Support Composed Constraints

[michael-arndt-gcx]

Jakarta Bean Validation allows to compose constraints as described in 3.3. Constraint composition.

I'd like to implement basic support for this. My idea would be to add a preprocessing step to

swagger-core/modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/ModelResolver.java

Line 1560 in df88c8a

protected void applyBeanValidatorAnnotations(BeanPropertyDefinition propDef, Schema property, Annotation[] annotations, Schema parent, boolean applyNotNullAnnotations) {

which flattens all Annotations. That means: when an annotation is annotated with javax.validation.Constraint, all its annotations are treated as if all annotations are on the annotated element.

This has been requested as feature e.g. in springdoc/springdoc-openapi#1486

[wudip]

Hi @michael-arndt-gcx, I tried to extend your idea into a PR since this issue bugs me for some time: #4801 It works for me locally.

[michael-arndt-gcx]

Hey, really nice to see someone pick this up! I've also started, but then it came clear I'll loose my day-job, so other things take priority 😅

One problem with mapping bean validation to OpenAPI is that Bean Validation allows an arbitrary number of constraints, even of the same type, whereas OpenAPI allows only up to one. So for example you could add 100 different minimum value constraints. In Bean Validation, they would all be evaluated, and every violated constraint would be reported.
(This also makes workaround like copying the same validations from the compound to the field – what we did for semantic reasons – a bit wonky)

That makes the adoption a bit less trivial, if @Min(5) and @Min(3) is there, then 3 should take precedence.

For Pattern it's worse. In theory we could create the conjunction of multiple patterns with a positive lookahead (e.g. ^[1-6]+$ and ^[4-9]+$ would become (?=^[1-6]+$)^[4-9]+$). But that only works correctly when all patterns are fully anchored. So maybe add some kind of WARN log for this?

What do you think?

Here's my work-in-progress, just for reference #4811