test_modeling_tf_gpt2.py

# coding=utf-8
# Copyright 2020 The HuggingFace Team. 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.

from __future__ import annotations

import unittest

from transformers import GPT2Config, is_tf_available
from transformers.testing_utils import require_tf, require_tf2onnx, slow

from ...test_configuration_common import ConfigTester
from ...test_modeling_tf_common import TFModelTesterMixin, floats_tensor, ids_tensor, random_attention_mask
from ...test_pipeline_mixin import PipelineTesterMixin
from ...utils.test_modeling_tf_core import TFCoreModelTesterMixin


if is_tf_available():
    import tensorflow as tf

    from transformers import GPT2Tokenizer
    from transformers.models.gpt2.modeling_tf_gpt2 import (
        TF_GPT2_PRETRAINED_MODEL_ARCHIVE_LIST,
        TFGPT2DoubleHeadsModel,
        TFGPT2ForSequenceClassification,
        TFGPT2LMHeadModel,
        TFGPT2Model,
    )
    from transformers.tf_utils import shape_list


class TFGPT2ModelTester:
    def __init__(
        self,
        parent,
    ):
        self.parent = parent
        self.batch_size = 13
        self.seq_length = 7
        self.is_training = True
        self.use_token_type_ids = True
        self.use_input_mask = True
        self.use_labels = True
        self.use_mc_token_ids = True
        self.vocab_size = 99
        self.hidden_size = 32
        self.num_hidden_layers = 5
        self.num_attention_heads = 4
        self.intermediate_size = 37
        self.hidden_act = "gelu"
        self.hidden_dropout_prob = 0.1
        self.attention_probs_dropout_prob = 0.1
        self.max_position_embeddings = 512
        self.type_vocab_size = 16
        self.type_sequence_label_size = 2
        self.initializer_range = 0.02
        self.num_labels = 3
        self.num_choices = 4
        self.scope = None
        self.bos_token_id = self.vocab_size - 1
        self.eos_token_id = self.vocab_size - 1
        self.pad_token_id = self.vocab_size - 1

    def prepare_config_and_inputs(self):
        input_ids = ids_tensor([self.batch_size, self.seq_length], self.vocab_size)

        input_mask = None
        if self.use_input_mask:
            input_mask = random_attention_mask([self.batch_size, self.seq_length])

        token_type_ids = None
        if self.use_token_type_ids:
            token_type_ids = ids_tensor([self.batch_size, self.seq_length], self.type_vocab_size)

        mc_token_ids = None
        if self.use_mc_token_ids:
            mc_token_ids = ids_tensor([self.batch_size, self.num_choices], self.seq_length)

        sequence_labels = None
        token_labels = None
        choice_labels = None
        if self.use_labels:
            sequence_labels = ids_tensor([self.batch_size], self.type_sequence_label_size)
            token_labels = ids_tensor([self.batch_size, self.seq_length], self.num_labels)
            choice_labels = ids_tensor([self.batch_size], self.num_choices)

        config = GPT2Config(
            vocab_size=self.vocab_size,
            n_embd=self.hidden_size,
            n_layer=self.num_hidden_layers,
            n_head=self.num_attention_heads,
            # intermediate_size=self.intermediate_size,
            # hidden_act=self.hidden_act,
            # hidden_dropout_prob=self.hidden_dropout_prob,
            # attention_probs_dropout_prob=self.attention_probs_dropout_prob,
            n_positions=self.max_position_embeddings,
            # type_vocab_size=self.type_vocab_size,
            # initializer_range=self.initializer_range
            bos_token_id=self.bos_token_id,
            eos_token_id=self.eos_token_id,
            pad_token_id=self.pad_token_id,
            return_dict=True,
        )

        head_mask = ids_tensor([self.num_hidden_layers, self.num_attention_heads], 2)

        return (
            config,
            input_ids,
            input_mask,
            head_mask,
            token_type_ids,
            mc_token_ids,
            sequence_labels,
            token_labels,
            choice_labels,
        )

    def prepare_config_and_inputs_for_decoder(self):
        (
            config,
            input_ids,
            input_mask,
            head_mask,
            token_type_ids,
            mc_token_ids,
            sequence_labels,
            token_labels,
            choice_labels,
        ) = self.prepare_config_and_inputs()

        encoder_hidden_states = floats_tensor([self.batch_size, self.seq_length, self.hidden_size])
        encoder_attention_mask = ids_tensor([self.batch_size, self.seq_length], vocab_size=2)

        return (
            config,
            input_ids,
            input_mask,
            head_mask,
            token_type_ids,
            sequence_labels,
            token_labels,
            choice_labels,
            encoder_hidden_states,
            encoder_attention_mask,
        )

    def create_and_check_gpt2_model(self, config, input_ids, input_mask, head_mask, token_type_ids, *args):
        model = TFGPT2Model(config=config)
        inputs = {
            "input_ids": input_ids,
            "attention_mask": input_mask,
            "token_type_ids": token_type_ids,
        }
        result = model(inputs)

        inputs = [input_ids, None, input_mask]  # None is the input for 'past'
        result = model(inputs)

        result = model(input_ids)

        self.parent.assertEqual(result.last_hidden_state.shape, (self.batch_size, self.seq_length, self.hidden_size))

    def create_and_check_gpt2_model_past(self, config, input_ids, input_mask, head_mask, token_type_ids, *args):
        model = TFGPT2Model(config=config)

        # first forward pass
        outputs = model(input_ids, token_type_ids=token_type_ids, use_cache=True)
        outputs_use_cache_conf = model(input_ids, token_type_ids=token_type_ids)
        outputs_no_past = model(input_ids, token_type_ids=token_type_ids, use_cache=False)

        self.parent.assertTrue(len(outputs) == len(outputs_use_cache_conf))
        self.parent.assertTrue(len(outputs) == len(outputs_no_past) + 1)

        output, past_key_values = outputs.to_tuple()

        # create hypothetical next token and extent to next_input_ids
        next_tokens = ids_tensor((self.batch_size, 1), config.vocab_size)
        next_token_types = ids_tensor([self.batch_size, 1], self.type_vocab_size)

        # append to next input_ids and token_type_ids
        next_input_ids = tf.concat([input_ids, next_tokens], axis=-1)
        next_token_type_ids = tf.concat([token_type_ids, next_token_types], axis=-1)

        output_from_no_past = model(next_input_ids, token_type_ids=next_token_type_ids)["last_hidden_state"]
        output_from_past = model(next_tokens, token_type_ids=next_token_types, past_key_values=past_key_values)[
            "last_hidden_state"
        ]

        # select random slice
        random_slice_idx = int(ids_tensor((1,), shape_list(output_from_past)[-1]))
        output_from_no_past_slice = output_from_no_past[:, -1, random_slice_idx]
        output_from_past_slice = output_from_past[:, 0, random_slice_idx]

        # test that outputs are equal for slice
        tf.debugging.assert_near(output_from_past_slice, output_from_no_past_slice, rtol=1e-6)

    def create_and_check_gpt2_model_attention_mask_past(
        self, config, input_ids, input_mask, head_mask, token_type_ids, *args
    ):
        model = TFGPT2Model(config=config)

        # create attention mask
        half_seq_length = self.seq_length // 2
        attn_mask_begin = tf.ones((self.batch_size, half_seq_length), dtype=tf.int32)
        attn_mask_end = tf.zeros((self.batch_size, self.seq_length - half_seq_length), dtype=tf.int32)
        attn_mask = tf.concat([attn_mask_begin, attn_mask_end], axis=1)

        # first forward pass
        output, past_key_values = model(input_ids, attention_mask=attn_mask).to_tuple()

        # create hypothetical next token and extent to next_input_ids
        next_tokens = ids_tensor((self.batch_size, 1), config.vocab_size)

        # change a random masked slice from input_ids
        random_seq_idx_to_change = ids_tensor((1,), half_seq_length).numpy() + 1
        random_other_next_tokens = ids_tensor((self.batch_size, self.seq_length), config.vocab_size)
        vector_condition = tf.range(self.seq_length) == (self.seq_length - random_seq_idx_to_change)
        condition = tf.transpose(
            tf.broadcast_to(tf.expand_dims(vector_condition, -1), (self.seq_length, self.batch_size))
        )
        input_ids = tf.where(condition, random_other_next_tokens, input_ids)

        # append to next input_ids and attn_mask
        next_input_ids = tf.concat([input_ids, next_tokens], axis=-1)
        attn_mask = tf.concat([attn_mask, tf.ones((shape_list(attn_mask)[0], 1), dtype=tf.int32)], axis=1)

        # get two different outputs
        output_from_no_past = model(next_input_ids, attention_mask=attn_mask)["last_hidden_state"]
        output_from_past = model(next_tokens, past_key_values=past_key_values, attention_mask=attn_mask)[
            "last_hidden_state"
        ]

        # select random slice
        random_slice_idx = int(ids_tensor((1,), shape_list(output_from_past)[-1]))
        output_from_no_past_slice = output_from_no_past[:, -1, random_slice_idx]
        output_from_past_slice = output_from_past[:, 0, random_slice_idx]

        # test that outputs are equal for slice
        tf.debugging.assert_near(output_from_past_slice, output_from_no_past_slice, rtol=1e-12)

    def create_and_check_gpt2_model_past_large_inputs(
        self, config, input_ids, input_mask, head_mask, token_type_ids, *args
    ):
        model = TFGPT2Model(config=config)

        input_ids = input_ids[:1, :]
        input_mask = input_mask[:1, :]
        token_type_ids = token_type_ids[:1, :]
        self.batch_size = 1

        # first forward pass
        outputs = model(input_ids, attention_mask=input_mask, token_type_ids=token_type_ids, use_cache=True)

        output, past_key_values = outputs.to_tuple()

        # create hypothetical next token and extent to next_input_ids
        next_tokens = ids_tensor((self.batch_size, 3), config.vocab_size)
        next_attn_mask = ids_tensor((self.batch_size, 3), 2)
        next_token_types = ids_tensor((self.batch_size, 3), self.type_vocab_size)

        # append to next input_ids and token_type_ids
        next_input_ids = tf.concat([input_ids, next_tokens], axis=-1)
        next_attention_mask = tf.concat([input_mask, next_attn_mask], axis=-1)
        next_token_type_ids = tf.concat([token_type_ids, next_token_types], axis=-1)

        output_from_no_past = model(
            next_input_ids, token_type_ids=next_token_type_ids, attention_mask=next_attention_mask
        )["last_hidden_state"]
        output_from_past = model(
            next_tokens,
            token_type_ids=next_token_types,
            attention_mask=next_attention_mask,
            past_key_values=past_key_values,
        )["last_hidden_state"]
        self.parent.assertTrue(output_from_past.shape[1] == next_tokens.shape[1])

        # select random slice
        random_slice_idx = int(ids_tensor((1,), shape_list(output_from_past)[-1]))
        output_from_no_past_slice = output_from_no_past[:, -3:, random_slice_idx]
        output_from_past_slice = output_from_past[:, :, random_slice_idx]

        # test that outputs are equal for slice
        tf.debugging.assert_near(output_from_past_slice, output_from_no_past_slice, rtol=1e-3)

    def create_and_check_gpt2_lm_head(self, config, input_ids, input_mask, head_mask, token_type_ids, *args):
        model = TFGPT2LMHeadModel(config=config)
        inputs = {
            "input_ids": input_ids,
            "attention_mask": input_mask,
            "token_type_ids": token_type_ids,
        }
        result = model(inputs)
        self.parent.assertEqual(result.logits.shape, (self.batch_size, self.seq_length, self.vocab_size))

    def create_and_check_gpt2_double_head(
        self, config, input_ids, input_mask, head_mask, token_type_ids, mc_token_ids, *args
    ):
        model = TFGPT2DoubleHeadsModel(config=config)

        multiple_choice_inputs_ids = tf.tile(tf.expand_dims(input_ids, 1), (1, self.num_choices, 1))
        multiple_choice_input_mask = tf.tile(tf.expand_dims(input_mask, 1), (1, self.num_choices, 1))
        multiple_choice_token_type_ids = tf.tile(tf.expand_dims(token_type_ids, 1), (1, self.num_choices, 1))

        inputs = {
            "input_ids": multiple_choice_inputs_ids,
            "mc_token_ids": mc_token_ids,
            "attention_mask": multiple_choice_input_mask,
            "token_type_ids": multiple_choice_token_type_ids,
        }
        result = model(inputs)
        self.parent.assertEqual(
            result.logits.shape, (self.batch_size, self.num_choices, self.seq_length, self.vocab_size)
        )
        self.parent.assertEqual(result.mc_logits.shape, (self.batch_size, self.num_choices))

    def create_and_check_gpt2_for_sequence_classification(
        self, config, input_ids, input_mask, head_mask, token_type_ids, mc_token_ids, sequence_labels, *args
    ):
        config.num_labels = self.num_labels
        inputs = {
            "input_ids": input_ids,
            "attention_mask": input_mask,
            "token_type_ids": token_type_ids,
            "labels": sequence_labels,
        }
        model = TFGPT2ForSequenceClassification(config)

        result = model(inputs)
        self.parent.assertEqual(result.logits.shape, (self.batch_size, self.num_labels))

    def prepare_config_and_inputs_for_common(self):
        config_and_inputs = self.prepare_config_and_inputs()

        (
            config,
            input_ids,
            input_mask,
            head_mask,
            token_type_ids,
            mc_token_ids,
            sequence_labels,
            token_labels,
            choice_labels,
        ) = config_and_inputs

        inputs_dict = {
            "input_ids": input_ids,
            "token_type_ids": token_type_ids,
            "attention_mask": input_mask,
        }
        return config, inputs_dict


@require_tf
class TFGPT2ModelTest(TFModelTesterMixin, TFCoreModelTesterMixin, PipelineTesterMixin, unittest.TestCase):
    all_model_classes = (
        (TFGPT2Model, TFGPT2LMHeadModel, TFGPT2ForSequenceClassification, TFGPT2DoubleHeadsModel)
        if is_tf_available()
        else ()
    )
    all_generative_model_classes = (TFGPT2LMHeadModel,) if is_tf_available() else ()
    pipeline_model_mapping = (
        {
            "feature-extraction": TFGPT2Model,
            "text-classification": TFGPT2ForSequenceClassification,
            "text-generation": TFGPT2LMHeadModel,
            "zero-shot": TFGPT2ForSequenceClassification,
        }
        if is_tf_available()
        else {}
    )
    test_head_masking = False
    test_onnx = True
    onnx_min_opset = 10

    def setUp(self):
        self.model_tester = TFGPT2ModelTester(self)
        self.config_tester = ConfigTester(self, config_class=GPT2Config, n_embd=37)

    def test_config(self):
        self.config_tester.run_common_tests()

    def test_gpt2_model(self):
        config_and_inputs = self.model_tester.prepare_config_and_inputs()
        self.model_tester.create_and_check_gpt2_model(*config_and_inputs)

    def test_gpt2_model_past(self):
        config_and_inputs = self.model_tester.prepare_config_and_inputs()
        self.model_tester.create_and_check_gpt2_model_past(*config_and_inputs)

    def test_gpt2_model_att_mask_past(self):
        config_and_inputs = self.model_tester.prepare_config_and_inputs()
        self.model_tester.create_and_check_gpt2_model_attention_mask_past(*config_and_inputs)

    def test_gpt2_model_past_large_inputs(self):
        config_and_inputs = self.model_tester.prepare_config_and_inputs()
        self.model_tester.create_and_check_gpt2_model_past_large_inputs(*config_and_inputs)

    def test_gpt2_lm_head(self):
        config_and_inputs = self.model_tester.prepare_config_and_inputs()
        self.model_tester.create_and_check_gpt2_lm_head(*config_and_inputs)

    def test_gpt2_double_head(self):
        config_and_inputs = self.model_tester.prepare_config_and_inputs()
        self.model_tester.create_and_check_gpt2_double_head(*config_and_inputs)

    def test_model_common_attributes(self):
        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()

        for model_class in self.all_model_classes:
            model = model_class(config)
            assert isinstance(model.get_input_embeddings(), tf.keras.layers.Layer)

            if model_class in self.all_generative_model_classes:
                x = model.get_output_embeddings()
                assert isinstance(x, tf.keras.layers.Layer)
                name = model.get_bias()
                assert name is None
            else:
                x = model.get_output_embeddings()
                assert x is None
                name = model.get_bias()
                assert name is None

    def test_gpt2_sequence_classification_model(self):
        config_and_inputs = self.model_tester.prepare_config_and_inputs()
        self.model_tester.create_and_check_gpt2_for_sequence_classification(*config_and_inputs)

    @slow
    def test_model_from_pretrained(self):
        for model_name in TF_GPT2_PRETRAINED_MODEL_ARCHIVE_LIST[:1]:
            model = TFGPT2Model.from_pretrained(model_name)
            self.assertIsNotNone(model)

    # overwrite from common since ONNX runtime optimization doesn't work with tf.gather() when the argument
    # `batch_dims` > 0"
    @require_tf2onnx
    @slow
    def test_onnx_runtime_optimize(self):
        if not self.test_onnx:
            return

        import onnxruntime
        import tf2onnx

        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()

        for model_class in self.all_model_classes:
            # Skip these 2 classes which uses `tf.gather` with `batch_dims=1`
            if model_class in [TFGPT2ForSequenceClassification, TFGPT2DoubleHeadsModel]:
                continue

            model = model_class(config)
            model(model.dummy_inputs)

            onnx_model_proto, _ = tf2onnx.convert.from_keras(model, opset=self.onnx_min_opset)

            onnxruntime.InferenceSession(onnx_model_proto.SerializeToString())

    # TODO (Joao): fix me
    @unittest.skip("Onnx compliancy broke with TF 2.10")
    def test_onnx_compliancy(self):
        pass


@require_tf
class TFGPT2ModelLanguageGenerationTest(unittest.TestCase):
    @slow
    def test_lm_generate_greedy_distilgpt2_batch_special(self):
        model = TFGPT2LMHeadModel.from_pretrained("distilgpt2")
        tokenizer = GPT2Tokenizer.from_pretrained("distilgpt2")

        tokenizer.pad_token = tokenizer.eos_token
        tokenizer.padding_side = "left"

        sentences = ["Today is a beautiful day and", "Yesterday was"]
        input_ids = tokenizer(sentences, return_tensors="tf", padding=True)

        generation_kwargs = {
            "bad_words_ids": [tokenizer("is").input_ids, tokenizer("angry about").input_ids],
            "no_repeat_ngram_size": 2,
            "do_sample": False,
            "repetition_penalty": 1.3,
        }

        output_ids = model.generate(**input_ids, **generation_kwargs)

        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
        expected_output_string = [
            "Today is a beautiful day and I am so happy to be able take part in this amazing event.",
            "Yesterday was a very interesting time for the world to see how much of this is",
        ]
        self.assertListEqual(output_strings, expected_output_string)

    @slow
    def test_lm_generate_sample_distilgpt2_batch_special(self):
        model = TFGPT2LMHeadModel.from_pretrained("distilgpt2")
        tokenizer = GPT2Tokenizer.from_pretrained("distilgpt2")

        tokenizer.pad_token = tokenizer.eos_token
        tokenizer.padding_side = "left"

        sentences = ["Today is a beautiful day and", "Yesterday was"]
        input_ids = tokenizer(sentences, return_tensors="tf", padding=True)

        generation_kwargs = {
            "do_sample": True,
            "bad_words_ids": [tokenizer("is").input_ids, tokenizer("angry about").input_ids],
            "no_repeat_ngram_size": 2,
            "repetition_penalty": 1.3,
            "temperature": 1.5,
            "top_k": 500,
            "top_p": 0.9,
            "seed": [42, 0],  # seed set -> deterministic sampling sequence -> deterministic generation
        }

        # forces the generation to happen on CPU, to avoid GPU-related quirks
        with tf.device(":/CPU:0"):
            output_ids = model.generate(**input_ids, **generation_kwargs)

        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)

        expected_output_string = [
            "Today is a beautiful day and we will make you feel very hot/terrific in all your",
            "Yesterday was known by national television networks as Le Big Show or Wild Dog Jeopard",
        ]
        self.assertListEqual(output_strings, expected_output_string)

    @slow
    def test_lm_generate_greedy_distilgpt2_beam_search_special(self):
        model = TFGPT2LMHeadModel.from_pretrained("distilgpt2")
        tokenizer = GPT2Tokenizer.from_pretrained("distilgpt2")

        tokenizer.pad_token = tokenizer.eos_token
        tokenizer.padding_side = "left"

        sentences = ["Today is a beautiful day and", "Yesterday was"]
        input_ids = tokenizer(sentences, return_tensors="tf", padding=True)

        generation_kwargs = {
            "bad_words_ids": [tokenizer("is").input_ids, tokenizer("angry about").input_ids],
            "no_repeat_ngram_size": 2,
            "do_sample": False,
            "num_beams": 2,
        }

        output_ids = model.generate(**input_ids, **generation_kwargs)

        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
        expected_output_string = [
            "Today is a beautiful day and a great day for all of us.\n\nI’m",
            "Yesterday was the first time that a person has been arrested in the United States for",
        ]
        self.assertListEqual(output_strings, expected_output_string)

    @slow
    def test_lm_generate_distilgpt2_left_padding(self):
        """Tests that the generated text is the same, regarless of left padding"""
        model = TFGPT2LMHeadModel.from_pretrained("distilgpt2")
        tokenizer = GPT2Tokenizer.from_pretrained("distilgpt2")

        tokenizer.pad_token = tokenizer.eos_token
        tokenizer.padding_side = "left"

        generation_kwargs = {
            "bad_words_ids": [tokenizer("is").input_ids, tokenizer("angry about").input_ids],
            "no_repeat_ngram_size": 2,
            "do_sample": False,
            "repetition_penalty": 1.3,
        }
        expected_output_string = (
            "Today is a beautiful day and I am so happy to be able take part in this amazing event."
        )

        sentences = ["Today is a beautiful day and"]
        input_ids = tokenizer(sentences, return_tensors="tf", padding=True)
        # using default length
        output_ids = model.generate(**input_ids, **generation_kwargs)
        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
        self.assertEqual(output_strings[0], expected_output_string)

        sentences = ["Today is a beautiful day and", "This is a very long input that we absolutely don't care about"]
        input_ids = tokenizer(sentences, return_tensors="tf", padding=True)
        # longer max length to capture the full length (remember: it is left padded)
        output_ids = model.generate(**input_ids, **generation_kwargs, max_length=27)
        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
        self.assertEqual(output_strings[0], expected_output_string)

    @slow
    def test_lm_generate_gpt2_greedy_xla(self):
        model = TFGPT2LMHeadModel.from_pretrained("gpt2")
        tokenizer = GPT2Tokenizer.from_pretrained("gpt2")

        tokenizer.pad_token = tokenizer.eos_token
        tokenizer.padding_side = "left"

        sentences = ["The dog", "The flying machine"]
        expected_output_strings = [
            "The dog was found in a field near the intersection of West and West Streets.\n\nThe",
            "The flying machine is a small, lightweight, and lightweight aircraft that can be used for any type of",
        ]
        input_ids = tokenizer(sentences, return_tensors="tf", padding=True)

        output_ids = model.generate(**input_ids, do_sample=False)
        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
        self.assertListEqual(output_strings, expected_output_strings)

        xla_generate = tf.function(model.generate, jit_compile=True)
        output_ids = xla_generate(**input_ids, do_sample=False)
        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
        self.assertListEqual(output_strings, expected_output_strings)

    @slow
    def test_lm_generate_gpt2_sample_xla(self):
        # NOTE: due to the small numerical differences that are natural when we compile to XLA, sampling the same
        # output out of the same seed is far from guaranteed. We can, however, confirm that the results are sensible
        # and that we can seed both versions.

        # forces the generation to happen on CPU, to avoid GPU-related quirks
        with tf.device(":/CPU:0"):
            model = TFGPT2LMHeadModel.from_pretrained("gpt2")
            tokenizer = GPT2Tokenizer.from_pretrained("gpt2")

            tokenizer.pad_token = tokenizer.eos_token
            tokenizer.padding_side = "left"

            sentence = ["The dog", "The flying machine"]
            expected_output_string = [
                "The dog owner asked why did our vet decide there needed to be extra ventilation inside because most"
                " puppies",
                "The flying machine was made by an artist who found it difficult to control it as it did not use",
            ]
            expected_output_string_xla = [
                "The dog has been named in connection with the murder of a 20-year-old man in",
                "The flying machine is a new and improved system to operate and operate a new system and system "
                "system system",
            ]
            input_ids = tokenizer(sentence, return_tensors="tf", padding=True)

            output_ids = model.generate(**input_ids, do_sample=True, seed=[7, 0])
            output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
            self.assertListEqual(output_strings, expected_output_string)

            xla_generate = tf.function(model.generate, jit_compile=True)
            output_ids = xla_generate(**input_ids, do_sample=True, seed=[7, 0])
            output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
            self.assertListEqual(output_strings, expected_output_string_xla)

    @slow
    def test_lm_generate_gpt2_beam_search_xla(self):
        model = TFGPT2LMHeadModel.from_pretrained("gpt2")
        tokenizer = GPT2Tokenizer.from_pretrained("gpt2")

        tokenizer.pad_token = tokenizer.eos_token
        tokenizer.padding_side = "left"

        sentences = ["The dog", "The flying machine"]
        expected_output_strings = [
            "The dog was found in the backyard of a home in the 6500 block of South Main Street",
            "The flying machine is a very powerful machine, but it's not a very powerful machine. It's",
        ]
        input_ids = tokenizer(sentences, return_tensors="tf", padding=True)

        output_ids = model.generate(**input_ids, do_sample=False, num_beams=2)
        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
        self.assertListEqual(output_strings, expected_output_strings)

        xla_generate = tf.function(model.generate, jit_compile=True)
        output_ids = xla_generate(**input_ids, do_sample=False, num_beams=2)
        output_strings = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
        self.assertListEqual(output_strings, expected_output_strings)

    @slow
    def test_contrastive_search_gpt2(self):
        article = (
            "DeepMind Technologies is a British artificial intelligence subsidiary of Alphabet Inc. and research "
            "laboratory founded in 2010. DeepMind was acquired by Google in 2014. The company is based"
        )

        gpt2_tokenizer = GPT2Tokenizer.from_pretrained("gpt2-large")
        gpt2_model = TFGPT2LMHeadModel.from_pretrained("gpt2-large")
        input_ids = gpt2_tokenizer(article, return_tensors="tf")

        outputs = gpt2_model.generate(**input_ids, penalty_alpha=0.6, top_k=4, max_length=256)

        generated_text = gpt2_tokenizer.batch_decode(outputs, skip_special_tokens=True)

        self.assertListEqual(
            generated_text,
            [
                "DeepMind Technologies is a British artificial intelligence subsidiary of Alphabet Inc. and research "
                "laboratory founded in 2010. DeepMind was acquired by Google in 2014. The company is based in London, "
                "United Kingdom\n\nGoogle has a lot of data on its users and uses it to improve its products, such as "
                "Google Now, which helps users find the information they're looking for on the web. But the company "
                "is not the only one to collect data on its users. Facebook, for example, has its own facial "
                "recognition technology, as well as a database of millions of photos that it uses to personalize its "
                "News Feed.\n\nFacebook's use of data is a hot topic in the tech industry, with privacy advocates "
                "concerned about the company's ability to keep users' information private. In a blog post last "
                'year, Facebook CEO Mark Zuckerberg said his company would "do our best to be transparent about our '
                'data use and how we use it."\n\n"We have made it clear that we do not sell or share your data with '
                'third parties," Zuckerberg wrote. "If you have questions or concerns, please reach out to us at '
                'privacy@facebook.com."\n\nGoogle declined to comment on the privacy implications of its use of data, '
                "but said in a statement to The Associated Press that"
            ],
        )

    @slow
    def test_contrastive_search_gpt2_xla(self):
        article = (
            "DeepMind Technologies is a British artificial intelligence subsidiary of Alphabet Inc. and research "
            "laboratory founded in 2010. DeepMind was acquired by Google in 2014. The company is based"
        )

        gpt2_tokenizer = GPT2Tokenizer.from_pretrained("gpt2-large")
        gpt2_model = TFGPT2LMHeadModel.from_pretrained("gpt2-large")
        input_ids = gpt2_tokenizer(article, return_tensors="tf")

        xla_generate = tf.function(gpt2_model.generate, jit_compile=True)
        outputs = xla_generate(**input_ids, penalty_alpha=0.6, top_k=4, max_length=256)

        generated_text = gpt2_tokenizer.batch_decode(outputs, skip_special_tokens=True)

        self.assertListEqual(
            generated_text,
            [
                "DeepMind Technologies is a British artificial intelligence subsidiary of Alphabet Inc. and research "
                "laboratory founded in 2010. DeepMind was acquired by Google in 2014. The company is based in London, "
                "United Kingdom\n\nGoogle has a lot of data on its users and uses it to improve its products, such as "
                "Google Now, which helps users find the information they're looking for on the web. But the company "
                "is not the only one to collect data on its users. Facebook, for example, has its own facial "
                "recognition technology, as well as a database of millions of photos that it uses to personalize its "
                "News Feed.\n\nFacebook's use of data is a hot topic in the tech industry, with privacy advocates "
                "concerned about the company's ability to keep users' information private. In a blog post last "
                'year, Facebook CEO Mark Zuckerberg said his company would "do our best to be transparent about our '
                'data use and how we use it."\n\n"We have made it clear that we do not sell or share your data with '
                'third parties," Zuckerberg wrote. "If you have questions or concerns, please reach out to us at '
                'privacy@facebook.com."\n\nGoogle declined to comment on the privacy implications of its use of data, '
                "but said in a statement to The Associated Press that"
            ],
        )