Add tests for fast tokenizers

tests/test_tokenization_bert.py

@@ -21,6 +21,7 @@ from transformers.tokenization_bert import (
     VOCAB_FILES_NAMES,
     BasicTokenizer,
     BertTokenizer,
+    BertTokenizerFast,
     WordpieceTokenizer,
     _is_control,
     _is_punctuation,
@@ -34,6 +35,7 @@ from .utils import slow
 class BertTokenizationTest(TokenizerTesterMixin, unittest.TestCase):
 
     tokenizer_class = BertTokenizer
+    test_rust_tokenizer = True
 
     def setUp(self):
         super(BertTokenizationTest, self).setUp()
@@ -60,6 +62,9 @@ class BertTokenizationTest(TokenizerTesterMixin, unittest.TestCase):
     def get_tokenizer(self, **kwargs):
         return BertTokenizer.from_pretrained(self.tmpdirname, **kwargs)
 
+    def get_rust_tokenizer(self, **kwargs):
+        return BertTokenizerFast.from_pretrained(self.tmpdirname, **kwargs)
+
     def get_input_output_texts(self):
         input_text = "UNwant\u00E9d,running"
         output_text = "unwanted, running"
@@ -72,6 +77,28 @@ class BertTokenizationTest(TokenizerTesterMixin, unittest.TestCase):
         self.assertListEqual(tokens, ["un", "##want", "##ed", ",", "runn", "##ing"])
         self.assertListEqual(tokenizer.convert_tokens_to_ids(tokens), [7, 4, 5, 10, 8, 9])
 
+    def test_rust_and_python_full_tokenizers(self):
+        if not self.test_rust_tokenizer:
+            return
+
+        tokenizer = self.get_tokenizer()
+        rust_tokenizer = self.get_rust_tokenizer(add_special_tokens=False)
+
+        sequence = u"UNwant\u00E9d,running"
+
+        tokens = tokenizer.tokenize(sequence)
+        rust_tokens = rust_tokenizer.tokenize(sequence)
+        self.assertListEqual(tokens, rust_tokens)
+
+        ids = tokenizer.encode(sequence, add_special_tokens=False)
+        rust_ids = rust_tokenizer.encode(sequence)
+        self.assertListEqual(ids, rust_ids)
+
+        rust_tokenizer = self.get_rust_tokenizer()
+        ids = tokenizer.encode(sequence)
+        rust_ids = rust_tokenizer.encode(sequence)
+        self.assertListEqual(ids, rust_ids)
+
     def test_chinese(self):
         tokenizer = BasicTokenizer()