Asynchronous tokenization (#2879)

tests/tokenization/test_cached_tokenizer.py

@@ -0,0 +1,20 @@
+from copy import deepcopy
+from vllm.transformers_utils.tokenizer import get_cached_tokenizer
+from transformers import AutoTokenizer
+
+
+def test_cached_tokenizer():
+    reference_tokenizer = AutoTokenizer.from_pretrained("gpt2")
+    reference_tokenizer.add_special_tokens({"cls_token": "<CLS>"})
+    reference_tokenizer.add_special_tokens(
+        {"additional_special_tokens": ["<SEP>"]})
+    cached_tokenizer = get_cached_tokenizer(deepcopy(reference_tokenizer))
+
+    assert reference_tokenizer.encode("prompt") == cached_tokenizer.encode(
+        "prompt")
+    assert set(reference_tokenizer.all_special_ids) == set(
+        cached_tokenizer.all_special_ids)
+    assert set(reference_tokenizer.all_special_tokens) == set(
+        cached_tokenizer.all_special_tokens)
+    assert set(reference_tokenizer.all_special_tokens_extended) == set(
+        cached_tokenizer.all_special_tokens_extended)