Parameter validation in methods and in frontend modules

[bschmalhofer]

Currently OTOBO is pretty basic with parameter checking. All checks are hardcoded. I think that it would be nice to have some declarative parameter checks. For the frontend modules this could also be done with a PreApplication module.

Candidates for parameter checking are:

• Types::Param, as part of Type::Tiny (@bschmalhofer : my favourite), see https://typetiny.toby.ink/NonOO.html
• Params::Validate
• Data::FormValidator
• Params::ValidationCompiler
• JSON::Schema::Modern (@bschmalhofer : another favourite, requires Type::Tiny)
• Specio
• something based on Tests2 pattern

[bschmalhofer]

Marginally related are Perl signatures. They don't do any validation though. See https://www.effectiveperlprogramming.com/2015/04/use-v5-20-subroutine-signatures/ .