New fints2ledger can't deal with empty payees

[varac]

I have a lot of theses matching rules where I want to match a transaction where the payee must empty:

  - fills:
    - match:
        payee: ""
        posting: "Basislastschrift"
        purpose: "Spotify.*"
      fill:
        credit_account: "Expenses:Music"

Latest fints2ledger fails with:

fints2ledger: makeRegexOpts failed
CallStack (from HasCallStack):
  error, called at src/Text/Regex/Base/RegexLike.hs:137:32 in regex-base-0.94.0.2-69b4ec641c8aff5fa1d43081c9aac99741c6c4858c40d670520e7e1e05fde420:Text.Regex.Base.RegexLike

When I remove the payee: "" line it works. Old fints2ledger handled this case fine.

[MoritzR]

Are you sure the old version handled it correctly? Using "" as an regex would match any text, as far as I can see it:

>>> "Matched" if re.match("","") else "No Match"
'Matched'
>>> "Matched" if re.match("","not empty") else "No Match"
'Matched'
>>> "Matched" if re.match("^$","") else "No Match"
'Matched'
>>> "Matched" if re.match("^$","not empty") else "No Match"
'No Match'

If you want to match the empty string, use ^$ instead.

I have to say that I find using "" as a match much more intuitive, though. Maybe requiring regexes there was not the best decision, but that is kind of hard to change now.

I will do something about the error message though.

[varac]

Oh you're right, apparently it never matched but I didn't realize it :facepalm: Using "^$" works ! No, I really like that regex can be used, it makes fints2ledger much more flexbile.