fix($log): avoid console.log.apply calls in IE

In IE window.console.log and friends are functions that don't have apply or call fns.

For this reason we have to treat them specially and do our best to log at least
something when running in this browser.

Closes #805

Author: IgorMinar

Diff for: src/service/log.js

@@ -93,19 +93,23 @@ function $LogProvider(){
     }
 
     function consoleLog(type) {
-      var console = $window.console || {};
-      var logFn = console[type] || console.log || noop;
+      var console = $window.console || {},
+          logFn = console[type] || console.log || noop;
+
       if (logFn.apply) {
         return function() {
           var args = [];
-          forEach(arguments, function(arg){
+          forEach(arguments, function(arg) {
             args.push(formatError(arg));
           });
           return logFn.apply(console, args);
         };
-      } else {
-        // we are IE, in which case there is nothing we can do
-        return logFn;
+      }
+
+      // we are IE which either doesn't have window.console => this is noop and we do nothing,
+      // or we are IE where console.log doesn't have apply so we log at least first 2 args
+      return function(arg1, arg2) {
+        logFn(arg1, arg2);
       }
     }
   }];

Diff for: test/service/logSpec.js

@@ -1,17 +1,18 @@
 'use strict';
 
 describe('$log', function() {
-  var $window;
-  var logger;
+  var $window, logger, log, warn, info, error;
+
 
-  function log() { logger+= 'log;'; }
-  function warn() { logger+= 'warn;'; }
-  function info() { logger+= 'info;'; }
-  function error() { logger+= 'error;'; }
 
   beforeEach(module(function($provide){
     $window = {};
     logger = '';
+    log = function() { logger+= 'log;'; };
+    warn = function() { logger+= 'warn;'; };
+    info = function() { logger+= 'info;'; };
+    error = function() { logger+= 'error;'; };
+
     $provide.provider('$log', $LogProvider);
     $provide.value('$exceptionHandler', angular.mock.rethrow);
     $provide.value('$window', $window);
@@ -58,6 +59,28 @@ describe('$log', function() {
   ));
 
 
+  it("should work in IE where console.error doesn't have apply method", inject(
+      function() {
+        log.apply = log.call =
+            warn.apply = warn.call =
+            info.apply = info.call =
+            error.apply = error.call = null;
+
+        $window.console = {log: log,
+                           warn: warn,
+                           info: info,
+                           error: error};
+      },
+      function($log) {
+        $log.log.apply($log);
+        $log.warn.apply($log);
+        $log.info.apply($log);
+        $log.error.apply($log);
+        expect(logger).toEqual('log;warn;info;error;');
+      })
+  );
+
+
   describe('$log.error', function() {
     var e, $log, errorArgs;