instanceOf - API reference

API reference › @evolu/common › Type › instanceOf

function instanceOf<Constructor>(
  constructor: ValidateInstanceConstructor<Constructor>,
): InstanceOfType<Constructor>;

Defined in: packages/common/src/Type.ts:3270

Instance Type for one constructor.

Membership uses the intrinsic prototype chain, so subclasses are accepted, equivalent constructors from other realms are rejected, and custom Symbol.hasInstance implementations are ignored.

Use object instead when only the structure matters.

Example

import { assertFalse, assertTrue, instanceOf } from "@evolu/common";

class User {
  readonly name: string;

  constructor(name: string) {
    this.name = name;
  }
}

const UserInstance = instanceOf(User);

assertTrue(UserInstance.is(new User("Ada")));
assertFalse(UserInstance.is({ name: "Ada" }));