Tokenizer kwargs in textgeneration pipe (#28362)

* added args to the pipeline

* added test

* more sensical tests

* fixup

* docs

* typo
;

* docs

* made changes to support named args

* fixed test

* docs update

* styles

* docs

* docs

docs/source/en/preprocessing.md

@@ -216,6 +216,12 @@ array([[1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0],
 </tf>
 </frameworkcontent>
 
+<Tip>
+Different pipelines support tokenizer arguments in their `__call__()` differently. `text-2-text-generation` pipelines support (i.e. pass on)
+only `truncation`. `text-generation` pipelines support `max_length`, `truncation`, `padding` and `add_special_tokens`. 
+In `fill-mask` pipelines, tokenizer arguments can be passed in the `tokenizer_kwargs` argument (dictionary).
+</Tip>
+
 ## Audio
 
 For audio tasks, you'll need a [feature extractor](main_classes/feature_extractor) to prepare your dataset for the model. The feature extractor is designed to extract features from raw audio data, and convert them into tensors.

src/transformers/pipelines/text_generation.py

@@ -104,9 +104,20 @@ class TextGenerationPipeline(Pipeline):
         handle_long_generation=None,
         stop_sequence=None,
         add_special_tokens=False,
+        truncation=None,
+        padding=False,
+        max_length=None,
         **generate_kwargs,
     ):
-        preprocess_params = {"add_special_tokens": add_special_tokens}
+        preprocess_params = {
+            "add_special_tokens": add_special_tokens,
+            "truncation": truncation,
+            "padding": padding,
+            "max_length": max_length,
+        }
+        if max_length is not None:
+            generate_kwargs["max_length"] = max_length
+
         if prefix is not None:
             preprocess_params["prefix"] = prefix
         if prefix:
@@ -208,10 +219,23 @@ class TextGenerationPipeline(Pipeline):
         return super().__call__(text_inputs, **kwargs)
 
     def preprocess(
-        self, prompt_text, prefix="", handle_long_generation=None, add_special_tokens=False, **generate_kwargs
+        self,
+        prompt_text,
+        prefix="",
+        handle_long_generation=None,
+        add_special_tokens=False,
+        truncation=None,
+        padding=False,
+        max_length=None,
+        **generate_kwargs,
     ):
         inputs = self.tokenizer(
-            prefix + prompt_text, padding=False, add_special_tokens=add_special_tokens, return_tensors=self.framework
+            prefix + prompt_text,
+            return_tensors=self.framework,
+            truncation=truncation,
+            padding=padding,
+            max_length=max_length,
+            add_special_tokens=add_special_tokens,
         )
         inputs["prompt_text"] = prompt_text
 

tests/pipelines/test_pipelines_text_generation.py

@@ -90,6 +90,22 @@ class TextGenerationPipelineTests(unittest.TestCase):
                 {"generated_token_ids": ANY(list)},
             ],
         )
+
+        ## -- test tokenizer_kwargs
+        test_str = "testing tokenizer kwargs. using truncation must result in a different generation."
+        output_str, output_str_with_truncation = (
+            text_generator(test_str, do_sample=False, return_full_text=False)[0]["generated_text"],
+            text_generator(
+                test_str,
+                do_sample=False,
+                return_full_text=False,
+                truncation=True,
+                max_length=3,
+            )[0]["generated_text"],
+        )
+        assert output_str != output_str_with_truncation  # results must be different because one hd truncation
+
+        # -- what is the point of this test? padding is hardcoded False in the pipeline anyway
         text_generator.tokenizer.pad_token_id = text_generator.model.config.eos_token_id
         text_generator.tokenizer.pad_token = "<pad>"
         outputs = text_generator(