class Schemaclass

class Builder

A class that represents a validation builder for an input value.

class Builder<T = any>;

Notes

• Returned by Schema.build methods, e.g. f.string().
• Provides a fluent interface for adding default values, validation checks, transformations, and error messages.

Examples

f.string()
  .optional()               // Allow undefined
  .nullable()               // Allow null
  .default("fallback")      // Provide default value
  .check(s => s.length > 0) // Custom validation
  .error("Cannot be empty") // Custom error message
  .transform(s => s.trim()) // Transform the value
  .required("Required")     // Require non-empty value

Instance members

• [
  The Standard Schema v1 compliance property.
• values
  The accepted literal values, for a literal value validator only.
• shape
  The accepted object properties, for an object validator only.
• default()
  Sets a default value.
• optional()
  Marks the value as optional, allowing undefined values.
• nullable()
  Marks the value as nullable, allowing null values but not undefined.
• required()
  Adds a required check (not null, undefined, NaN, or empty string).
• check()
  Adds a validation check using the provided function.
• error()
  Sets the error message for the previously failed check(s).
• refine()
  Adds a refinement check; shorthand for check followed by error.
• transform()
  Transforms the value using the provided callback function.
• preprocess()
  Replaces the input value using the provided callback function.

Related

• class Schema
  A class that represents a validation schema for input values, objects, and arrays.