esnextbin sketch

daysOfTheWeek.md

This a simple gist to demostrate how to use date-fns to check the days of the week. Also, using invarant to throw errors.

index.js

import format from 'date-fns/format';
import invariant from 'invariant';

// Throw a error if it's not the right Day of the week.
function isRightDay(date, actualDay, errorMsg) {
  const dayVal = format(date, 'dddd');
  invariant(dayVal === actualDay, errorMsg);
};

// Quick example of how to execute the function
// For further options check date-fns module
isRightDay(new Date(),'Wednesday', 'Make sure the day is wed' );

package.json

{
  "name": "esnextbin-sketch",
  "version": "0.0.0",
  "dependencies": {
    "invariant": "2.2.1",
    "date-fns": "1.3.0"
  }
}

transpiled.js

'use strict';

var _format = require('date-fns/format');

var _format2 = _interopRequireDefault(_format);

var _invariant = require('invariant');

var _invariant2 = _interopRequireDefault(_invariant);

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

// Throw a error if it's not the right Day of the week.
function isRightDay(date, actualDay, errorMsg) {
  var dayVal = (0, _format2.default)(date, 'dddd');
  (0, _invariant2.default)(dayVal === actualDay, errorMsg);
};

// Quick example of how to execute the function
// For further options check date-fns module
isRightDay(new Date(), 'Wednesday', 'Make sure the day is wed');