lambda: SimpleNamespace(),
+                )
+            )
+
+            handle_speculative_decoding(args)
+
+        self.assertTrue(args.speculative_adaptive)
+        self.assertEqual(args.speculative_eagle_topk, 1)
+        self.assertEqual(args.speculative_num_steps, 3)
+        self.assertEqual(args.speculative_num_draft_tokens, 4)
+
+
 class TestDeepEPWaterfillArgs(CustomTestCase):
     def test_waterfill_enforces_shared_experts_fusion(self):
         server_args = ServerArgs(

test/registered/unit/spec/test_adaptive_spec_params.py

@@ -6,7 +6,6 @@ from sglang.srt.speculative.adaptive_spec_params import (
     AdaptiveSpeculativeParams,
     AdaptiveStepSlot,
     resolve_candidate_steps_from_config,
-    validate_adaptive_initial_steps,
 )
 from sglang.test.ci.ci_register import register_cpu_ci, register_xpu_ci
 
@@ -403,25 +402,5 @@ class TestResolveCandidateSteps(unittest.TestCase):
         self.assertEqual(steps, [1, 3, 5, 7])
 
 
-class TestValidateAdaptiveInitialSteps(unittest.TestCase):
-    def test_accepts_value_from_any_slot(self):
-        with tempfile.NamedTemporaryFile("w", suffix=".json") as f:
-            json.dump(
-                {
-                    "1": {"candidate_steps": [1, 5]},
-                    "8": {"candidate_steps": [1, 3, 7]},
-                },
-                f,
-            )
-            f.flush()
-            # Membership in any slot is enough: 5 lives in the smallest slot,
-            # 7 only in a larger slot -- both accepted.
-            validate_adaptive_initial_steps(5, cfg_path=f.name)
-            validate_adaptive_initial_steps(7, cfg_path=f.name)
-            # 9 is in no slot -> rejected.
-            with self.assertRaises(ValueError):
-                validate_adaptive_initial_steps(9, cfg_path=f.name)
-
-
 if __name__ == "__main__":
     unittest.main()