how to use typebox with ajv.addKeyword and ajv async validation ?

[noor-tg]

Hi,
I am trying to use typebox with ajv to validate user name to users table. so I need to make async validation with ajv. as I build the schema rules with typebox . I could not find any information about how to handle this case.

here is example of how I prepare typebox and ajv to handle this case (excluding how to handle the question part)

const userSchema = Type.Object(
  {
    id: Type.Number(),
    name: Type.String({ minLength: 3 }),
    password: Type.Optional(Type.String({ minLength: 3 }))
  },
  {
    $id: 'User',
    $async: true,
    additionalProperties: false
  }
)

const ajv = new Ajv({
  allErrors: true,
  messages: false
})

ajv.addKeyword({
  keyword: 'unique',
  type: 'string',
  async: true,
  validate: async (schema: any, data: any) => {
    logger.info(schema, data)
    const exists = await knex.table(schema.table).where(schema.field).first()
    return !!exists
  }
})

const dataValidator: Ajv = new Ajv()

const validate = dataValidator.compile(userSchema)

try {
   const result = await validate({name: 'somestring' })
} catch(e) {
// error about unique name should be shown here
}

when I try to change it like:

const userSchema = Type.Object(
  {
    id: Type.Number(),
    name: Type.String({ minLength: 3, unique: {table: "users", field: "name"} }),
    password: Type.Optional(Type.String({ minLength: 3 }))
  },
  {
    $id: 'User',
    $async: true,
    additionalProperties: false
  }
)

I see error

Error: strict mode: unknown keyword: "unique"

[sinclairzx81]

@Nour-DEV Hi,

This is more an Ajv question than a TypeBox question. However to make this work, you need to configure the unique keyword on the same instance as you're using to validate. In the example provided, you configured the unique keyword on the ajv instance, but then created a new instance dataValidator which wasn't configured for the keyword.

The following should resolve things

import { Type } from '@sinclair/typebox'
import Ajv from 'ajv'

const userSchema = Type.Object(
  {
    id: Type.Number(),
    name: Type.String({ minLength: 3, unique: {table: "users", field: "name"} }),
    password: Type.Optional(Type.String({ minLength: 3 }))
  },
  {
    $id: 'User',
    $async: true,
    additionalProperties: false
  }
)

const ajv = new Ajv({
  allErrors: true,
  messages: false
})
ajv.addKeyword({
  keyword: 'unique',
  type: 'string',
  async: true,
  validate: async (schema: any, data: any) => {
    logger.info(schema, data)
    const exists = await knex.table(schema.table).where(schema.field).first()
    return !!exists
  }
})

 // const validate = dataValidator.compile(userSchema) // incorrect

 const validate = ajv.compile(userSchema)              // correct

try {
   const result = await validate({name: 'somestring' })
} catch(e) {
// error about unique name should be shown here
}

Hope this helps
S

[noor-tg]

Thank you.
But even with your changes it did not work.
I will try to make reproduction repository for it . And share it with you.

[noor-tg]

So I tried to make reproduction repo to check it in isolation. And it is working.

Thank you