dealertrack-modify_string.js

// Tested on Node REPL v4.0.0

"use strict";

const tests = {
  case1: {
    name: 'Case 1',
    string: 'Automotive',
    expect: 'A6e'
  },
  case2: {
    name: 'Case 2',
    string: 'Transforming the way the world buys, sells and owns cars.',
    expect: 'T8g t1e w1y t1e w3d b2s, s2s a1d o2s c2s.'
  },
  case3: {
    name: 'Case 3',
    string: 'Dealertrack is the leading provider of digital solutions to the automotive retail industry. ' +
            'Whether you’re a dealer, a lender, a manufacturer, or a state agency, our integrated and ' +
            'intuitive approach to products and services makes your workflows more efficient, transparent, ' +
            'and profitable. From our pioneering Digital Retailing tools—bridging the gap between the ' +
            'online and in-store experience—to our lender network (the largest in North America) ' +
            'Dealertrack is the only company helping enable the transformation of auto retailing.',
    expect: 'D6k i0s t1e l5g p6r o0f d4l s6s t0o t1e a6e r4l i6y. ' +
            'W3r y1u’r0e a d3r, a l3r, a m8r, o0r a s2e a4y, o1r i6d a1d ' +
            'i5e a5h t0o p6s a1d s5s m3s y2r w6s m2e e5t, t6t, ' +
            'a1d p8e. F2m o1r p5g D4l R6g t2s—b5g t1e g1p b3n t1e ' +
            'o3e a1d i0n-s3e e7e—t0o o1r l3r n5k (t1e l5t i0n N3h A5a) ' +
            'D6k i0s t1e o2y c5y h5g e4e t1e t9n o0f a2o r6g.'
  },
  case4: {
    name: 'Case 4',
    string: 'Lake Success, N.Y., March 23, 2016 – Helping to further advance the adoption of digital ' +
            'technologies among automotive finance lenders and dealers, Dealertrack® today announced ' +
            'that Ally Financial is now broadly available for eContracting through the Dealertrack platform.',
    expect: 'L2e S4s, N.Y., M3h 23, 2016 – H5g t0o f5r a5e t1e a5n o0f d4l ' +
            't8s a3g a6e f4e l4s a1d d4s, D6k® t3y a5d ' +
            't2t A1y F4l i0s n1w b5y a5e f1r e8g t5h t1e D6k p6m.'
  },
  case5: {
    name: 'Case 5',
    string: '----12svd3f%+=floo r~59nrtx.456yn',
    expect: '----12s1d3f%+=f2o r~59n2x.456y0n'
  }
};

function testModifyString (testObj) {
  let result = modifyString(testObj.string);
  
  if (result === testObj.expect) {
    console.log('(*^_^*) Test ' + testObj.name + ', Passing.');
  } else {
    console.warn(
      '[!] Test ' + testObj.name + ', Failing. Expected: "' +
      result + '", to be: "' + testObj.expect + '"'
    );
  }
}

testModifyString(tests.case1);
testModifyString(tests.case2);
testModifyString(tests.case3);
testModifyString(tests.case4);
testModifyString(tests.case5);

function modifyString (string) {
  const regexNonAlpha = /([^A-z])/;
  const arr = string.split(regexNonAlpha).map((str) => {
    let modifiedStr;
    
    if (str.length >= 2) {
      let uniqueCount = 0;
      let middleChars = str.slice(1, -1).split('').sort();
      
      for (let i = 0; i < middleChars.length; i++) {
        if (middleChars[i] !== middleChars[i - 1]) {
          uniqueCount += 1;
        }
      }
      
      modifiedStr = str[0] + uniqueCount + str[str.length - 1];
    } else {
      modifiedStr = str;
    }
    
    return modifiedStr;
  });
  
  return arr.join('');
}