What version of Ajv are you using? Does the issue happen if you use the latest version?
8.11.2 (latest as of this writing)
Ajv options object
import Ajv, { JTDSchemaType } from "ajv/dist/jtd";
const ajv = new Ajv();JTD Schema
type MyType = {
referenced: number;
stringProp: string;
};
const schema: JTDSchemaType<MyType, { num: number }> = {
definitions: {
num: { type: "int32" }
},
properties: {
referenced: { ref: "num" },
stringProp: { type: "string" }
}
} as const;Sample data
Your code
const validate = ajv.compile(schema);
if (validate(data)) {
const revealType: never = data;
const stringProp: string = data.stringProp;
console.log(stringProp);
}https://replit.com/@ento/IntrepidIndolentOutput#index.ts
^strictNullChecks is enabled in tsconfig.json
"strictNullChecks": true,
Validation result, data AFTER validation, error messages
TypeScript's typecheck errors:
// const revealType
Type '{ referenced: number; stringProp: unknown; } & {}' is not assignable to type 'never'.
// const stringProp
Type 'unknown' is not assignable to type 'string'.
What results did you expect?
The type of stringProp to be string after being narrowed by validate(data)
Are you going to resolve the issue?
My current workaround is to hold the definition in a const and use it to compose the schema object. (The actual code is a bit more complex than this.)
const numSchema = { type: "int32" } as const;
const schema: JTDSchemaType<MyType> = {
properties: {
referenced: numSchema,
stringProp: { type: "string" }
}
} as const; 
What version of Ajv are you using? Does the issue happen if you use the latest version?
8.11.2 (latest as of this writing)
Ajv options object
JTD Schema
Sample data
Your code
https://replit.com/@ento/IntrepidIndolentOutput#index.ts
^
strictNullChecksis enabled intsconfig.jsonValidation result, data AFTER validation, error messages
TypeScript's typecheck errors:
What results did you expect?
The type of
stringPropto bestringafter being narrowed byvalidate(data)Are you going to resolve the issue?
My current workaround is to hold the definition in a const and use it to compose the schema object. (The actual code is a bit more complex than this.)