[Speculators] Move tests + fix integration (#27308)

Signed-off-by: Dipika Sikka <dipikasikka1@gmail.com>
Signed-off-by: Rahul Tuli <rtuli@redhat.com>
Signed-off-by: rahul-tuli <rtuli@redhat.com>
Co-authored-by: Rahul Tuli <rtuli@redhat.com>
Co-authored-by: Robert Shaw <114415538+robertgshaw2-redhat@users.noreply.github.com>

tests/v1/spec_decode/test_speculators_eagle3.py

@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import pytest
+import torch
+
+from vllm.config import SpeculativeConfig
+from vllm.model_executor.models.interfaces import supports_eagle3
+
+
+@pytest.mark.parametrize(
+    "model_path",
+    [
+        pytest.param(
+            "nm-testing/SpeculatorLlama3-1-8B-Eagle3-converted-0717-quantized",
+            id="llama3-eagle3-speculator",
+        ),
+        pytest.param(
+            "nm-testing/Speculator-Qwen3-8B-Eagle3-converted-071-quantized",
+            id="qwen3-eagle3-speculator",
+        ),
+        pytest.param(
+            "nm-testing/Speculator-Qwen3-8B-Eagle3-converted-071-quantized-w4a16",
+            id="qwen3-eagle3-speculator-w4a16-verifier",
+        ),
+    ],
+)
+def test_eagle3_speculators_model(
+    vllm_runner, example_prompts, model_path, monkeypatch
+):
+    """
+    Test Eagle3 speculators models properly initialize speculative decoding.
+
+    This test verifies:
+    1. Eagle3 support is detected for the model
+    2. Speculative config is automatically initialized from embedded config
+    3. The draft model path is correctly set to the speculators model
+    4. Speculative tokens count is valid
+    5. Text generation works with speculative decoding enabled
+    """
+    # Set environment variable for V1 engine serialization
+    monkeypatch.setenv("VLLM_ALLOW_INSECURE_SERIALIZATION", "1")
+
+    with vllm_runner(model_path, dtype=torch.bfloat16) as vllm_model:
+        # Verify Eagle3 support is detected
+        eagle3_supported = vllm_model.apply_model(supports_eagle3)
+        assert eagle3_supported, f"Eagle3 should be supported for {model_path}"
+
+        vllm_config = vllm_model.llm.llm_engine.vllm_config
+
+        assert isinstance(vllm_config.speculative_config, SpeculativeConfig), (
+            "Speculative config should be initialized for speculators model"
+        )
+
+        spec_config = vllm_config.speculative_config
+        assert spec_config.num_speculative_tokens > 0, (
+            f"Expected positive speculative tokens, "
+            f"got {spec_config.num_speculative_tokens}"
+        )
+
+        assert spec_config.model == model_path, (
+            f"Draft model should be {model_path}, got {spec_config.model}"
+        )
+
+        vllm_outputs = vllm_model.generate_greedy(example_prompts, max_tokens=20)
+        assert vllm_outputs, f"No outputs generated for speculators model {model_path}"