bitcoinjs-lib/src/types.js

module.exports = function enforce(type, value) {
  switch (type) {
    case 'Array': {
      if (Array.isArray(value)) return
      break
    }

    case 'Boolean': {
      if (typeof value === 'boolean') return
      break
    }

    case 'Buffer': {
      if (Buffer.isBuffer(value)) return
      break
    }

    case 'Number': {
      if (typeof value === 'number') return
      break
    }

    case 'String': {
      if (typeof value === 'string') return
      break
    }

    default: {
      if (value.constructor.toString().match(/function (.*?)\(/)[1] === type.name) return
    }
  }

  throw new TypeError('Expected ' + (type.name || type) + ', got ' + value)
}