Torchscript test for ConvBERT (#13352)

* Torchscript test for ConvBERT

* Apply suggestions from code review

tests/test_modeling_convbert.py

@@ -13,14 +13,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """ Testing suite for the PyTorch ConvBERT model. """
-
-
+import os
+import tempfile
 import unittest
 
 from tests.test_modeling_common import floats_tensor
 from transformers import ConvBertConfig, is_torch_available
 from transformers.models.auto import get_values
-from transformers.testing_utils import require_torch, slow, torch_device
+from transformers.testing_utils import require_torch, require_torch_gpu, slow, torch_device
 
 from .test_configuration_common import ConfigTester
 from .test_modeling_common import ModelTesterMixin, ids_tensor, random_attention_mask
@@ -416,6 +416,29 @@ class ConvBertModelTest(ModelTesterMixin, unittest.TestCase):
                     [self.model_tester.num_attention_heads / 2, encoder_seq_length, encoder_key_length],
                 )
 
+    @slow
+    @require_torch_gpu
+    def test_torchscript_device_change(self):
+        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
+        for model_class in self.all_model_classes:
+
+            # ConvBertForMultipleChoice behaves incorrectly in JIT environments.
+            if model_class == ConvBertForMultipleChoice:
+                return
+
+            config.torchscript = True
+            model = model_class(config=config)
+
+            inputs_dict = self._prepare_for_class(inputs_dict, model_class)
+            traced_model = torch.jit.trace(
+                model, (inputs_dict["input_ids"].to("cpu"), inputs_dict["attention_mask"].to("cpu"))
+            )
+
+            with tempfile.TemporaryDirectory() as tmp:
+                torch.jit.save(traced_model, os.path.join(tmp, "traced_model.pt"))
+                loaded = torch.jit.load(os.path.join(tmp, "bert.pt"), map_location=torch_device)
+                loaded(inputs_dict["input_ids"].to(torch_device), inputs_dict["attention_mask"].to(torch_device))
+
 
 @require_torch
 class ConvBertModelIntegrationTest(unittest.TestCase):