Temporary coerce

[olivermaldonado]

Is there a way to temporarily transform or coerce an input, run it through some verifications, and return the original input?

For example, create a schema that accepts a number, that passes some number-specific validations, but that can also accept a string representation of the number, and pass it through the same validations, coerced as a number. Then output the original input value, in this example either a string or a number.

Right now the coerce function will irrevocably change the type.

[fabian-hiller]

Something like that could work. Check it out in our playground.

const Schema = v.union(
  [v.string([v.regex(/^-?\d+(?:\.\d+)?$/)]), v.number()],
  [
    v.custom((input) => Number(input) >= 0, 'Number is too small'),
    v.custom((input) => Number(input) <= 100, 'Number is too big'),
  ]
);

[olivermaldonado]

Yes. Using custom validators will work. I was trying to use the predefined validators included in the library.

I was trying to make a function that returns a predefined schema that would accept an array of unknown validators to check against a number type as a last step, but that would also accept (and return) string representations.

By only using custom validators it will work. Thanks.