Is there any alternative ajv(json-schema validator) for deno?

Question

I'm looking for a ajv-like json schema validator for deno. Wondering is there any alternative?

Answer 1

You have some options to use none-deno modules.

The easiest way is to use a service like esm.sh and import it like:

import Ajv from 'https://esm.sh/ajv@8.6.1';
import addFormats from 'https://esm.sh/ajv-formats@2.1.0';
const ajv = new Ajv({allErrors: true});
addFormats(ajv);

esm.sh even provides .d.ts definitions if available, so you can import types as well.

import Ajv, {ValidateFunction} from 'https://esm.sh/ajv@8.6.1';
const validate: ValidateFunction = new Ajv().compile(schema);

In some cases, you can even import the raw typescript file directly from git. But Ajv imports json files directly, which deno does not support atm.

Answer 2

You don't need an alternative, you can use ajv.

Ajv provides a bundle for browsers: https://cdnjs.cloudflare.com/ajax/libs/ajv/6.12.2/ajv.min.js

All you need to do is download it, save it to your project and add: export default Ajv at the bottom of the file.

ajv.js

/* ajv 6.12.2: Another JSON Schema Validator */
!function(e){if("object"==typeof exports&&"undefined"!=typeof module) /*....... */
//# sourceMappingURL=ajv.min.js.map

export default Ajv;

index.js

import Ajv from './ajv.js'

const ajv = new Ajv({allErrors: true});

const schema = {
  "properties": {
    "foo": { "type": "string" },
    "bar": { "type": "number", "maximum": 3 }
  }
};

function test(data) {
  const valid = validate(data);
  if (valid) console.log('Valid!');
  else console.log('Invalid: ' + ajv.errorsText(validate.errors));
}


const validate = ajv.compile(schema);

test({"foo": "abc", "bar": 2});
test({"foo": 2, "bar": 4});

---

Remember that Deno is a JavaScript runtime, so any code which uses plain JavaScript, you'll be able to use it with very little modification, in this case just export default Ajv

Answer 3

Till now, ajv-like schema validator is not available for Deno. However, you can try value_schema for schema validation. It has both Node.js and Deno versions.

Answer 4

jtd is a viable alternative. It is a deno native implementation of JSON Type Definition, aka RFC 8927, which is an alternative to json-schema validation (and thus ajv) but has a similar purpose.