string-schemas-length-defined

String schemas length defined

Authors:

• adamaltman Adam Altman (Redocly)

What this does and why

This requires minLength and maxLength properties set on a string where enum isn't defined.

Code

The rule checks that a string uses the minLength and maxLength keywords unless an enum is defined.

It does this by using a combination requireAny and mutuallyRequired.

  rule/string-schemas-length-defined:
    subject: 
      type: Schema
    where: 
      - subject: 
          type: Schema
          property: type
        assertions:  
          const: string
    assertions: 
      requireAny: 
        - minLength
        - maxLength
        - enum
      mutuallyRequired: 
        - minLength
        - maxLength

Examples

The following OpenAPI has schemas prefixed with either Good or Bad to show the configurable rules catch the likely bad uses of keywords.

openapi: 3.1.0
info: 
  title: For testing strict string definitions
  version: 1.0.0
paths: {}
components: 
  schemas: 

    LuckyNumber: # should not be caught be these rules
      type: integer

    BadString:
      type: string

    BadStringWithMinLength:
      type: string
      minLength: 1

    BadStringWithMaxLength:
      type: string
      maxLength: 64
    
    GoodStringBecauseEnum:
      type: string
      enum:
        - ABC
        - DEF
        - GHI

    GoodStringBecauseMinAndMaxLength:
      type: string
      minLength: 1
      maxLength: 64

References

Inspired by a question from Keith F.