[GIT] Add test for batched generation (#21282)

* Add test

* Apply suggestions
Co-authored-by: Niels Rogge <nielsrogge@Nielss-MacBook-Pro.local>

tests/models/git/test_modeling_git.py

@@ -495,3 +495,22 @@ class GitModelIntegrationTest(unittest.TestCase):
         expected_shape = torch.Size((1, 15))
         self.assertEqual(generated_ids.shape, expected_shape)
         self.assertEquals(generated_caption, "what does the front of the bus say at the top? special")
+
+    def test_batched_generation(self):
+        processor = GitProcessor.from_pretrained("microsoft/git-base-coco")
+        model = GitForCausalLM.from_pretrained("microsoft/git-base-coco")
+        model.to(torch_device)
+
+        # create batch of size 2
+        image = Image.open("./tests/fixtures/tests_samples/COCO/000000039769.png")
+        inputs = processor(images=[image, image], return_tensors="pt")
+        pixel_values = inputs.pixel_values.to(torch_device)
+
+        # we have to prepare `input_ids` with the same batch size as `pixel_values`
+        start_token_id = model.config.bos_token_id
+        generated_ids = model.generate(
+            pixel_values=pixel_values, input_ids=torch.tensor([[start_token_id], [start_token_id]]), max_length=50
+        )
+        generated_captions = processor.batch_decode(generated_ids, skip_special_tokens=True)
+
+        self.assertEquals(generated_captions, ["two cats sleeping on a pink blanket next to remotes."] * 2)