Adding some quality of life for pipeline function. (#14322)

* Adding some quality of life for `pipeline` function.

* Update docs/source/main_classes/pipelines.rst

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

* Update src/transformers/pipelines/__init__.py

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

* Improve the tests.

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

tests/test_pipelines_common.py

@@ -29,8 +29,10 @@ from transformers import (
     AutoTokenizer,
     IBertConfig,
     RobertaConfig,
+    TextClassificationPipeline,
     pipeline,
 )
+from transformers.pipelines import get_task
 from transformers.pipelines.base import _pad
 from transformers.testing_utils import is_pipeline_test, require_torch
 
@@ -261,6 +263,29 @@ class CommonPipelineTest(unittest.TestCase):
         for output in text_classifier(dataset):
             self.assertEqual(output, {"label": ANY(str), "score": ANY(float)})
 
+    @require_torch
+    def test_check_task_auto_inference(self):
+        pipe = pipeline(model="Narsil/tiny-distilbert-sequence-classification")
+
+        self.assertIsInstance(pipe, TextClassificationPipeline)
+
+    @require_torch
+    def test_pipeline_override(self):
+        class MyPipeline(TextClassificationPipeline):
+            pass
+
+        text_classifier = pipeline(model="Narsil/tiny-distilbert-sequence-classification", pipeline_class=MyPipeline)
+
+        self.assertIsInstance(text_classifier, MyPipeline)
+
+    def test_check_task(self):
+        task = get_task("gpt2")
+        self.assertEqual(task, "text-generation")
+
+        with self.assertRaises(RuntimeError):
+            # Wrong framework
+            get_task("espnet/siddhana_slurp_entity_asr_train_asr_conformer_raw_en_word_valid.acc.ave_10best")
+
 
 @is_pipeline_test
 class PipelinePadTest(unittest.TestCase):