Someone to check & test my code, Toolbox bug suspiction

Add-ons Development
1

I have found strange behaviour of Content Toolbox tool. I have no explanation for this behaviour, so I look for somebody who can test it and possibly find a bug.

Using FF version 48.0b10, jquery min injected to Content Scripts. Another content script is named inspector.js

I add my addon to addon Debugger and then I open mozilla page as an example page.

Then I press ctrl+alt+shift+I to run Browser Content, I search for inspector.js.

First I add breakpoint on line 32 to test the for loop, then I add breakpoint on line 39 to test if the div will appear near the area where I clicked.

The inspector.js (all rights reserved by h4ever) follows:

document.body.style.border = "80px solid green";

var maxLevel = 20;
var elements = { length: 0, collection:[] };

// // Handle messages from the add-on background page:
chrome.runtime.onMessage.addListener(
  function (package){
    if (package.command !== "inspector")
      return false;
    console.log("Recieved message:");
    
    document.addEventListener('click', function(e)
    {  
    getParent(e.target);
    var node1 = $("#test_styles");
    var node2 = $("#test_panel");
    if ( node1.length ) node1.remove();
    if ( node2.length ) node2.remove();

    var ClientW = jQuery(window).width();
    var ClientH = jQuery(window).height();  
    var y = (e.clientY < ClientH / 6 )?e.clientY+80:
         (e.clientY > ClientH - ClientH / 6 )?e.clientY-80:e.clientY;
    var x = (e.clientX < ClientW / 4 )?e.clientX+80:
         (e.clientX > ClientW - ClientW / 4 )?e.clientX-80:e.clientX;  	    

    $("html > head").append("<style id=test_styles>div#test_panel { position: absolute; border-radius: 3px; font-family:'Arial Black'; font-size:13px; }</style>\n\r");      
    $("body").append("<div id=test_panel></div>");
    $('div#test_panel').append("<ul>");
    var level = elements.length;
    for (var level = elements.length; 
        level>1 ; 
        level--)
      {
      $('div#test_panel ul').append("<li>" + elements.collection[level].tag + "</li>\r\n");
      }    
    });
    $('#test_panel').css({ left: x, top: y })  
  
  }
  );

function getParent(element, level = 0 ){  

  level++;
  elements.collection[level] = { tag: "", attrs: {} }
  elements.collection[level].tag = element.nodeName; 
  
  console.log(element.parentElement);
  
  attrs = element.attributes;  
  elements.collection[level].attrs = { vals: [] , names: [] };
  for (var i = 0; i < attrs.length; i++)
    {
      elements.collection[level].attrs.names.push(attrs[i].name);
      elements.collection[level].attrs.vals.push(attrs[i].value);
    } 
  
  if (null === element.parentElement || level > maxLevel)
    {
    elements.length = level;
    return false;
    }
  else
    getParent(element.parentElement, level);
  
  return true;  
}

The results:

  1. Test of for loop.
    The for loop is performed and finished, but this is reapeated 3 times which is not normal. Why?
  2. Test of the line 39. The variables x, y and level are not accessible in this context. Why? Therefor the function .css fails.

Can you explain this behaviour?
Is the bug on my site or is it Firefox - Toolbox problem?

2

I took the freedom to run your code through a JS beautifier to fix the seemingly random indents:

document.body.style.border = "80px solid green";

var maxLevel = 20;
var elements = {
    length: 0,
    collection: []
};

// // Handle messages from the add-on background page:
chrome.runtime.onMessage.addListener(
    function(package) {
        if (package.command !== "inspector")
            return false;
        console.log("Recieved message:");

        document.addEventListener('click', function(e) {
            getParent(e.target);
            var node1 = $("#test_styles");
            var node2 = $("#test_panel");
            if (node1.length) node1.remove();
            if (node2.length) node2.remove();

            var ClientW = jQuery(window).width();
            var ClientH = jQuery(window).height();
            var y = (e.clientY < ClientH / 6) ? e.clientY + 80 :
                (e.clientY > ClientH - ClientH / 6) ? e.clientY - 80 : e.clientY;
            var x = (e.clientX < ClientW / 4) ? e.clientX + 80 :
                (e.clientX > ClientW - ClientW / 4) ? e.clientX - 80 : e.clientX;

            $("html > head").append("<style id=test_styles>div#test_panel { position: absolute; border-radius: 3px; font-family:'Arial Black'; font-size:13px; }</style>\n\r");
            $("body").append("<div id=test_panel></div>");
            $('div#test_panel').append("<ul>");
            var level = elements.length;
            for (var level = elements.length; level > 1; level--) {
                $('div#test_panel ul').append("<li>" + elements.collection[level].tag + "</li>\r\n");
            }
        });
        $('#test_panel').css({
            left: x,
            top: y
        })

    }
);

function getParent(element, level = 0) {

    level++;
    elements.collection[level] = {
        tag: "",
        attrs: {}
    }
    elements.collection[level].tag = element.nodeName;

    console.log(element.parentElement);

    attrs = element.attributes;
    elements.collection[level].attrs = {
        vals: [],
        names: []
    };
    for (var i = 0; i < attrs.length; i++) {
        elements.collection[level].attrs.names.push(attrs[i].name);
        elements.collection[level].attrs.vals.push(attrs[i].value);
    }

    if (null === element.parentElement || level > maxLevel) {
        elements.length = level;
        return false;
    } else
        getParent(element.parentElement, level);

    return true;
}

First to why x and y are not defined: the $.css is run after the listener was added, and not at the end of the listener as should be quite clear from the version of the code I posted above.

Further you don’t have to set var level = elements.length; before the for loop, the initialization statement will do that.

3

Thank you. I thought it is some harder problem expecting days of delay. I know the declaration of level was redundant.

BTW: Did you noticed, you changed order of the listed items ?
(var i = 0; i < attrs.length; i++)
vs
(var level = elements.length; level>1 ; level–)

4

I had not noticed that, probably a setting within the transformer I used. I guess it’s to avoid reading .length every iteration step, as it can not know that this is a static property and not an actual array length property.

5

I do not understand your last reply. I have initiated the level to = elements.lenght so there is no change to be a length detected in every iteration.

6

Yes, but doing it this way saves even a variable. I’m not sure it’s worth it, it’s just an “optimization” the tool used seemed to have applied. There’s not much more to it.

7

True, the first part of the for command could be omitted completely.