function tester(idList, test, description) {
    "use strict";

    var color = "";
    var index = 0;
    var li = document.createElement("li");
    var list = document.getElementById(idList);
    var result = "";

    index = list.childElementCount + 1;
    if (test) {
        color = "green";
        result = "<b>" + index + ". </b>" + description;

    } else {
        color = "red";
        description = "<s>" + description + "</s>";
        result = "<b>" + index + ". </b>" + description;
    }
    li.style.margin = "8px";
    li.style.padding = "2px";
    li.style.color = color;
    li.innerHTML = result;
    list.insertBefore(li, list.childNodes[0]);
}

@@ -13,16 +13,8 @@
 ter(
-idList, 
 test
@@ -26,16 +26,24 @@
 cription
+, idList
 ) %7B%0A    
@@ -53,24 +53,59 @@
 e strict%22;%0A%0A
+    idList = idList %7C%7C 'testList';%0A
     var colo
@@ -328,65 +328,8 @@
 en%22;
-%0A        result = %22%3Cb%3E%22 + index + %22. %3C/b%3E%22 + description;
 %0A%0A  
@@ -418,65 +418,8 @@
 %3E%22;%0A
-        result = %22%3Cb%3E%22 + index + %22. %3C/b%3E%22 + description;%0A
     
@@ -515,75 +515,108 @@
     
-li.innerHTML = result;%0A    list.insertBefore(li, list.childNodes%5B0%5D
+result = %22%3Cb%3E%5B%22 + index + %22%5D %3C/b%3E%22 + description;%0A    li.innerHTML = result;%0A    list.appendChild(li
 );%0A%7D

Update tester-function.js