Review exceptions in BagProfile about bagit-support HOT 1 CLOSED

Note that I'm trying to inform these from the ideas on the Condition Failures Explained page from guava.

For BagProfile I think it makes sense to use a checked exception - we already have ProfileValidationException so that's a good place to start, though it is a checked exception. I would probably prefer to use a Result and have that provide information on errors over throwing an exception, but trying to keep this to as few changes as possible at the moment.

There are also other classes throwing unchecked exceptions:

BagConfig

• when creating, a RuntimeException is thrown if there is no Bag-Info section
  • Is this really an error? I can see why it might be enforced before, but this might be able to be removed
• when creating, a RuntimeException is thrown if the path to the yaml does not exist
  • The constructor could be updated to take a stream -- still likely exceptions that can occur (or Reader looks like it would be the best fit)
• when creating, a RuntimeException is thrown if the yaml cannot be parsed
  • IllegalStateException?

SerializationSupport

• when getting a BagDeserializer, a RuntimeException is thrown if tika cannot detect the content type
  • Maybe allow the IOException to continue up the chain
• when getting a BagDeserializer, a RuntimeException is thrown if the BagProfile does not support the content type
  • Initially was thinking about using an IllegalArgumentException, but it's the file being read so maybe there's a better option
• when getting a BagSerializer, a RuntimeException is thrown if the BagProfile does not support the content type
  • same as above

BagWriter

• when registering a checksum, a RuntimeException is thrown if the MessageDigest algorithm was not registered when creating the BagWriter
  • Maybe IllegalArgumentException would be better, since the argument for the algorithm is invalid

from bagit-support.