How do I add a custom format for a fastify's ajv instance?

[budarin]

💬 Question here

I want to add support for extended types that are implemented in the ajv-formats package
I am trying to perform ajv initialization and describe the formats

const app = Fastify({
    ajv: {
      plugins: [require('ajv-formats']
    },
});

the scheme:

{
  "type": "object",
  "properties": {
     "id": { 
        "type" "uuid" 
     }
  }
}

but get an error:

    unknown format "uuid" ignored in schema at path "#/properties/id"

      at unknownFormat (node_modules/ajv/lib/vocabularies/format/format.ts:87:15)
      at validateFormat (node_modules/ajv/lib/vocabularies/format/format.ts:75:9)
      at Object.code (node_modules/ajv/lib/vocabularies/format/format.ts:40:10)
      at keywordCode (node_modules/ajv/lib/compile/validate/index.ts:523:9)
      at node_modules/ajv/lib/compile/validate/index.ts:265:9
      at CodeGen.code (node_modules/ajv/lib/compile/codegen/index.ts:525:33)
      at CodeGen.block (node_modules/ajv/lib/compile/codegen/index.ts:680:20)
      at iterateKeywords (node_modules/ajv/lib/compile/validate/index.ts:262:7)
      at groupKeywords (node_modules/ajv/lib/compile/validate/index.ts:241:7)
      at node_modules/ajv/lib/compile/validate/index.ts:233:38

the same result I get using this code

const app = Fastify({
    ajv: {
        customOptions: {
          formats: {
             uuid: {
               type: 'string',
               validate: /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$'/,
             },
          },
        },
    },
});

how can I use custom formats in fastify?

Environment

• node version: v18.6.0
• fastify version: ^4.4.0
• os: any

[Uzlopak]

Well. formats are not new types. formats are formats. Maybe you should also open a issue in ajv, that they should not have an error-message unknown format "uuid" ignored in schema if in fact the type is unknown.

{
  "type": "object",
  "properties": {
     "id": { 
        "type": "string",
        "format" "uuid" 
     }
  }
}

[budarin]

@Uzlopak

there was a banal typo - I just missed writing {type: 'strin'} when writing the issue

with a properly designed scheme, this error is reproduced - so the question remains open

[Uzlopak]

I added a unit test to fastify. It seems that ajv-formats work as expected:

https://github.com/fastify/fastify/pull/4187/files

[budarin]

I don't understand anything - I do everything the same, but I get an error...

[budarin]

I have found the problem - it affected by another of ajv instance in app - I have another ajv instance to validate response from fetch to external resources and its presence somehow affects the instance in fastify

[budarin]

exactly the problem is in a parallel instance - if I initialize ajv-formats for it:

import Ajv from 'ajv';
import addFormats from 'ajv-formats';

const ajv = new Ajv();
addFormats(ajv);

const app = Fastify({
    ajv: {
      plugins: [addFormats]
    },
});

...

then the error does not occur, but if you do not add formats to this instance and add them to the ajv instance in fastify, an error occurs

in which package should I write issue: fastify or ajv?

[budarin]

it seems that my question is specific to our project and justify has no problems in ajv-formats - so I close this issue