minLength

Creates a min length validation action.

const Action = v.minLength<TInput, TRequirement, TMessage>(
  requirement,
  message
);

Generics

• TInput extends LengthInput
• TRequirement extends number
• TMessage extends ErrorMessage<MinLengthIssue<TInput, TRequirement>> | undefined

Parameters

• requirement TRequirement
• message TMessage

Explanation

With minLength you can validate the length of a string or array. For strings, length is measured like JavaScript's value.length, i.e. by UTF-16 code units. For arrays, length is measured by the number of items. If the input does not match the requirement, you can use message to customize the error message.

If you need to validate the minimum number of user-perceived characters, use minGraphemes instead. If you need to count each Unicode code point as a single character (a supplementary code point occupies two UTF-16 code units in JavaScript), use minCodePoints instead.

Returns

• Action MinLengthAction<TInput, TRequirement, TMessage>

Examples

The following examples show how minLength can be used.

Minimum string length

Schema to validate a string with a minimum length of 3 UTF-16 code units.

const MinStringSchema = v.pipe(
  v.string(),
  v.minLength(3, 'The string must be 3 or more UTF-16 code units long.')
);

Minimum array length

Schema to validate an array with a minimum length of 5 items.

const MinArraySchema = v.pipe(
  v.array(v.number()),
  v.minLength(5, 'The array must contain 5 numbers or more.')
);

Related

The following APIs can be combined with minLength.

Schemas

any, array, custom, instance, string, tuple, unknown

Methods

pipe

Actions

minCodePoints, minGraphemes

Utils

isOfKind, isOfType