legex (lesser regex)

Regular Expression is too difficult to me, so I am looking for a descriptive way to write validators and combining validators by logic gate to generate new validator. And after I finished this library, I found that I can write 'native' Regular Expression now...

Installation

npm i legex --save

Usage

const legex = require('legex');
// bundled file at 'legex/dist/' for browser

const c = legex.C;
const v = legex.V;

// Construction of Email Validation:

// Condition1 before '@':
const beforeAtType1 = c.And(
  v.StartWithNon('<>()[]\\.,;:@ '), // not start with '<>()[]\\.,;:@ '
  v.HasN(1, '@'), // has one '@''
  v.BeforeNth(
    1, '@', // before the first '@'
    v.Exclude('<>()[]\\,;:@ ') // do not contain '<>()[]\\,;:@ '
  )
);

// Condition2 before '@':
const beforeAtType2 = v.BeforeNth(
  1, '@', // before the first '@'
  v.QuoteBy(
    '"', '"',
    v.Anything()
  )
);

// Combination of Conditions before '@':
const beforeAt = c.Or(beforeAtType1, beforeAtType2);

// Condition1 after '@':
const afterAtType1 = v.AfterNth(
  1, '@', // after the first '@'
  v.QuoteBy(
    '[', ']',
    v.IsIP() // format of IP
  )
);

// A Validator for checking does the string contain at least 2 alphabets (and alphabets only)
const alphabets = c.And(
  v.IsAlphabet(), // alphabets
  v.LenGeq(2) // more than 2(inclusive)
);

// Condition2 after '@':
const afterAtType2 = c.And(
  v.AfterNth(
    1, '@', // after the first '@'
    v.BeforeNth(
      1, '.', // before the first '.'
      v.IsWord() // is word character (a-z, A-Z, 0-9, _)
    )
  ),
  v.AfterNth(
    1, '@', // after the first '@'
    v.AfterNth(
      1, '.', // after the first '.'
      alphabets // contains at least 2 alphabets
    )
  )
);

// Combination of Conditions after '@':
const afterAt = c.Or(afterAtType1, afterAtType2);

// A full email Validator (It is not 100% correct, seems some conditions are wrong)
const email = c.And(beforeAt, afterAt);

// Tests:
console.log('Valid emails:');
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('aaa@[192.168.0.1]', email('aaa@[192.168.0.1]'));
assert('\".....\"@aaa.dds', email('\".....\"@aaa.dds'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('#!$%&\'*+-/=?^_`{}|[email protected]', email('#!$%&\'*+-/=?^_`{}|[email protected]'));

console.log('Invalid emails:');
assert('[email protected]', !email('[email protected]'));
assert('[email protected]', !email('[email protected]'));
assert('[email protected]', !email('[email protected]'));
assert('aaa@[19.23.2]', !email('aaa@[19.23.2]'));
assert('[email protected]', !email('[email protected]'));

// Email validation is common, so this library has a true validation for that XD
// https://stackoverflow.com/questions/46155/how-to-validate-an-email-address-in-javascript
console.log('Valid emails:');
assert('[email protected]', v.IsEmail().check('[email protected]'));
assert('[email protected]', v.IsEmail().check('[email protected]'));
assert('aaa@[192.168.0.1]', v.IsEmail().check('aaa@[192.168.0.1]'));
assert('\".....\"@aaa.dds', v.IsEmail().check('\".....\"@aaa.dds'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('[email protected]', email('[email protected]'));
assert('#!$%&\'*+-/=?^_`{}|[email protected]', email('#!$%&\'*+-/=?^_`{}|[email protected]'));

console.log('Invalid emails:');
assert('[email protected]', !v.IsEmail().check('[email protected]'));
assert('[email protected]', !v.IsEmail().check('[email protected]'));
assert('[email protected]', !v.IsEmail().check('[email protected]'));
assert('aaa@[19.23.2]', !v.IsEmail().check('aaa@[19.23.2]'));
assert('[email protected]', !v.IsEmail().check('[email protected]'));

// helper
function assert(description, boolean, msg) {
  console.log(description);
  if (!boolean)
    throw new Error(msg);
  else
    console.log('pass');
}

Test

Test cases not yet finish

npm test

Build

npm run build