Feedback on Handling Default Values in Nested Structures with TypeBox

[anuj-kr-jha]

Hello everyone,

I've been working on a project using the @sinclair/typebox library to define and validate data structures in Node.js. My main goal is to ensure that all objects, including nested ones, are filled with default values and correctly handle type conversions.

Here's the approach I've developed:

import { log } from 'node:console';
import { Type } from '@sinclair/typebox';
import { TypeCompiler } from '@sinclair/typebox/compiler';
import { Value } from '@sinclair/typebox/value';

const T = Type.Object(
  {
    userName: Type.Optional(Type.String()),
    loginAt: Type.Optional(Type.Number({ default: Date.now() })),
    settings: Type.Object(
      {
        language: Type.Optional(Type.Number({ default: 1 }))
      },
      { default: {} }
    ),
    roles: Type.Array(Type.String(), { default: ['user'] }),
    status: Type.Enum({ one: 1, two: 2, three: 3 }, { default: 1 })
  },
  { additionalProperties: false }
);

const C = TypeCompiler.Compile(T); // this to be done once and reused for all checks

const val = {
  userName: 123,
};

let V = Value.Default(T, Value.Clone(val)); // fill missing val
V = Value.Convert(T, V); // type conversion
const R = C.Check(V); // check error
const E1 = R ? C.Errors(V).First() : null; // 1st error

log({
  value: V,
  error: E1
});

i t results in

{
  value: {
    userName: '123',
    settings: { language: 1 },
    loginAt: 1713683973839,
    roles: [ 'user' ],
    status: 1
  },
  error: undefined
}

this is serving the purpose for me.

I just wanted to ask whether this approach is good or I can further optimize it.
thanks