fix: service validation in OOB invitation objects

[genaris]

I'm not an expert (neither a fan 😝) of class-validator but I recently found an issue when creating an OutOfBandInvitation instance whose service field contains a plain string. It works and allows to do a toUrl() and so on, but when it passes through the MessageValidator it threw an error saying:

OutOfBandInvitation: Failed to validate class.
    An instance of OutOfBandInvitation has failed the validation:
     - property services[0] has failed the following constraints: each value in nested property services must be either object or array·

I found that services field has both @IsStringOrInstance and @ValidateNested decorators. The first one seems to be doing the correct check on every element of the array, while the latter (which is the one throwing the error) seems to me redundant in this case. If I remove it, class validation passes (as expected).

So here I'm removing @ValidateNested decorator. Not sure if it's the best approach, but of course happy to change it if there is a more appropriate way.

[genaris]

Another interesting thing I found related to class-validator is that @IsUrl decorator (without any parameters) requires the top-level domain (TLD) to consider an URL as valid. So for instance if I set imageUrl to http://localhost/image.jpg it will fail.

I guess this won't represent any issue in production environments, but could be inconvenient when doing local development or accessing resources in a local area network.

[codecov-commenter]

Codecov Report

Merging #1575 (982b189) into main (d2f8851) will decrease coverage by 0.01%.
Report is 1 commits behind head on main.
The diff coverage is 80.00%.

@@            Coverage Diff             @@
##             main    #1575      +/-   ##
==========================================
- Coverage   85.73%   85.73%   -0.01%     
==========================================
  Files         950      950              
  Lines       22753    22756       +3     
  Branches     3981     3981              
==========================================
+ Hits        19508    19510       +2     
- Misses       3060     3061       +1     
  Partials      185      185              

Files Changed	Coverage Δ
...re/src/modules/oob/messages/OutOfBandInvitation.ts	95.06% <ø> (ø)
...d/src/anoncreds/services/CheqdAnonCredsRegistry.ts	79.54% <80.00%> (-0.46%)	⬇️

[TimoGlastra]

I guess this won't represent any issue in production environments, but could be inconvenient when doing local development or accessing resources in a local area network.

Hmm yeah that's a bit weird. But not seeing any immediate issues with it.