Reading FSFile fails with TypeError

[gerritholl]

Describe the bug

Trying to pass FSFile objects to satpy.Scene results in a TypeError.

To Reproduce

import satpy
from fsspec.implementations.local import LocalFileSystem

satpy.Scene(filenames=[satpy.readers.FSFile("dummy", fs=LocalFileSystem())])

Expected behavior

I expect satpy to process the files (in this case resulting in FileNotFoundError or a related warning message).

Actual results

Traceback (most recent call last):
  File "/home/gholl/checkouts/protocode/mwe/typeerror-fsfile.py", line 5, in <module>
    satpy.Scene(filenames=[satpy.readers.FSFile(["dummy"], fs=LocalFileSystem())])
  File "/data/gholl/miniconda3/envs/py39/lib/python3.9/site-packages/satpy/scene.py", line 108, in __init__
    self._readers = self._create_reader_instances(filenames=filenames,
  File "/data/gholl/miniconda3/envs/py39/lib/python3.9/site-packages/satpy/scene.py", line 157, in _create_reader_instances
    return load_readers(filenames=filenames,
  File "/data/gholl/miniconda3/envs/py39/lib/python3.9/site-packages/satpy/readers/__init__.py", line 460, in load_readers
    remaining_filenames = set(filenames or [])
TypeError: unhashable type: 'FSFile'

Environment Info:

• Satpy Version: 0.26.0

Additional context

Is this bad enough to make a 0.26.1 release?

[djhoese]

I'm confused at how this doesn't work and isn't tested. Isn't this the intended usage?

[gerritholl]

The bug was introduced in dfeb067 by @gerritholl. I don't know how adding __eq__ makes a type unhashable, and I also don't know how this is not tested. But seeing that I introduced it, I will fix it.