fix: remove extra parameter in accelerator registry decorator

[YgLK]

What does this PR do?

Fixes #20973

---

📚 Documentation preview 📚: https://pytorch-lightning--20975.org.readthedocs.build/en/20975/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87%. Comparing base (c6b6553) to head (b6242d9).

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #20975   +/-   ##
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  Coverage      87%      87%           
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  Files         268      268           
  Lines       23460    23460           
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  Hits        20399    20399           
  Misses       3061     3061           

[Borda]

lets pls add a test to reproduce your reported casem and demonstrate that this change fixes it 🦩

[YgLK]

The tests have been updated. I’d be glad if you could take a look at them

[SkafteNicki]

@Borda @YgLK here are a new version of https://github.com/Lightning-AI/pytorch-lightning/blob/master/tests/tests_fabric/accelerators/test_registry.py that includes relevant testing. In particular the test_registry_as_decorator fails on master but passes on this PR:

# Copyright The Lightning AI team.
#
# 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 typing import Any

import pytest
import torch

from lightning.fabric.accelerators import ACCELERATOR_REGISTRY, Accelerator
from lightning.fabric.accelerators.registry import _AcceleratorRegistry
from lightning.fabric.utilities.exceptions import MisconfigurationException


class TestAccelerator(Accelerator):
    """Helper accelerator class for testing."""
    
    def __init__(self, param1=None, param2=None):
        self.param1 = param1
        self.param2 = param2
        super().__init__()

    def setup_device(self, device: torch.device) -> None:
        pass

    def teardown(self) -> None:
        pass

    @staticmethod
    def parse_devices(devices):
        return devices

    @staticmethod
    def get_parallel_devices(devices):
        return ["foo"] * devices

    @staticmethod
    def auto_device_count():
        return 3

    @staticmethod
    def is_available():
        return True


def test_accelerator_registry_with_new_accelerator():
    accelerator_name = "custom_accelerator"
    accelerator_description = "Custom Accelerator"

    class CustomAccelerator(Accelerator):
        def __init__(self, param1, param2):
            self.param1 = param1
            self.param2 = param2
            super().__init__()

        def setup_device(self, device: torch.device) -> None:
            pass

        def get_device_stats(self, device: torch.device) -> dict[str, Any]:
            pass

        def teardown(self) -> None:
            pass

        @staticmethod
        def parse_devices(devices):
            return devices

        @staticmethod
        def get_parallel_devices(devices):
            return ["foo"] * devices

        @staticmethod
        def auto_device_count():
            return 3

        @staticmethod
        def is_available():
            return True

    ACCELERATOR_REGISTRY.register(
        accelerator_name, CustomAccelerator, description=accelerator_description, param1="abc", param2=123
    )

    assert accelerator_name in ACCELERATOR_REGISTRY

    assert ACCELERATOR_REGISTRY[accelerator_name]["description"] == accelerator_description
    assert ACCELERATOR_REGISTRY[accelerator_name]["init_params"] == {"param1": "abc", "param2": 123}
    assert ACCELERATOR_REGISTRY[accelerator_name]["accelerator_name"] == accelerator_name

    assert isinstance(ACCELERATOR_REGISTRY.get(accelerator_name), CustomAccelerator)

    ACCELERATOR_REGISTRY.remove(accelerator_name)
    assert accelerator_name not in ACCELERATOR_REGISTRY


def test_available_accelerators_in_registry():
    assert ACCELERATOR_REGISTRY.available_accelerators() == {"cpu", "cuda", "mps", "tpu"}


def test_registry_as_decorator():
    """Test that the registry can be used as a decorator."""
    test_registry = _AcceleratorRegistry()
    
    # Test decorator usage
    @test_registry.register("test_decorator", description="Test decorator accelerator", param1="value1", param2=42)
    class DecoratorAccelerator(TestAccelerator):
        pass
    
    # Verify registration worked
    assert "test_decorator" in test_registry
    assert test_registry["test_decorator"]["description"] == "Test decorator accelerator"
    assert test_registry["test_decorator"]["init_params"] == {"param1": "value1", "param2": 42}
    assert test_registry["test_decorator"]["accelerator"] == DecoratorAccelerator
    assert test_registry["test_decorator"]["accelerator_name"] == "test_decorator"
    
    # Test that we can instantiate the accelerator
    instance = test_registry.get("test_decorator")
    assert isinstance(instance, DecoratorAccelerator)
    assert instance.param1 == "value1"
    assert instance.param2 == 42


def test_registry_as_static_method():
    """Test that the registry can be used as a static method call."""
    test_registry = _AcceleratorRegistry()
    
    class StaticMethodAccelerator(TestAccelerator):
        pass
    
    # Test static method usage
    result = test_registry.register(
        "test_static", 
        StaticMethodAccelerator, 
        description="Test static method accelerator", 
        param1="static_value", 
        param2=100
    )
    
    # Verify registration worked
    assert "test_static" in test_registry
    assert test_registry["test_static"]["description"] == "Test static method accelerator"
    assert test_registry["test_static"]["init_params"] == {"param1": "static_value", "param2": 100}
    assert test_registry["test_static"]["accelerator"] == StaticMethodAccelerator
    assert test_registry["test_static"]["accelerator_name"] == "test_static"
    assert result == StaticMethodAccelerator  # Should return the accelerator class
    
    # Test that we can instantiate the accelerator
    instance = test_registry.get("test_static")
    assert isinstance(instance, StaticMethodAccelerator)
    assert instance.param1 == "static_value"
    assert instance.param2 == 100


def test_registry_without_parameters():
    """Test registration without init parameters."""
    test_registry = _AcceleratorRegistry()
    
    class SimpleAccelerator(TestAccelerator):
        def __init__(self):
            super().__init__()
    
    test_registry.register("simple", SimpleAccelerator, description="Simple accelerator")
    
    assert "simple" in test_registry
    assert test_registry["simple"]["description"] == "Simple accelerator"
    assert test_registry["simple"]["init_params"] == {}
    
    instance = test_registry.get("simple")
    assert isinstance(instance, SimpleAccelerator)

[YgLK]

@SkafteNicki thanks for help - it looks great. I updated the tests 79c5c42