# schema-required-properties-defined

Source: https://apigenie.pl/docs/linter/swagger/rules/schema-required-properties-defined

This rule checks that every name listed in `required` is declared in
`properties`.

## Rule Details

A required property which is not declared is usually a typo
(`required: [nmae]`) or a property removed from `properties` but not from
`required`. Its value is not described, and generated code often cannot
represent it.

The `schema-required-properties-defined` rule checks every schema of a
Swagger 2.0 document that has a `required` list. It looks for the declaration
of each name wherever the value of the schema is also described:

- in the `properties` of the schema itself,
- in its `allOf` members, following references,
- in the schemas it is an `allOf` member of, and in their other members.

For every name that is not declared, it reports `Required property '<name>'
is not defined in 'properties'`.

Schemas which may allow undeclared properties on purpose are skipped: when a
schema of the group has a schema in `additionalProperties` (a map) or
`additionalProperties: true`. Schemas whose group contains a reference that
cannot be resolved are skipped too.

`required` in a schema that declares types (itself or through its `allOf`
members) none of which is `object`, for example beside `items` in an array
schema instead of inside it, has no effect. The rule reports it with
`'required' has no effect because the schema does not allow objects`.

## Configuration

None.

## Examples

**Good**. `name` is declared by the `allOf` member `Named`.

```yaml
swagger: '2.0'
info:
  title: Pets
  version: 1.0.0
paths: {}
definitions:
  Named:
    type: object
    properties:
      name:
        type: string
  Pet:
    allOf:
      - $ref: '#/definitions/Named'
      - type: object
        required: [name, age]
        properties:
          age:
            type: integer
```

**Bad**. `nmae` is not declared.

```yaml
swagger: '2.0'
info:
  title: Pets
  version: 1.0.0
paths: {}
definitions:
  Pet:
    type: object
    required: [nmae]
    properties:
      name:
        type: string
```

**Bad**. `required` applies to the array, not to its items.

```yaml
swagger: '2.0'
info:
  title: Pets
  version: 1.0.0
paths: {}
definitions:
  Pets:
    type: array
    required: [name]
    items:
      type: object
      properties:
        name:
          type: string
```

## When Not to Use It

Disable this rule when required properties are intentionally left
undescribed.

## Compatibility

This rule is compatible with Swagger 2.0 documents. OpenAPI 3.x documents are
linted by the OpenAPI linter, which has a rule of the same name.