Ajv Issue

const Ajv = require("ajv/dist/2019") ajv = new Ajv({ $data: true, useDefaults: true, allErrors: true, verbose: true, strict: false }); const schema = { "$schema": "https://json-schema.org/draft/2019-09/schema#", "type": "object", "properties": { "testFields": { "type": "array", "minItems": 1, "contains": { "properties": { "lastUpdatedAtTime": { "const": true } } }, "minContains": 1, "maxContains": 1, "items": { "type": "object", "properties": { "name": { "description": "", "type": "string" }, "lastUpdatedAtTime": { "description": "", "type": "boolean", "default": false } }, "additionalProperties": false }, "uniqueItemProperties": [ "name" ] } } }; const data = { "testFields": [ { "name": "test1", "lastUpdatedAtTime": true }, { "name": "test2", "lastUpdatedAtTime": false }, { "name": "test3", "lastUpdatedAtTime": false }, { "name": "test4", "lastUpdatedAtTime": true } ] } const validate = ajv.compile(schema); console.log(validate(data)); console.log(validate.errors);