no-schema-type-mismatch

Ensures that a schema's structural properties match its declared type. In particular:

• Only a schema of type array may include an items field.
• Only a schema of type object may include a properties field.

The rule checks only schemas whose type is a single value. Schemas with a list of types, such as type: [string, 'null'], are not checked.

When designing an API schema, the defined type should be consistent with its structure:

• Objects are collections of key/value pairs. They should be defined using properties (or additionalProperties) and must not use items.
• Arrays are ordered lists of items and must use items to define their content. Including properties is invalid.
• Primitive types (string, number, integer, boolean, null) have neither properties nor items.

This rule helps catch typos and misconfigurations early in your API definition.

Example configuration:

rules:
  no-schema-type-mismatch: error

properties:
  user:
    type: object
    properties:
      id:
        type: string
    items:
      type: number

Error: An object type should not include an items field.

properties:
  tags:
    type: array
    properties:
      name:
        type: string

Error: An array type should not include a properties field.

properties:
  notification_email:
    type: string
    properties:
      address:
        type: string

Error: A string type should not include a properties field.

properties:
  user:
    type: object
    properties:
      id:
        type: string
      name:
        type: string

properties:
  tags:
    type: array
    items:
      type: string

• no-enum-type-mismatch
• no-mixed-number-range-constraints
• no-required-schema-properties-undefined
• configurable rules
• no-invalid-media-type-examples
• no-invalid-parameter-examples
• no-invalid-schema-examples

• Rule source