FieldValidation

Creates a Validation that checks if a number falls within a specified inclusive range.

(
  min: number,
  max: number,
  message?: ValidationMessage<number>
): Validation<number>

Creates a Validation that checks if a string is a valid email format.

(message: ValidationMessage<string>): Validation<string>

Creates a Validation that checks if a string ends with a specified suffix.

(
  suffix: string,
  message?: ValidationMessage<string>
): Validation<string>

Creates a Validation that checks if a string exactly matches an expected value.

(
  expected: string,
  message?: ValidationMessage<string>
): Validation<string>

Creates a Validation that checks if a string contains a specified substring.

(
  substring: string,
  message?: ValidationMessage<string>
): Validation<string>

Creates a Validation that checks if a number is a whole number (integer).

(message: ValidationMessage<number>): Validation<number>

Creates a tagged union of field states (NotValidated, Validating, Valid, Invalid) for a given value schema.

Creates a Validation that checks if a number is less than or equal to a maximum value.

(
  num: number,
  message?: ValidationMessage<number>
): Validation<number>

Creates a Validation that checks if a string does not exceed a maximum length.

(
  max: number,
  message?: ValidationMessage<string>
): Validation<string>

Creates a Validation that checks if a number is greater than or equal to a minimum value.

(
  num: number,
  message?: ValidationMessage<number>
): Validation<number>

Creates a Validation that checks if a string meets a minimum length.

(
  min: number,
  message?: ValidationMessage<string>
): Validation<string>

Creates a Validation that checks if a number is zero or greater.

(message: ValidationMessage<number>): Validation<number>

Creates a Validation that checks if a string is one of a specified set of allowed values.

(
  values: readonly Array<string>,
  message?: ValidationMessage<string>
): Validation<string>

Creates a Validation that checks if a string matches a regular expression.

(
  regex: RegExp,
  message: ValidationMessage<string>
): Validation<string>

Creates a Validation that checks if a number is greater than zero.

(message: ValidationMessage<number>): Validation<number>

Creates a Validation that checks if a string is non-empty.

(message: ValidationMessage<string>): Validation<string>

Creates a Validation that checks if a string begins with a specified prefix.

(
  prefix: string,
  message?: ValidationMessage<string>
): Validation<string>

Creates a Validation that checks if a string is a valid URL format.

(message: ValidationMessage<string>): Validation<string>

A tuple of a predicate and error message used for field validation.

type Validation = [Predicate.Predicate<T>, ValidationMessage<T>]

An error message for a validation rule — either a static string or a function that receives the invalid value.

type ValidationMessage = string | (value: T) => string