Fix failing test on Windows Platform (huggingface#11589)

* add separator for windows

* fixes test_is_copy_consistent on Windows

* fixing writing encoding issue on extended test (for Windows)

* resolving comments

examples/pytorch/translation/run_translation.py

@@ -571,7 +571,7 @@ def compute_metrics(eval_preds):
                 )
                 predictions = [pred.strip() for pred in predictions]
                 output_prediction_file = os.path.join(training_args.output_dir, "generated_predictions.txt")
-                with open(output_prediction_file, "w") as writer:
+                with open(output_prediction_file, "w", encoding="utf-8") as writer:
                     writer.write("\n".join(predictions))
 
     if training_args.push_to_hub:

tests/test_tokenization_wav2vec2.py

@@ -231,7 +231,7 @@ def test_save_pretrained(self):
         tokenizer_files = tokenizer.save_pretrained(tmpdirname2)
         self.assertSequenceEqual(
             sorted(tuple(VOCAB_FILES_NAMES.values()) + ("special_tokens_map.json", "added_tokens.json")),
-            sorted(tuple(x.split("/")[-1] for x in tokenizer_files)),
+            sorted(tuple(x.split(os.path.sep)[-1] for x in tokenizer_files)),
         )
 
         # Checks everything loads correctly in the same way

tests/test_utils_check_copies.py

@@ -70,7 +70,7 @@ def check_copy_consistency(self, comment, class_name, class_code, overwrite_resu
             expected = comment + f"\nclass {class_name}(nn.Module):\n" + overwrite_result
         code = black.format_str(code, mode=black.FileMode([black.TargetVersion.PY35], line_length=119))
         fname = os.path.join(self.transformer_dir, "new_code.py")
-        with open(fname, "w") as f:
+        with open(fname, "w", newline="\n") as f:
             f.write(code)
         if overwrite_result is None:
             self.assertTrue(len(check_copies.is_copy_consistent(fname)) == 0)