add a template to add missing tokenization test (#16553)

* add a template to add missing tokenization test

* add cookiecutter setting

* improve doc

* Update templates/adding_a_missing_tokenization_test/README.md

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

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

templates/adding_a_missing_tokenization_test/cookiecutter-template-{{cookiecutter.modelname}}/test_tokenization_{{cookiecutter.lowercase_modelname}}.py

@@ -0,0 +1,78 @@
+# coding=utf-8
+# Copyright 2022 {{cookiecutter.authors}}. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+""" Testing suite for the {{cookiecutter.modelname}} tokenizer. """
+
+
+import unittest
+
+{% if cookiecutter.has_slow_class == "True" and  cookiecutter.has_fast_class == "True" -%}
+from transformers import {{cookiecutter.camelcase_modelname}}Tokenizer, {{cookiecutter.camelcase_modelname}}TokenizerFast
+{% elif  cookiecutter.has_slow_class == "True" -%}
+from transformers import {{cookiecutter.camelcase_modelname}}Tokenizer
+{% elif  cookiecutter.has_fast_class == "True" -%}
+from transformers import {{cookiecutter.camelcase_modelname}}TokenizerFast
+{% endif -%}
+{% if cookiecutter.has_fast_class == "True" and  cookiecutter.slow_tokenizer_use_sentencepiece == "True" -%}
+from transformers.testing_utils import require_sentencepiece, require_tokenizers
+from ..test_tokenization_common import TokenizerTesterMixin
+
+
+@require_sentencepiece
+@require_tokenizers
+{% elif  cookiecutter.slow_tokenizer_use_sentencepiece == "True" -%}
+from transformers.testing_utils import require_sentencepiece
+from ..test_tokenization_common import TokenizerTesterMixin
+
+
+@require_sentencepiece
+{% elif  cookiecutter.has_fast_class == "True" -%}
+from transformers.testing_utils import require_tokenizers
+from ..test_tokenization_common import TokenizerTesterMixin
+
+
+@require_tokenizers
+{% else -%}
+from ..test_tokenization_common import TokenizerTesterMixin
+
+
+{% endif -%}
+class {{cookiecutter.camelcase_modelname}}TokenizationTest(TokenizerTesterMixin, unittest.TestCase):
+    {% if cookiecutter.has_slow_class == "True" -%}
+    tokenizer_class = {{cookiecutter.camelcase_modelname}}Tokenizer
+    test_slow_tokenizer = True
+    {% else -%}
+    tokenizer_class = None
+    test_slow_tokenizer = False
+    {% endif -%}
+    {% if cookiecutter.has_fast_class == "True" -%}
+    rust_tokenizer_class = {{cookiecutter.camelcase_modelname}}TokenizerFast
+    test_rust_tokenizer = True
+    {% else -%}
+    rust_tokenizer_class = None
+    test_rust_tokenizer = False
+    {% endif -%}
+    {% if  cookiecutter.slow_tokenizer_use_sentencepiece == "True" -%}
+    test_sentencepiece = True
+    {% endif -%}
+    # TODO: Check in `TokenizerTesterMixin` if other attributes need to be changed
+    def setUp(self):
+        super().setUp()
+
+        raise NotImplementedError(
+            "Here you have to implement the saving of a toy tokenizer in "
+            "`self.tmpdirname`."
+        )
+
+    # TODO: add tests with hard-coded target values