expect/lib/functionThrows.js

Write better assertions

'use strict';

exports.__esModule = true;

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { 'default': obj }; }

var _isRegexp = require('is-regexp');

var _isRegexp2 = _interopRequireDefault(_isRegexp);

var _isFunction = require('./isFunction');

var _isFunction2 = _interopRequireDefault(_isFunction);

/**
 * Returns true if the given function throws the given value
 * when invoked. The value may be:
 *
 * - undefined, to merely assert there was a throw
 * - a constructor function, for comparing using instanceof
 * - a regular expression, to compare with the error message
 * - a string, to find in the error message
 */
function functionThrows(fn, context, args, value) {
  try {
    fn.apply(context, args);
  } catch (error) {
    if (value == null) return true;

    if (_isFunction2['default'](value) && error instanceof value) return true;

    var message = error.message || error;

    if (typeof message === 'string') {
      if (_isRegexp2['default'](value) && value.test(error.message)) return true;

      if (typeof value === 'string' && message.indexOf(value) !== -1) return true;
    }
  }

  return false;
}

exports['default'] = functionThrows;
module.exports = exports['default'];