Automatically determine multipleOf from `Digits` constraint

[Postremus]

Right now to document and validate a bigdecimal field with a specific count of fractions I have to write something like this:

@Schema(multipleOf = 0.001)
@Digits(integer = 5, fraction = 3)
@Min(0)
@DecimalMax("99999.999")
public BigDecimal width;

Could maybe the @Schema(multipleOf = 0.001) automaticaly be determined if not specified otherwise?
E.g. @Digits(integer = 5, fraction = 3) -> @Schema(multipleOf = 0.001)

This would, in my opinion, at least cover the most common case where multipleOf is simply used to explicitily state in the doc the fraction count.

[MikeEdgar]

Are you getting the pattern constraint generated on the schema for this example currently?

[Postremus]

Yes

[Postremus]

@MikeEdgar
However why is the pattern even generated?

@Schema(examples = "12345.678", multipleOf = 0.001)
    @Digits(integer = 5, fraction = 3)
    @Min(0)
    @DecimalMax("99999.999")
public BigDecimal width;

generates following property in the openapi yaml:

"width" : {
            "type" : "number",
            "multipleOf" : 0.001,
            "examples" : [ 12345.678 ],
            "maximum" : 99999.999,
            "pattern" : "^\\d{1,5}([.]\\d{1,3})?$",
            "minimum" : 0
          },

AFAIK pattern can not apply to string.
https://json-schema.org/draft/2020-12/json-schema-validation#section-6.3.3
pattern is a keyword for string, not for any other type.

[MikeEdgar]

pattern is a keyword for string, not for any other type

Right, I agree. It seems your idea of using multipleOf should be a viable replacement/fix for that.