Model strictness / required fields

[tdelmas]

Should model (Java/Rust/...) enforce strictness of required fields?

• If strictness is required, feed with missing fields may be unreadable
• If it is not, it doesn't reflect the specification

Following #202 (comment)

[tdelmas]

Should the behavior be the same for old and new models?

• Pro: consistency
• Con: Old and new models have different goals: Old ones are to consume deprecated fields, new one should drive to a better respect of the specification

A technical solution in rust to satisfy both usage: a new type that can:

1. Explicitly document that the field is required by the specification
2. For the consumption: can be configured to reject/accept/warn for missing fields
3. For the production: can be reject/accept/warn for missing fields

A first simple version could simply respect the first point.

Thoughts @richfab ?

Would that be possible in Go @testower ?

[richfab]

My instinct would be your second point:
Enforce required fields in the language bindings to reflect the spec (in all versions for consistency), and add a configuration for the consumers to reject/accept/warn missing fields.

[testower]

I have no clue about Go, but for the Java model, I don't think the current stack supports it. Jackson supports it, but not the generator library. The only way I think is to check in the generated models and manually add the necessary annotations. Which I'm definitely not in favor of.