const AJV = require('ajv');
const fastUri = require('fast-uri');
const ajv = new AJV({
  uriResolver: fastUri // comment this line to see it works with uri-js
});

const schema = {
  $ref: "#/definitions/Record%3Cstring%2CPerson%3E",
  definitions: {
    Person: {
      type: "object",
      properties: {
        firstName: {
          type: "string",
        },
      },
    },
    "Record<string,Person>": {
      type: "object",
      additionalProperties: {
        $ref: "#/definitions/Person",
      },
    },
  },
};

const data = {
  joe: {
    firstName: "Joe",
  },
};

const validate = ajv.compile(schema); // throws with fast-uri
console.log(validate(data));