[test] add a `IPAdapterTexterMixin`

[yiyixuxu]

I think we should add a IPAdapterTexterMIxin and run fast tests on every pipeline that supports IP-Adapter, so that we will be able to catch breaking changes like this #6828

some thoughts:

• we can add a IPAdapterTexterMIxin class to test_pipelines_common.py https://github.com/huggingface/diffusers/blob/9cc59ba0891c3ccbebfcbb6784f4dde2d5bd8556/tests/pipelines/test_pipelines_common.py#L62C7-L62C32
• we can then add IPAdapterTexterMIxin as a base class to the fast tests of all the pipelines support ip-adapter, for example,add here for StableDiffusionXLPipelineFastTests (

  diffusers/tests/pipelines/stable_diffusion_xl/test_stable_diffusion_xl.py

  Line 59 in 9cc59ba

  PipelineLatentTesterMixin, PipelineTesterMixin, SDXLOptionalComponentsTesterMixin, unittest.TestCase

  )
• we can either make a dummy repo for ip-adapter ( i.e.hf-internal-testing/tiny_random_ip_adapter) or use this method https://github.com/huggingface/diffusers/blob/9cc59ba0891c3ccbebfcbb6784f4dde2d5bd8556/tests/models/unets/test_models_unet_2d_condition.py#L59C34-L59C39 to create dummy_ip_adapter_state_dict based on self.get_dummy_components()['unet']
• add a simple test:
  • the output of the pipeline without ip-adapter should be the same as pipeline with ip-adapter but with ip_adapter_scale = 0
  • the output of pipeline without ip-adapter should NOT be same as pipeline with ip-adapter with ip_adapter_scale = 1
• the tests should only run if the pipeline's __call__ method has the ip_adapter_image argument

cc @DN6 @sayakpaul let me know what you guys think!

[sayakpaul]

100 percent agree.

[DN6]

Sounds good to me 👍🏽

[UmerHA]

Hey @yiyixuxu! I'd give this a go, if okay for you!

[yiyixuxu]

@UmerHA
we already have a PR open and very close to merge for this now:) #6862

checkout other issues here to see if any of them interest you:)
https://github.com/huggingface/diffusers/issues?q=is%3Aopen+is%3Aissue+label%3Acontributions-welcome