Files
trl/tests/test_reward_trainer.py
Quentin Gallouédec da209f89fc 🎁 RewardTrainer refactor (#4093)
Co-authored-by: juejuezi <juejuezi.git@foxmail.com>
Co-authored-by: Yi Shi <96773624+singing-cat@users.noreply.github.com>
Co-authored-by: Kashif Rasul <kashif.rasul@gmail.com>
2025-09-30 15:13:45 -06:00

835 lines
37 KiB
Python

# Copyright 2020-2025 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.
import pathlib
import unittest
import torch
from datasets import load_dataset
from parameterized import parameterized
from transformers import AutoModelForSequenceClassification, AutoTokenizer
from transformers.testing_utils import require_peft
from transformers.utils import is_peft_available
from trl import RewardConfig, RewardTrainer
from trl.trainer.reward_trainer import DataCollatorForPreference
from .testing_utils import TrlTestCase
if is_peft_available():
from peft import LoraConfig, PeftModel, get_peft_model
class TestDataCollatorForPreference(TrlTestCase):
def test_basic_padding(self):
"""Test basic padding functionality without completion masks."""
self.collator = DataCollatorForPreference(pad_token_id=0)
examples = [
{"chosen_input_ids": [1, 2, 3], "rejected_input_ids": [4, 5]},
{"chosen_input_ids": [6, 7], "rejected_input_ids": [8]},
]
result = self.collator(examples)
torch.testing.assert_close(result["input_ids"], torch.tensor([[1, 2, 3], [6, 7, 0], [4, 5, 0], [8, 0, 0]]))
torch.testing.assert_close(
result["attention_mask"], torch.tensor([[1, 1, 1], [1, 1, 0], [1, 1, 0], [1, 0, 0]])
)
def test_pad_to_multiple_of(self):
"""Test padding to multiple of specified value."""
collator = DataCollatorForPreference(pad_token_id=0, pad_to_multiple_of=4)
examples = [
{"chosen_input_ids": [1, 2, 3], "rejected_input_ids": [4, 5]},
{"chosen_input_ids": [6, 7], "rejected_input_ids": [8]},
]
result = collator(examples)
torch.testing.assert_close(
result["input_ids"], torch.tensor([[1, 2, 3, 0], [6, 7, 0, 0], [4, 5, 0, 0], [8, 0, 0, 0]])
)
torch.testing.assert_close(
result["attention_mask"], torch.tensor([[1, 1, 1, 0], [1, 1, 0, 0], [1, 1, 0, 0], [1, 0, 0, 0]])
)
def test_single_example(self):
"""Test collator with a single example."""
self.collator = DataCollatorForPreference(pad_token_id=0)
examples = [{"chosen_input_ids": [1, 2, 3], "rejected_input_ids": [4, 5]}]
result = self.collator(examples)
torch.testing.assert_close(result["input_ids"], torch.tensor([[1, 2, 3], [4, 5, 0]]))
torch.testing.assert_close(result["attention_mask"], torch.tensor([[1, 1, 1], [1, 1, 0]]))
def test_different_pad_token_id(self):
"""Test with different pad token ID."""
collator = DataCollatorForPreference(pad_token_id=999)
examples = [
{"chosen_input_ids": [1, 2, 3], "rejected_input_ids": [4, 5]},
{"chosen_input_ids": [6, 7], "rejected_input_ids": [8]},
]
result = collator(examples)
torch.testing.assert_close(
result["input_ids"], torch.tensor([[1, 2, 3], [6, 7, 999], [4, 5, 999], [8, 999, 999]])
)
torch.testing.assert_close(
result["attention_mask"], torch.tensor([[1, 1, 1], [1, 1, 0], [1, 1, 0], [1, 0, 0]])
)
def test_collate_with_margin(self):
self.collator = DataCollatorForPreference(pad_token_id=0)
examples = [
{"chosen_input_ids": [1, 2, 3], "rejected_input_ids": [4, 5], "margin": 0.1},
{"chosen_input_ids": [6, 7], "rejected_input_ids": [8], "margin": 0.2},
]
result = self.collator(examples)
torch.testing.assert_close(result["input_ids"], torch.tensor([[1, 2, 3], [6, 7, 0], [4, 5, 0], [8, 0, 0]]))
torch.testing.assert_close(
result["attention_mask"], torch.tensor([[1, 1, 1], [1, 1, 0], [1, 1, 0], [1, 0, 0]])
)
torch.testing.assert_close(result["margin"], torch.tensor([0.1, 0.2]))
class RewardTrainerTester(TrlTestCase):
@parameterized.expand(
[
("trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",),
("trl-internal-testing/tiny-Qwen3MoeForSequenceClassification",),
("trl-internal-testing/tiny-LlamaForSequenceClassification-3.2",),
]
)
def test_train(self, model_id):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(model=model_id, args=training_args, train_dataset=dataset)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
@parameterized.expand(
[
("standard_preference",),
("conversational_preference",),
("standard_implicit_prompt_preference",),
("conversational_implicit_prompt_preference",),
]
)
def test_train_dataset_types(self, config_name):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", config_name, split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_model(self):
# Instantiate the model
model = AutoModelForSequenceClassification.from_pretrained(
"trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5"
)
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(model=model, args=training_args, train_dataset=dataset)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_from_causal_lm(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen3ForCausalLM", args=training_args, train_dataset=dataset
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_model_dtype(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(
output_dir=self.tmp_dir,
model_init_kwargs={"dtype": torch.float16},
learning_rate=0.1,
report_to="none",
)
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
# For some reasonn model.layers.0.input_layernorm.weight doesn't change in GitHub Actions but does
# locally. We ignore this parameter for now
if "layernorm" in n:
continue
new_param = trainer.model.get_parameter(n)
# Check the torch dtype
self.assertEqual(new_param.dtype, torch.float16)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
@require_peft
def test_train_dense_with_peft_config(self):
# Get the base model parameter names
model_id = "trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5"
model = AutoModelForSequenceClassification.from_pretrained(model_id)
base_param_names = [f"base_model.model.{n}" for n, _ in model.named_parameters()]
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(
model=model_id,
args=training_args,
train_dataset=dataset,
peft_config=LoraConfig(),
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the peft params have changed and the base model params have not changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
if n in base_param_names: # We expect the base model parameters to be the same
self.assertTrue(torch.allclose(param, new_param), f"Parameter {n} has changed")
elif "base_layer" not in n: # We expect the peft parameters to be different (except for the base layer)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
@require_peft
def test_train_moe_with_peft_config(self):
# Get the base model parameter names
model_id = "trl-internal-testing/tiny-Qwen3MoeForSequenceClassification"
model = AutoModelForSequenceClassification.from_pretrained(model_id)
base_param_names = [f"base_model.model.{n}" for n, _ in model.named_parameters()]
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(
model=model_id,
args=training_args,
train_dataset=dataset,
peft_config=LoraConfig(target_modules=["up_proj", "down_proj", "score"]),
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the peft params have changed and the base model params have not changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
if n in base_param_names: # We expect the base model parameters to be the same
self.assertTrue(torch.allclose(param, new_param), f"Parameter {n} has changed")
elif "base_layer" not in n: # We expect the peft parameters to be different (except for the base layer)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
@require_peft
def test_train_peft_model(self):
# Get the base model
model_id = "trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5"
model = AutoModelForSequenceClassification.from_pretrained(model_id)
# Get the base model parameter names
base_param_names = [f"base_model.model.{n}" for n, _ in model.named_parameters()]
# Turn the model into a peft model
lora_config = LoraConfig()
model = get_peft_model(model, lora_config)
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(model=model, args=training_args, train_dataset=dataset)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the peft params have changed and the base model params have not changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
if n in base_param_names: # We expect the base model parameters to be the same
self.assertTrue(torch.allclose(param, new_param), f"Parameter {n} has changed")
elif "base_layer" not in n: # We expect the peft parameters to be different (except for the base layer)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
@require_peft
def test_train_dense_with_peft_config_and_gradient_checkpointing(self):
# Get the base model parameter names
model_id = "trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5"
model = AutoModelForSequenceClassification.from_pretrained(model_id)
base_param_names = [f"base_model.model.{n}" for n, _ in model.named_parameters()]
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, gradient_checkpointing=True, report_to="none")
trainer = RewardTrainer(
model=model_id,
args=training_args,
train_dataset=dataset,
peft_config=LoraConfig(),
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the peft params have changed and the base model params have not changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
if n in base_param_names: # We expect the base model parameters to be the same
self.assertTrue(torch.allclose(param, new_param), f"Parameter {n} has changed")
elif "base_layer" not in n: # We expect the peft parameters to be different (except for the base layer)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
@require_peft
def test_train_moe_with_peft_config_and_gradient_checkpointing(self):
# Get the base model parameter names
model_id = "trl-internal-testing/tiny-Qwen3MoeForSequenceClassification"
model = AutoModelForSequenceClassification.from_pretrained(model_id)
base_param_names = [f"base_model.model.{n}" for n, _ in model.named_parameters()]
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, gradient_checkpointing=True, report_to="none")
trainer = RewardTrainer(
model=model_id,
args=training_args,
train_dataset=dataset,
peft_config=LoraConfig(target_modules=["up_proj", "down_proj", "score"]),
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the peft params have changed and the base model params have not changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
if n in base_param_names: # We expect the base model parameters to be the same
self.assertTrue(torch.allclose(param, new_param), f"Parameter {n} has changed")
elif "base_layer" not in n: # We expect the peft parameters to be different (except for the base layer)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
@require_peft
def test_train_with_peft_model_and_gradient_checkpointing(self):
# Get the base model parameter names
model_id = "trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5"
model = AutoModelForSequenceClassification.from_pretrained(model_id)
base_param_names = [f"base_model.model.{n}" for n, _ in model.named_parameters()]
model = get_peft_model(model, LoraConfig())
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, gradient_checkpointing=True, report_to="none")
trainer = RewardTrainer(model=model, args=training_args, train_dataset=dataset)
# Verify model is a PeftModel
self.assertIsInstance(trainer.model, PeftModel)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the peft params have changed and the base model params have not changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
if n in base_param_names: # We expect the base model parameters to be the same
self.assertTrue(torch.allclose(param, new_param), f"Parameter {n} has changed")
elif "base_layer" not in n: # We expect the peft parameters to be different (except for the base layer)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_with_pretokenized_data(self):
# Get the dataset
model_id = "trl-internal-testing/tiny-Qwen2ForCausalLM-2.5"
tokenizer = AutoTokenizer.from_pretrained(model_id)
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
def tokenize_example(example):
return {
"chosen_input_ids": tokenizer(example["chosen"]).input_ids,
"rejected_input_ids": tokenizer(example["rejected"]).input_ids,
}
# Apply tokenization
tokenized_dataset = dataset.map(tokenize_example, remove_columns=["chosen", "rejected"])
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(model=model_id, args=training_args, train_dataset=tokenized_dataset)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_with_iterable_dataset(self):
# Get the dataset
dataset = load_dataset(
"trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train", streaming=True
)
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, max_steps=3, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_with_chat_template_kwargs(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
tokenizer = AutoTokenizer.from_pretrained("trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5")
# The following template is a simplified version of the Qwen chat template, where an additional argument
# `role_capital` is used to control the capitalization of roles.
tokenizer.chat_template = '{%- if messages[0]["role"] == "system" -%} {{ "<|im_start|>" + ("SYSTEM" if role_capital else "system") + "\\n" + messages[0]["content"] + "<|im_end|>\\n" }}{%- else -%} {{ "<|im_start|>" + ("SYSTEM" if role_capital else "system") + "\\nYou are Qwen, created by Alibaba Cloud. You are a helpful assistant.<|im_end|>\\n" }}{%- endif -%}{%- for message in messages -%} {%- if (message.role == "user") or (message.role == "system" and not loop.first) or (message.role == "assistant" and not message.tool_calls) -%} {{ "<|im_start|>" + (message.role.upper() if role_capital else message.role) + "\\n" + message.content + "<|im_end|>\\n" }} {%- elif message.role == "assistant" -%} {{ "<|im_start|>" + ("ASSISTANT" if role_capital else "assistant") }} {%- if message.content -%} {{ "\\n" + message.content }} {%- endif -%} {{ "<|im_end|>\\n" }} {%- elif message.role == "tool" -%} {%- if (loop.index0 == 0) or (messages[loop.index0 - 1].role != "tool") -%} {{ "<|im_start|>" + ("USER" if role_capital else "user") }} {%- endif -%} {{ "\\n<tool_response>\\n" + message.content + "\\n</tool_response>" }} {%- if loop.last or (messages[loop.index0 + 1].role != "tool") -%} {{ "<|im_end|>\\n" }} {%- endif -%} {%- endif -%}{%- endfor -%}{%- if add_generation_prompt -%} {{ "<|im_start|>" + ("ASSISTANT" if role_capital else "assistant") + "\\n" }}{%- endif -%}'
dataset.add_column("chat_template_kwargs", [{"role_capital": bool(i % 2)} for i in range(len(dataset))])
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_with_set_chat_template_from_model(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "conversational_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, chat_template_path="Qwen/Qwen3-4B", report_to="none")
# trl-internal-testing/tiny-GPTNeoXForSequenceClassification doesn't have a chat template set by default
trainer = RewardTrainer(
model="trl-internal-testing/tiny-GPTNeoXForSequenceClassification",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
# RewardTrainer uses a mean-free loss that cancels uniform shifts in output scores. Since GPT-NeoX models
# include a final LayerNorm, its bias consistently receives zero gradient and remains unchanged, so we skip
# this parameter.
if n == "gpt_neox.final_layer_norm.bias":
continue
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_with_set_chat_template_from_path(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "conversational_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(
output_dir=self.tmp_dir,
chat_template_path=str(pathlib.Path(__file__).parent / "data" / "template.jinja"),
report_to="none",
)
# trl-internal-testing/tiny-GPTNeoXForSequenceClassification doesn't have a chat template set by default
trainer = RewardTrainer(
model="trl-internal-testing/tiny-GPTNeoXForSequenceClassification",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
# RewardTrainer uses a mean-free loss that cancels uniform shifts in output scores. Since GPT-NeoX models
# include a final LayerNorm, its bias consistently receives zero gradient and remains unchanged, so we skip
# this parameter.
if n == "gpt_neox.final_layer_norm.bias":
continue
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
# Check that the template saved in the output directory is the same as the one used for training
template_path = pathlib.Path(self.tmp_dir) / "checkpoint-9" / "chat_template.jinja"
self.assertTrue(template_path.exists(), f"Chat template not found at {template_path}")
with open(template_path) as f:
template_content = f.read()
with open(training_args.chat_template_path) as f:
original_template_content = f.read()
self.assertEqual(
template_content, original_template_content, "Chat template content does not match the original"
)
@unittest.skip("Skipping until we have a dataset with tool calls")
def test_train_toolcall_data(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/toolcall", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_with_eval(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, eval_strategy="steps", eval_steps=3, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset["train"],
eval_dataset=dataset["test"],
)
# Train the model
trainer.train()
# Check that the eval loss is not None
self.assertIsNotNone(trainer.state.log_history[0]["eval_loss"])
def test_train_with_multiple_eval_dataset(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, eval_strategy="steps", eval_steps=3, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset["train"],
eval_dataset={"data1": dataset["test"], "data2": dataset["test"]},
)
# Train the model
trainer.train()
# Check that the eval losses are not None
self.assertIsNotNone(trainer.state.log_history[-3]["eval_data1_loss"])
self.assertIsNotNone(trainer.state.log_history[-2]["eval_data2_loss"])
def test_train_with_gradient_checkpointing(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, gradient_checkpointing=True, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_tag_added(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
train_dataset=dataset,
)
for tag in ["reward-trainer", "trl"]:
self.assertIn(tag, trainer.model.model_tags)
@require_peft
def test_tag_added_peft(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
train_dataset=dataset,
peft_config=LoraConfig(),
)
for tag in ["reward-trainer", "trl"]:
self.assertIn(tag, trainer.model.model_tags)
def test_train_with_margin(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
def add_margin(example):
# dummy margin based on the length of the chosen summary
return {"margin": len(example["chosen"])}
dataset = dataset.map(add_margin)
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")
def test_train_with_center_rewards_coefficient(self):
# Get the dataset
dataset = load_dataset("trl-internal-testing/zen", "standard_implicit_prompt_preference", split="train")
# Initialize the trainer
training_args = RewardConfig(output_dir=self.tmp_dir, center_rewards_coefficient=0.01, report_to="none")
trainer = RewardTrainer(
model="trl-internal-testing/tiny-Qwen2ForSequenceClassification-2.5",
args=training_args,
train_dataset=dataset,
)
# Save the initial parameters to compare them later
previous_trainable_params = {n: param.clone() for n, param in trainer.model.named_parameters()}
# Train the model
trainer.train()
# Check that the training loss is not None
self.assertIsNotNone(trainer.state.log_history[-1]["train_loss"])
# Check the params have changed
for n, param in previous_trainable_params.items():
new_param = trainer.model.get_parameter(n)
self.assertFalse(torch.allclose(param, new_param), f"Parameter {n} has not changed")