add gemma test

tests/data/test_template.py

@@ -43,21 +43,33 @@ def _check_tokenization(
         assert tokenizer.decode(input_ids) == text
 
 
-def _check_single_template(model_id: str, template_name: str, prompt_str: str, answer_str: str, use_fast: bool):
+def _check_single_template(
+    model_id: str, template_name: str, prompt_str: str, answer_str: str, extra_str: str, use_fast: bool
+):
     tokenizer = AutoTokenizer.from_pretrained(model_id, use_fast=use_fast, token=os.environ.get("HF_TOKEN", None))
-    content_str = tokenizer.apply_chat_template(MESSAGES, tokenize=False).rstrip("\n")  # avoid extra newline
+    content_str = tokenizer.apply_chat_template(MESSAGES, tokenize=False)
-    content_ids = tokenizer.encode(content_str, add_special_tokens=False)
+    content_ids = tokenizer.apply_chat_template(MESSAGES, tokenize=True)
     template = get_template_and_fix_tokenizer(tokenizer, name=template_name)
     prompt_ids, answer_ids = template.encode_oneturn(tokenizer, MESSAGES)
-    assert content_str == prompt_str + answer_str
+    assert content_str == prompt_str + answer_str + extra_str
-    assert content_ids == prompt_ids + answer_ids
+    assert content_ids == prompt_ids + answer_ids + tokenizer.encode(extra_str, add_special_tokens=False)
     _check_tokenization(tokenizer, (prompt_ids, answer_ids), (prompt_str, answer_str))
     return content_ids
 
 
-def _check_template(model_id: str, template_name: str, prompt_str: str, answer_str: str):
+def _check_template(model_id: str, template_name: str, prompt_str: str, answer_str: str, extra_str: str = ""):
-    slow_ids = _check_single_template(model_id, template_name, prompt_str, answer_str, use_fast=False)
+    """
-    fast_ids = _check_single_template(model_id, template_name, prompt_str, answer_str, use_fast=True)
+    Checks template for both the slow tokenizer and the fast tokenizer.
+
+    Args:
+        model_id: the model id on hugging face hub.
+        template_name: the template name.
+        prompt_str: the string corresponding to the prompt part.
+        answer_str: the string corresponding to the answer part.
+        extra_str: the extra string in the jinja template of the original tokenizer.
+    """
+    slow_ids = _check_single_template(model_id, template_name, prompt_str, answer_str, extra_str, use_fast=False)
+    fast_ids = _check_single_template(model_id, template_name, prompt_str, answer_str, extra_str, use_fast=True)
     assert slow_ids == fast_ids
 
 
@@ -107,6 +119,17 @@ def test_jinja_template(use_fast: bool):
     assert tokenizer.apply_chat_template(MESSAGES) == ref_tokenizer.apply_chat_template(MESSAGES)
 
 
+def test_gemma_template():
+    prompt_str = (
+        "<bos><start_of_turn>user\nHow are you<end_of_turn>\n"
+        "<start_of_turn>model\nI am fine!<end_of_turn>\n"
+        "<start_of_turn>user\n你好<end_of_turn>\n"
+        "<start_of_turn>model\n"
+    )
+    answer_str = "很高兴认识你！"
+    _check_template("google/gemma-2-9b-it", "gemma", prompt_str, answer_str, extra_str="<end_of_turn>\n")
+
+
 def test_llama3_template():
     prompt_str = (
         "<|begin_of_text|><|start_header_id|>user<|end_header_id|>\n\nHow are you<|eot_id|>"
@@ -127,7 +150,7 @@ def test_qwen_template():
         "<|im_start|>assistant\n"
     )
     answer_str = "很高兴认识你！<|im_end|>"
-    _check_template("Qwen/Qwen2-7B-Instruct", "qwen", prompt_str, answer_str)
+    _check_template("Qwen/Qwen2-7B-Instruct", "qwen", prompt_str, answer_str, extra_str="\n")
 
 
 @pytest.mark.skip(reason="The fast tokenizer of Yi model is corrupted.")