# schema-enum-types

Source: https://apigenie.pl/docs/linter/swagger/rules/schema-enum-types

This rule ensures that all values of an `enum` list match the declared
`type`.

## Rule Details

An enum value that does not match the type can never be valid, and usually
indicates a mistake in either the type or the values.

The `schema-enum-types` rule checks every typed object of a Swagger 2.0
document that has an `enum` list: schemas, non-body parameters, response
headers and `items` objects (objects with a `$ref` are checked where they are
defined). It reports `Enum value type is not in the schema type` when the
object has no `type`, or when at least one value does not match it:

- `string` accepts strings,
- `integer` accepts integral numbers,
- `number` accepts integral and fractional numbers,
- `boolean` accepts `true` and `false`,
- `array` accepts arrays,
- `object` accepts objects.

Swagger 2.0 has no `null` type, so `null` never matches, and no value matches
the `file` type.

## Configuration

None.

## Examples

**Good**.

```yaml
swagger: '2.0'
info:
  title: Tasks
  version: 1.0.0
paths: {}
definitions:
  Status:
    type: string
    enum: [OPEN, CLOSED]
  Ratio:
    type: number
    enum: [1, 2.5]
```

**Bad**. The values of `Priority` are integers, and `Status` has no type.

```yaml
swagger: '2.0'
info:
  title: Tasks
  version: 1.0.0
paths: {}
definitions:
  Priority:
    type: string
    enum: [1, 2, 3]
  Status:
    enum: [OPEN, CLOSED]
```

## Automatic fixes

When invoked with `--fix`, this rule sets the `type` of a reported object to
the type of its enum values, provided that all values have the same type (and
are not `null`) and the object has no `format`. In the "Bad" example above,
`Priority` gets `type: integer` and `Status` gets `type: string`. Objects
mixing values of different types are not fixed.

## When Not to Use It

There is no good reason to keep enum values that do not match the type, so
this rule should always be enabled.

## 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.