Update `PreTrainedTokenizerBase` to check/handle batch length for `text_pair` parameter (#11486)

* Update tokenization_utils_base.py

* add assertion

* check batch len

* Update src/transformers/tokenization_utils_base.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* add error message
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

src/transformers/tokenization_utils_base.py

@@ -2279,6 +2279,14 @@ class PreTrainedTokenizerBase(SpecialTokensMixin, PushToHubMixin):
         )
 
         if is_batched:
+            if isinstance(text_pair, str):
+                raise TypeError(
+                    "when tokenizing batches of text, `text_pair` must be a list or tuple with the same length as `text`."
+                )
+            if text_pair is not None and len(text) != len(text_pair):
+                raise ValueError(
+                    f"batch length of `text`: {len(text)} does not match batch length of `text_pair`: {len(text_pair)}."
+                )
             batch_text_or_text_pairs = list(zip(text, text_pair)) if text_pair is not None else text
             return self.batch_encode_plus(
                 batch_text_or_text_pairs=batch_text_or_text_pairs,