yup

The module export.

// core schema
import {
  mixed,
  string,
  number,
  boolean,
  bool,
  date,
  object,
  array,
  ref,
  lazy,
} from 'yup';

// Classes
import {
  Schema,
  MixedSchema,
  StringSchema,
  NumberSchema,
  BooleanSchema,
  DateSchema,
  ArraySchema,
  ObjectSchema,
} from 'yup';

// Types
import type { InferType, ISchema, AnySchema, AnyObjectSchema } from 'yup';

reach(schema: Schema, path: string, value?: object, context?: object): Schema

For nested schemas, reach will retrieve an inner schema based on the provided path.

For nested schemas that need to resolve dynamically, you can provide a value and optionally a context object.

import { reach } from 'yup';

let schema = object({
  nested: object({
    arr: array(object({ num: number().max(4) })),
  }),
});

reach(schema, 'nested.arr.num');
reach(schema, 'nested.arr[].num');
reach(schema, 'nested.arr[1].num');
reach(schema, 'nested["arr"][1].num');

addMethod(schemaType: Schema, name: string, method: ()=> Schema): void

Adds a new method to the core schema types. A friendlier convenience method for schemaType.prototype[name] = method.

import { addMethod, date } from 'yup';

addMethod(date, 'format', function format(formats, parseStrict) {
  return this.transform((value, originalValue, ctx) => {
    if (ctx.isType(value)) return value;

    value = Moment(originalValue, formats, parseStrict);

    return value.isValid() ? value.toDate() : new Date('');
  });
});

If you want to add a method to ALL schema types, extend the abstract base class: Schema

import { addMethod, Schema } from 'yup';

addMethod(Schema, 'myMethod', ...)

ref(path: string, options: { contextPrefix: string }): Ref

Creates a reference to another sibling or sibling descendant field. Refs are resolved at validation/cast time and supported where specified. Refs are evaluated in the proper order so that the ref value is resolved before the field using the ref (be careful of circular dependencies!).

import { ref, object, string } from 'yup';

let schema = object({
  baz: ref('foo.bar'),
  foo: object({
    bar: string(),
  }),
  x: ref('$x'),
});

schema.cast({ foo: { bar: 'boom' } }, { context: { x: 5 } });
// => { baz: 'boom',  x: 5, foo: { bar: 'boom' } }

lazy((value: any) => Schema): Lazy

Creates a schema that is evaluated at validation/cast time. Useful for creating recursive schema like Trees, for polymorphic fields and arrays.

CAUTION! When defining parent-child recursive object schema, you want to reset the default() to null on the child—otherwise the object will infinitely nest itself when you cast it!

let node = object({
  id: number(),
  child: yup.lazy(() => node.default(undefined)),
});

let renderable = yup.lazy((value) => {
  switch (typeof value) {
    case 'number':
      return number();
    case 'string':
      return string();
    default:
      return mixed();
  }
});

let renderables = array().of(renderable);

ValidationError(errors: string | Array<string>, value: any, path: string)

Thrown on failed validations, with the following properties

• name: "ValidationError"
• path: a string, indicating where there error was thrown. path is empty at the root level.
• errors: array of error messages
• inner: in the case of aggregate errors, inner is an array of ValidationErrors throw earlier in the validation chain. When the abortEarly option is false this is where you can inspect each error thrown, alternatively, errors will have all of the messages from each inner error.