[V1][Spec Decode] Eagle Model loading (#16035)

Signed-off-by: LiuXiaoxuanPKU <lilyliupku@gmail.com>

tests/v1/e2e/test_spec_decode.py

@@ -53,6 +53,11 @@ def model_name():
     return "meta-llama/Meta-Llama-3-8B-Instruct"
 
 
+@pytest.fixture
+def eagle_model_name():
+    return "yuhuili/EAGLE-LLaMA3-Instruct-8B"
+
+
 def test_ngram_correctness(
     monkeypatch: pytest.MonkeyPatch,
     test_prompts: list[list[dict[str, Any]]],
@@ -95,3 +100,47 @@ def test_ngram_correctness(
         # Upon failure, inspect the outputs to check for inaccuracy.
         assert matches > int(0.7 * len(ref_outputs))
         del spec_llm
+
+
+def test_eagle_correctness(
+    monkeypatch: pytest.MonkeyPatch,
+    test_prompts: list[list[dict[str, Any]]],
+    sampling_config: SamplingParams,
+    model_name: str,
+    eagle_model_name: str,
+):
+    '''
+    Compare the outputs of a original LLM and a speculative LLM
+    should be the same when using eagle speculative decoding.
+    '''
+    with monkeypatch.context() as m:
+        m.setenv("VLLM_USE_V1", "1")
+
+        ref_llm = LLM(model=model_name, max_model_len=1024)
+        ref_outputs = ref_llm.chat(test_prompts, sampling_config)
+        del ref_llm
+
+        spec_llm = LLM(
+            model=model_name,
+            speculative_config={
+                "method": "eagle",
+                "model": eagle_model_name,
+                "num_speculative_tokens": 3,
+            },
+            max_model_len=1024,
+        )
+        spec_outputs = spec_llm.chat(test_prompts, sampling_config)
+        matches = 0
+        misses = 0
+        for ref_output, spec_output in zip(ref_outputs, spec_outputs):
+            if ref_output.outputs[0].text == spec_output.outputs[0].text:
+                matches += 1
+            else:
+                misses += 1
+                print(f"ref_output: {ref_output.outputs[0].text}")
+                print(f"spec_output: {spec_output.outputs[0].text}")
+
+        # Heuristic: expect at least 70% of the prompts to match exactly
+        # Upon failure, inspect the outputs to check for inaccuracy.
+        assert matches > int(0.7 * len(ref_outputs))
+        del spec_llm