Generate new random value if value is in array

Question

I have a situation where I'm using protractor to click a random link on the page. (There are a lot). I have an array of links that I don't want to click, so I want to know when my random link is in that array and generate a new random link.

Here's my working code to click a random link on the page

var noClickArray = ['link2', 'link3']; // array much bigger than this
var parent = this;

function() {
  var links = element.all(by.css('.links'));
  return links.count().then(function(count) {
    var randomLink = links.get(Math.floor(Math.random() * count));
    randomLink.getText().then(function(text) {
      parent.selectedLink = text; // used in a different function
      var containsLink = _.includes(noClickArray, text);
    });
    return randomLink.click();
  });
}

I'm using lodash to find if the randomLink text is in noClickArray but I don't know how to keep generating random values until the value does not exist in the array. How can I do this?

Answer 1

I think you are overcomplicating the problem. I would just filter out links you don't want to click using filter() beforehand:

function() {
  var links = element.all(by.css('.links'));
  links = links.filter(function (link) {
      return link.getText().then(function(text) {
          return !_.includes(noClickArray, text);
      });
  });

  return links.count().then(function(count) {
    var randomLink = links.get(Math.floor(Math.random() * count));
    return randomLink.click();
  });
}

Answer 2

You could simply use a recursive call until you get a non black listed link. This way, you will avoid the cost of getting the text for all the links:

function() {
  return element.all(by.css('.links')).then(function clickRandom(links) {

    // remove a random link from the array of links
    var link = links.splice(Math.floor(Math.random() * links.length), 1)[0];

    return link && link.getText().then(function(text) {
      if(noClickArray.indexOf(text) === -1) {  // if not black listed
        return link.click();  // click link
      }
      return clickRandom(links); // try again
    });

  });
}