smikhalevski/doubter

🤔 Runtime validation and transformation library.

Hi there 👋

doubter's Issues

How to perform an async validation? it's missing from docs

The README did mention that it's possible to create async validations but it doesn't include an example, neither the tests include one.

I tried to use check method

import * as d from 'doubter';

async function isOdd(value: number): Promise<boolean> {
  return value % 2 === 0;
}

const oddNumber = d.number()
  .coerce()
  .check(async (value) => {
    if (await isOdd(value)) {
      return null;
    }
    return {
      code: 'odd_number',
      message: 'Number must be odd',
    } satisfies d.Issue;
  });

await oddNumber.parseAsync(4);

⚠️ Typescript error

error TS2345: Argument of type '(value: number) => Promise<{ code: string; message: string; } | null>' is not assignable to parameter of type 'CheckCallback'.
Type 'Promise<{ code: string; message: string; } | null>' is not assignable to type 'void | Issue | Issue[] | null | undefined'.

💥 Runtime error

ValidationError: [
  {}
]
    at new ValidationError (/Users/developer/Projects/express-mssql-example/node_modules/.pnpm/[email protected]/node_modules/doubter/lib/index.js:370:28) {
  issues: [
    Promise {
      undefined,
      [Symbol(async_id_symbol)]: 909,
      [Symbol(trigger_async_id_symbol)]: 6
    }
  ]
}

Or using refine method

import * as d from 'doubter';

async function isOdd(value: number): Promise<boolean> {
  return value % 2 === 0;
}

const oddNumber = d.number()
  .coerce()
  .refine(isOdd);
  
await oddNumber.parseAsync(3)

⚠️ Typescript error

error TS2769: No overload matches this call.
Overload 1 of 2, '(cb: (output: number, options: Readonly) => output is number, options?: RefineOptions | Message | undefined): Shape', gave the following error.
  Argument of type '(value: number) => Promise' is not assignable to parameter of type '(output: number, options: Readonly) => output is number'.
    Signature '(value: number): Promise' must be a type predicate.
Overload 2 of 2, '(cb: (output: number, options: Readonly) => boolean, options?: RefineOptions | Message | undefined): NumberShape', gave the following error.
  Argument of type '(value: number) => Promise' is not assignable to parameter of type '(output: number, options: Readonly) => boolean'.
    Type 'Promise' is not assignable to type 'boolean'.

🤷 no error but it always pass

Promise {
  ,
  [Symbol(async_id_symbol)]: 1254,
  [Symbol(trigger_async_id_symbol)]: 1253
}
3

Doubter version: 2.1.0
Node.js version: 20.3.1

PS: my actual use case is that I want to check whether a value exist in the DB