string

A string. The empty string '' is treated as a missing value.

Signature

function string(msg?: Message): Schema<string>

Parameters

Parameter	Type	Description
msg	Message	Custom message. Replaces the default messages for all errors of this schema

Accepts

Any non-empty string. Numbers are not converted to strings — use coerce.string for that.

undefined, null and '' are treated as empty — see Empty values.

Error codes

Code	When	Default message
required	The value is empty	Required
string	Not a string	Must be a string

You can change the texts: see Messages & i18n.

Notes

A whitespace-only string ' ' passes. To reject it: pipe(string(), trim(), minLength(1)).

To allow an empty string as a value: optional(string(), '').

Example

Required field with rules

const name = pipe(string('Please enter your name'), trim(), minLength(2), maxLength(50));

validate(name, '');       // Please enter your name
validate(name, ' Ann ');  // valid, data: 'Ann'

See also

• pipe — add rules
• coerce.string — numbers to strings
• Empty values