[Spec Decode][CI] Add e2e test for `examples/spec_decode.py` and prevent...

[Spec Decode][CI] Add e2e test for `examples/spec_decode.py` and prevent breaking Acceptance Length (#24531)
Signed-off-by: Ekagra Ranjan <3116519+ekagra-ranjan@users.noreply.github.com>
Co-authored-by: Roger Wang <hey@rogerw.io>

.buildkite/test-pipeline.yaml

@@ -329,6 +329,8 @@ steps:
     - python3 offline_inference/basic/classify.py
     - python3 offline_inference/basic/embed.py
     - python3 offline_inference/basic/score.py
+    - python3 offline_inference/spec_decode.py --test --method eagle --num_spec_tokens 3 --dataset-name hf --dataset-path philschmid/mt-bench --num-prompts 80 --temp 0 --top-p 1.0 --top-k -1 --tp 1 --enable-chunked-prefill --max-model-len 2048
+    - python3 offline_inference/spec_decode.py --test --method eagle3 --num_spec_tokens 3 --dataset-name hf --dataset-path philschmid/mt-bench --num-prompts 80 --temp 0 --top-p 1.0 --top-k -1 --tp 1 --enable-chunked-prefill --max-model-len 2048
 
 - label: Platform Tests (CUDA) # 4min
   timeout_in_minutes: 15

examples/offline_inference/spec_decode.py

@@ -49,6 +49,7 @@ def get_custom_mm_prompts(num_prompts):
 def parse_args():
     parser = FlexibleArgumentParser()
     add_dataset_parser(parser)
+    parser.add_argument("--test", action="store_true")
     parser.add_argument(
         "--method",
         type=str,
@@ -60,6 +61,7 @@ def parse_args():
     parser.add_argument("--tp", type=int, default=1)
     parser.add_argument("--enforce-eager", action="store_true")
     parser.add_argument("--enable-chunked-prefill", action="store_true")
+    parser.add_argument("--max-model-len", type=int, default=16384)
     parser.add_argument("--temp", type=float, default=0)
     parser.add_argument("--top-p", type=float, default=1.0)
     parser.add_argument("--top-k", type=int, default=-1)
@@ -71,8 +73,7 @@ def parse_args():
     return parser.parse_args()
 
 
-def main():
-    args = parse_args()
+def main(args):
     args.endpoint_type = "openai-chat"
 
     model_dir = args.model_dir
@@ -134,7 +135,7 @@ def main():
         gpu_memory_utilization=0.8,
         speculative_config=speculative_config,
         disable_log_stats=False,
-        max_model_len=16384,
+        max_model_len=args.max_model_len,
         limit_mm_per_prompt={"image": 5},
         disable_chunked_mm_input=True,
     )
@@ -198,6 +199,39 @@ def main():
         acceptance_rate = acceptance_counts[i] / num_drafts if num_drafts > 0 else 0
         print(f"acceptance at token {i}: {acceptance_rate:.2f}")
 
+    return acceptance_length
+
 
 if __name__ == "__main__":
-    main()
+    args = parse_args()
+    acceptance_length = main(args)
+
+    if args.test:
+        # takes ~30s to run on 1xH100
+        assert args.method in ["eagle", "eagle3"]
+        assert args.tp == 1
+        assert args.num_spec_tokens == 3
+        assert args.dataset_name == "hf"
+        assert args.dataset_path == "philschmid/mt-bench"
+        assert args.num_prompts == 80
+        assert args.temp == 0
+        assert args.top_p == 1.0
+        assert args.top_k == -1
+        assert args.enable_chunked_prefill
+
+        # check acceptance length is within 2% of expected value
+        rtol = 0.02
+        expected_acceptance_length = 2.296 if args.method == "eagle" else 2.811
+
+        assert (
+            acceptance_length <= (1 + rtol) * expected_acceptance_length
+            and acceptance_length >= (1 - rtol) * expected_acceptance_length
+        ), (
+            f"acceptance_length {acceptance_length} is not "
+            f"within {rtol * 100}% of {expected_acceptance_length}"
+        )
+
+        print(
+            f"Test passed! Expected AL: "
+            f"{expected_acceptance_length}, got {acceptance_length}"
+        )