Zod Utilz

Framework agnostic utilities for Zod

Purpose
Contribute
Yet another library
Installation
- From npm (Node/Bun)
Getting Started
- import
Utilz
TODO

Purpose

Simplify common tasks in Zod
Fill the gap of features that might be missing in Zod
Provide implementations for potential new features in Zod

Contribute

Always open to ideas. Positive or negative, all are welcome. Feel free to contribute an issue or PR.

Yet another library

You might not want to install yet another library only to get access to that one Util you need. No worries. Feel free to copy and paste the code you need into your project. It won't get updated when this library gets updated, but it will reduce your bundle size. :D

Perhaps in the future there will be a way to install only the Utilz you need. If you know how to do this, please let me know.

Installation

From npm (Node/Bun)

npm install zod_utilz
yarn add zod_utilz
pnpm add zod_utilz
bun add zod_utilz

Getting Started

import

Node/Bun

import { zu } from 'zod_utilz'

Deno

import { zu } from 'https://deno.land/x/zod_utilz/mod.ts'
// or
import { zu } from 'npm:zod_utilz'

Utilz

SPR

SPR stands for SafeParseResult

This enables optional chaining or nullish coalescing for z.SafeParseReturnType.

import { zu } from 'zod_utilz'
const schema = z.object( { foo: z.string() } )
const result = zu.SPR( schema.safeParse( { foo: 42 } ) )
const fooDataOrErrors = result.data?.foo ?? result.error?.format().foo?._errors

makeErrorMap

Simplifies the process of making a ZodErrorMap

import { zu } from 'zod_utilz'

const errorMap = zu.makeErrorMap( {
    required: 'Custom required message',
    invalid_type: ( { data } ) => `${ data } is an invalid type`,
    too_big: ( { maximum } ) => `Maximum length is ${ maximum }`,
    invalid_enum_value: ( { data, options } ) =>
        `${ data } is not a valid enum value. Valid options: ${ options?.join( ' | ' ) } `,
} )

const stringSchema = z.string( { errorMap } ).max( 32 )

zu.SPR( stringSchema.safeParse( undefined ) ).error?.issues[ 0 ].message
// Custom required message

zu.SPR( stringSchema.safeParse( 42 ) ).error?.issues[ 0 ].message
// 42 is an invalid type

zu.SPR( stringSchema.safeParse( 'this string is over the maximum length' ) ).error?.issues[ 0 ].message
// Maximum length is 32

const enumSchema = z.enum( [ 'foo', 'bar' ], { errorMap } )

zu.SPR( enumSchema.safeParse( 'baz' ) ).error?.issues[ 0 ].message
// baz is not a valid enum value. Valid options: foo | bar

useTypedParsers

Enables compile time type checking for zod parsers.

import { zu } from 'zod_utilz'
const schemaWithTypedParsers = zu.useTypedParsers( z.literal( 'foo' ) )

schemaWithTypedParsers.parse( 'foo' )
// no ts errors

schemaWithTypedParsers.parse( 'bar' )
//                            ^^^^^
// Argument of type '"bar"' is not assignable to parameter of type '"foo"'

coerce

Coercion that treats errors like normal zod errors. Prevents throwing errors when using safeParse.

z.bigint()

import { zu } from 'zod_utilz'
const bigintSchema = zu.coerce( z.bigint() )
bigintSchema.parse( '42' ) // 42n
bigintSchema.parse( '42n' ) // 42n
zu.SPR( bigintSchema.safeParse( 'foo' ) ).error?.issues[ 0 ].message
// 'Expected bigint, received string'

z.boolean()

import { zu } from 'zod_utilz'
const booleanSchema = zu.coerce( z.boolean() )

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean
// only exception to normal boolean coercion rules
booleanSchema.parse( 'false' ) // false

// https://developer.mozilla.org/en-US/docs/Glossary/Falsy
// falsy => false
booleanSchema.parse( false ) // false
booleanSchema.parse( 0 ) // false
booleanSchema.parse( -0 ) // false
booleanSchema.parse( 0n ) // false
booleanSchema.parse( '' ) // false
booleanSchema.parse( null ) // false
booleanSchema.parse( undefined ) // false
booleanSchema.parse( NaN ) // false

// truthy => true
booleanSchema.parse( 'foo' ) // true
booleanSchema.parse( 42 ) // true
booleanSchema.parse( [] ) // true
booleanSchema.parse( {} ) // true

z.number().array()

import { zu } from 'zod_utilz'
const numberArraySchema = zu.coerce( z.number().array() )

// if the value is not an array, it is coerced to an array with one coerced item
numberArraySchema.parse( 42 ) // [ 42 ]
numberArraySchema.parse( '42' ) // [ 42 ]

// if the value is an array, it coerces each item in the array
numberArraySchema.parse( [] ) // []
numberArraySchema.parse( [ '42', 42 ] ) // [ 42, 42 ]

zu.SPR( numberArraySchema.safeParse( 'foo' ) ).error?.issues[ 0 ].message
// 'Expected number, received nan'

useURLSearchParams

A way to parse URLSearchParams

import { zu } from 'zod_utilz'
const schema = zu.useURLSearchParams(
    z.object( {
        string: z.string(),
        number: z.number(),
        boolean: z.boolean(),
    } )
)

zu.SPR( schema.safeParse(
    new URLSearchParams( {
        string: 'foo',
        number: '42',
        boolean: 'false',
    } )
) ).data
// { string: 'foo', number: 42, boolean: false }

zu.SPR( schema.safeParse(
    new URLSearchParams( {
        string: '42',
        number: 'false',
        boolean: 'foo',
    } )
) ).error?.flatten().fieldErrors
// {
//     string: [ 'Expected string, received number' ],
//     number: [ 'Expected number, received boolean' ],
//     boolean: [ 'Expected boolean, received string' ],
// }

useFormData

A way to parse FormData

import { zu } from 'zod_utilz'
const schema = zu.useFormData(
    z.object( {
        string: z.string(),
        number: z.number(),
        boolean: z.boolean(),
        file: z.instanceof( File ),
    } )
)

const formData = new FormData()
formData.append( 'string', 'foo' )
formData.append( 'number', '42' )
formData.append( 'boolean', 'false' )
formData.append( 'file', new File( [], 'filename.ext' ) )

zu.SPR( schema.safeParse( formData ) ).data,
// { string: 'foo', number: 42, boolean: false, file: File }

const formData = new FormData()
formData.append( 'string', '42' )
formData.append( 'number', 'false' )
formData.append( 'boolean', 'foo' )
formData.append( 'file', 'filename.ext' )

zu.SPR( schema.safeParse( formData ) ).error?.flatten().fieldErrors,
// {
//     string: [ 'Expected string, received number' ],
//     number: [ 'Expected number, received boolean' ],
//     boolean: [ 'Expected boolean, received string' ],
//     file: [ 'Input not instance of File' ],
// }

partialSafeParse

partialSafeParse allows you to get the valid fields even if there was an error in another field

import { zu } from 'zod_utilz'
const userSchema = z.object( { name: z.string(), age: z.number() } )
const result = zu.partialSafeParse( userSchema, { name: null, age: 42 } )
// {
//     successType: 'partial',
//     validData: { age: 42 },
//     invalidData: { name: null },
// }
result.error?.flatten().fieldErrors
// { name: [ 'Expected string, received null' ] }

json

zu.json() is a schema that validates that a JavaScript object is JSON-compatible. This includes string, number, boolean, and null, plus Arrays and Objects containing JSON-compatible types as values

import { zu } from 'zod_utilz'
const schema = zu.json()
schema.parse( false ) // false
schema.parse( 8675309 ) // 8675309
schema.parse( { a: 'deeply', nested: [ 'JSON', 'object' ] } )
// { a: 'deeply', nested: [ 'JSON', 'object' ] }

stringToJSON

zu.stringToJSON() is a schema that validates JSON encoded as a string, then returns the parsed value

import { zu } from 'zod_utilz'
const schema = zu.stringToJSON()
schema.parse( 'true' ) // true
schema.parse( 'null' ) // null
schema.parse( '["one", "two", "three"]' ) // ['one', 'two', 'three']
schema.parse( '<html>not a JSON string</html>' ) // throws

TODO