rogozhin/cast-with-schema

Casting JS objects to correct types using JSON schemas

cast-with-schema

The way to cast data to types specified with JSON schema.

Arguments

• source (object) - Source object to be casted.
• schema (object) - JSON schema containing types definitions.
• options (object)
  • allowNaN — Whether or not to return NaN for non-parseable numbers. The default is false which will cast NaN to 0.

Example

May be used for query params casting:

const qs = require('qs');
const castWithSchema = require('cast-with-schema');

const schema = {
  type: "object",
  properties: {
    param1: {
      type: 'string',
    },
    param2: {
      type: 'integer',
    },
    param3: {
      type: 'number',
    },
    param4: {
      type: 'boolean',
    },
  }
};

const query = 'param1=value&param2=777&param3=7.77&param4=false';
const parsed = qs.parse(query);
const casted = castWithSchema(query, schema);

/*
  `casted` is now:
  {
    param1: 'value',
    param2: 777,
    param3: 7.77,
    param4: false,
  }
*/

Supports null if schema is either:

type: ['..', 'null']

or

anyOf: [
  { type: '..' },
  { type: 'null' }
]

See also

Check out tinsypec for more smart JSON schema use cases.