Fix failing enum mapping for backed PHP enums

[ioigoume]

JsonMapper failed to map JSON scalar values into PHP 8.1+ backed enum-typed properties and incorrectly treated them as objects. This caused errors like:

JsonMapper_Exception: JSON property "exampleEnumMode" must be an object, string given.

What changed

• Added an enum handling condition branch that:
  • Detects enum-typed targets via enum_exists($type).
  • Converts the incoming JSON scalar using type::tryFrom(jvalue).
  • Throws a JsonMapper_Exception with a clear message if the value is not part of the enum.
  • Sets the property with the resulting enum case.

Before

• Mapping a JSON string (e.g., "optional") into an enum-typed property resulted in an error insisting on an object type.

After

• Mapping a JSON string that matches a backed enum value (e.g., "optional") correctly produces the corresponding enum case (e.g., ExampleEnumMode::OPTIONAL).
• Invalid values now yield a precise error: Enum value "" does not belong to enumerator class.

[cweiske]

This looks like AI generated code. I don't accept code generated by an AI.

[ioigoume]

This looks like AI generated code. I don't accept code generated by an AI.

@cweiske

What part of the actual code is AI generated? I am getting this issue:

JsonMapper_Exception: JSON property "encryptAssertionsMode" must be an object, string given

and i tracked down the problem to the JsonMapper.php::299. I fixed and tested that i do not get the error report in my testing environment. Then i added a couple of tests that support this. Then i opened the PR. Simple as that.

[cweiske]

The issue description looks totally generated.

[ioigoume]

The issue description looks totally generated.

@cweiske yes it is. This does not make the code neither AI generated, nor untested/unverified.
I came across an issue, while using the library. I came up with a solution and i proposed that solution. This entails that i had to run and extend the tests, run the code sniffer and fix any issues, etc. At the end i used the convenience of an AI generator to create a better description/comment of what i found. Is that a bad thing?

[ioigoume]

Related Issue #247

[SvenRtbg]

Related Issue #247

Please follow up on this issue's discussion and illustrate how you'd go forward when a setting is stating that no objects are being generated when scalar values are encountered. Also consider the mentioned issue with DateTime*.

[dktapps]

This will crash if $type refers to a UnitEnum, which doesn't have tryFrom()

[dktapps]

Feels weird putting this code here too since the rest of these branches concern arrays and iterables