AIBL-to-BIDS converter is not warning the user when not converting some sessions

[AliceJoubert]

In AIBL-to-BIDS, there are two ways an image can be missing from the output :

• It can happen that the converter chooses not to convert some images. Sometimes, images actually exist, are under the expected format ie inside a folder named after the date of the examination but the session cannot be matched to the metadata because the examination date is not indicated in it.

For example :

In this case, both sessions won't be converted even though the data exists since the value for EXAMDATE is missing.

The user is not warned about it at all, which can be confusing.

• Conversion can fail. The following function is supposed to be warning users but it is not tested:
  

  clinica/clinica/converters/aibl_to_bids/_converter.py

  Lines 129 to 141 in 4f907bc

  	def _warn_about_missing_files(files: list[list[Optional[Path]]]):
  	from clinica.utils.stream import cprint
  	missing_files = []
  	for files_for_given_modality in files:
  	for file in files_for_given_modality:
  	if file is not None and not file.exists():
  	missing_files.append(file)
  	if missing_files:
  	msg = "The following file were not converted:\n" + "\n".join(
  	(str(f) for f in missing_files)
  	)
  	cprint(msg=msg, lvl="warning")

For example, if the conversion fails earlier and there is no filename for a failure then the user is not warned.

[NicolasGensollen]

Thanks for looking into this @AliceJoubert !
Are you planning to work on it when you have some time, or should we ask @Adam-Ismaili-92 to take a look ?

[AliceJoubert]

I personally did not plan to resolve it soon at it is not so urgent, and this PR touches parts of the converter that are not tested a lot. We would probably need to add tests before trying to change what is done. Maybe I can open intermediary issues for tests if @Adam-Ismaili-92 wants to work on that