Typed schema based validation with low calories
Really simple and lightweight validation library for JavaScript. Used by @adonisjs/env for validating environment variables.
Install the module from npm registry as follows:
npm install @poppinss/validator-lite
# yarn
yarn add @poppinss/validator-lite
# pnpm
pnpm add @poppinss/validator-lite
The following example shows how to use the validator :
import { schema } from '@poppinss/validator-lite'
/**
* Define a schema
*/
const userSchema = {
name: schema.string(),
age: schema.number(),
email: schema.string.optional(),
website: schema.string({ format: 'url' }),
}
/**
* Define the data
*/
const data = {
name: 'John doe',
age: 25,
website: 'https://adonisjs.com',
}
/**
* Validate the data
*/
for (let [key, fn] of Object.entries(userSchema)) {
fn(key, user[key])
}
Following is the list of available methods :
Validates the value to check if it exists and if it is a valid string. Empty strings fail the validations, and you must use the optional variant to allow empty strings.
{
APP_KEY: schema.string()
}
// Mark it as optional
{
APP_KEY: schema.string.optional()
}
You can also force the value to have one of the pre-defined formats.
// Must be a valid host (url or ip)
schema.string({ format: 'host' })
// Must be a valid URL
schema.string({ format: 'url' })
// Must be a valid email address
schema.string({ format: 'email' })
// Must be a valid UUID
schema.string({ format: 'uuid' })
When validating the url
format, you can also define additional options to force/ignore the tld
and protocol
.
schema.string({ format: 'url', tld: false, protocol: false })
Enforces the value to be a valid string representation of a boolean. Following values are considered as valid booleans and will be converted to true
or false
.
'1', 'true'
are casted toBoolean(true)
'0', 'false'
are casted toBoolean(false)
{
CACHE_VIEWS: schema.boolean()
}
// Mark it as optional
{
CACHE_VIEWS: schema.boolean.optional()
}
Enforces the value to be a valid string representation of a number.
{
PORT: schema.number()
}
// Mark it as optional
{
PORT: schema.number.optional()
}
Forces the value to be one of the pre-defined values.
{
MY_ENUM: schema.enum(['development', 'production'] as const)
}
// Mark it as optional
{
MY_ENUM: schema.enum.optional(['development', 'production'] as const)
}
For every other validation use case, you can define your custom functions.
{
PORT: (key, value) => {
if (!value) {
throw new Error('Value for PORT is required')
}
if (isNaN(Number(value))) {
throw new Error('Value for PORT must be a valid number')
}
return Number(value)
}
}
- Make sure to always return the value after validating it.
- The return value can be different from the initial input value.