fix(LogCollector): the log level used

lib/LogCollector.js

@@ -67,10 +67,9 @@ function LogCollector(logStorage, options) {
     this.maxEntryLength = options && options.maxEntryLength ? options.maxEntryLength : 10000;
     // Bind the log method for each level to the corresponding method name
     // in order to implement "global log transport" object.
-    Object.keys(Logger.levels).forEach(
+    Object.values(Logger.levels).forEach(
     function (logLevel) {
-        var methodName = Logger.levels[logLevel];
-        this[methodName] = function () {
+        this[logLevel] = function () {
             this._log.apply(this, arguments);
         }.bind(this, logLevel);
     }.bind(this));
@@ -141,12 +140,19 @@ logLevel /* timestamp, arg2, arg3, arg4... */) {
     var msg = '';
     for (var i = 1, len = arguments.length; i < len; i++) {
         var arg = arguments[i];
-        // objects logged on error level are always converted to JSON
-        if ((this.stringifyObjects || logLevel === Logger.levels.ERROR) &&
-            typeof arg === 'object') {
-            arg = this.stringify(arg);
+
+        if (this.stringifyObjects && typeof arg === 'object') {
+        // NOTE: We were trying to stringify all error logs before but because of a bug that we were getting the keys
+        // of the log levels which are all with upper case and comparing it with the keys which are all lower case we
+        // were never actually strinfying the error logs. That's why I've removed the check for error logs here.
+        // NOTE: The non-enumerable properties of the objects wouldn't be included in the string after JSON.strigify.
+        // For example Error instance will be translated to '{}'. So I think we have to eventually do something better
+        // for parsing the arguments. But since this option for strigify is part of the public interface and I think
+        // it could be useful in some cases I will it for now.
+            msg += this.stringify(arg);
+        } else {
+            msg += arg;
         }
-        msg += arg;
         if (i !== len - 1) {
             msg += ' ';
         }