[BugFix]Fix eagle draft_model_config and add tests (#31753)

Signed-off-by: Xingyu Liu <charlotteliu12x@gmail.com>

tests/test_config.py

@@ -13,8 +13,10 @@ from vllm.compilation.backends import VllmBackend
 from vllm.config import (
     CompilationConfig,
     ModelConfig,
+    ParallelConfig,
     PoolerConfig,
     SchedulerConfig,
+    SpeculativeConfig,
     VllmConfig,
     update_config,
 )
@@ -1105,3 +1107,23 @@ def test_needs_dp_coordination(
     vllm_config = VllmConfig(model_config=model_config, parallel_config=parallel_config)
 
     assert vllm_config.needs_dp_coordinator == expected_needs_coordinator
+
+
+def test_eagle_draft_model_config():
+    """Test that EagleDraft model config is correctly set."""
+    target_model_config = ModelConfig(
+        "meta-llama/Meta-Llama-3-8B-Instruct", trust_remote_code=True
+    )
+    speculative_config = SpeculativeConfig(
+        model="yuhuili/EAGLE-LLaMA3-Instruct-8B",
+        num_speculative_tokens=1,
+        target_model_config=target_model_config,
+        target_parallel_config=ParallelConfig(),
+    )
+    draft_model_config = speculative_config.draft_model_config
+    assert draft_model_config.hf_config.architectures == ["EagleLlamaForCausalLM"]
+    assert draft_model_config.hf_text_config.architectures == ["EagleLlamaForCausalLM"]
+    assert draft_model_config.hf_config.model_type == "eagle"
+    assert draft_model_config.hf_text_config.model_type == "eagle"
+    assert draft_model_config.architectures == ["EagleLlamaForCausalLM"]
+    assert draft_model_config.architecture == "EagleLlamaForCausalLM"