ajv_json_schema_validation_with_typescript_interfaces.ts

1import Ajv, {JSONSchemaType} from "ajv"
2
3const ajv = new Ajv()
4
5interface MyData {
6  foo: number
7  bar?: string
8}
9
10const schema: JSONSchemaType<MyData> = {
11  type: "object",
12  properties: {
13    foo: {type: "integer"},
14    bar: {type: "string", nullable: true}
15  },
16  required: ["foo"],
17  additionalProperties: false
18}
19
20const validate = ajv.compile(schema)
21
22const data = {
23  foo: 1,
24  bar: "abc"
25}
26
27if (validate(data)) {
28  // data is MyData here
29  console.log(data.foo)
30} else {
31  console.log(validate.errors)
32}