is

Checks if the input matches the scheme.

By using a type predicate, this function can be used as a type guard.

const result = is<TSchema>(schema, input, config);

Generics

• TSchema extends BaseSchema

Parameters

• schema TSchema
• input unknown
• config Pick<SchemaConfig, 'skipPipe'> | undefined

Returns

• result boolean

Example

The following example show how is can be used.

const EmailSchema = string([email()]);
const data: unknown = 'jane@example.com';

if (is(EmailSchema, data)) {
  const email = data; // string
}

Related

The following APIs can be combined with is.

Schemas

• any,
• array,
• bigint,
• blob,
• boolean,
• date,
• enum_,
• instance,
• intersect,
• lazy,
• literal,
• map,
• nan,
• never,
• nonNullable,
• nonNullish,
• nonOptional,
• null_,
• nullable,
• nullish,
• number,
• object,
• optional,
• picklist,
• record,
• set,
• special,
• string,
• symbol,
• tuple,
• undefined_,
• union,
• unknown,
• variant,
• void_

Methods

• brand,
• coerce,
• fallback,
• keyof,
• merge,
• omit,
• partial,
• pick,
• required,
• transform,
• unwrap