ts-type-check

Check json value based of Typescript type in string

Supported Data Type

• string
• number
• boolean
• Date
• object (with required / optional fields)
• array
• unions
• intersections
• unit types*

*: Unit types are the literal value of primitive types, e.g. true | false | 'str' | 1

Example

import { checkTsType } from 'ts-type-check'

checkTsType('string', 'Alice');
// no error


checkTsType('{ UserId: string }', { UserId: 'Alice' });
// no error
checkTsType('{ UserId: string }', { UserId: 'Alice', Foo: 'bar' }, 'fail');
// throw exception complaining extra field `Foo`

More advanced type using nested object, |, and & are also supported.

import { checkTsType } from 'ts-type-check'


checkTsType(`'y' | 'n'`, 'n');
// no error
checkTsType(`1 | 2`, 1);
// no error
checkTsType(`'y' | 'n'`, 'foo');
// throw exception complaining wrong string value
checkTsType(`1 | 2`, 3);
// throw exception complaining wrong number value

checkTsType(`{
    UserId: string,
    Contact: {
      Method: 'telegram'
    } & ({ UserId: string } | { Tel: string }) | {
      Method: 'Email',
      Email: string
    }
  }`,{
    UserId: 'Alice',
    Contact: {
      Method: 'telegram',
      UserId: 'alice',
    },
  });
// no error
checkTsType(`{
    UserId: string,
    Contact: {
      Method: 'telegram'
    } & ({ UserId: string } | { Tel: string }) | {
      Method: 'Email',
      Email: string
    }
  }`,{
    UserId: 'Alice',
    Contact: {
      Method: 'Email',
      Email_: 'alice@domain.com',
    },
  });
// throw exception complaining missing field 'Email' (if the field is given, then will complain extra field 'Email_')