Ticket #5398: syntax_errors.patch

loader.js

@@ -98 +98 @@
                         return true; // Boolean
                 }
                 var contents = this._getText(uri, true);
+
                 if(!contents){ return false; } // Boolean
                 this._loadedUrls[uri] = true;
                 this._loadedUrls.push(uri);
@@ -293 +294 @@
                 var ok = this._loadPath(relpath, modArg);
 
                 if((!ok)&&(!omitModuleCheck)){
-                        throw new Error("Could not load '" + moduleName + "'; last tried '" + relpath + "'");
+                        
+                        if( !this._parsingBadFile ){  // Errors pass through here twice. Only allow once 
+                        
+                                this._parsingBadFile = true;
+                                var _lastLoaded = this._loadedUrls[this._loadedUrls.length-1];
+                                var _badFile = relpath.split("/")[relpath.split("/").length-1];
+                                
+                                //              Checking if the last file attempted to load is also the last file loaded. 
+                                //              In other words, this script block only cares about syntax errors. If it 
+                                //              was a file-not-found, that error needs to skip this and pass down to the 
+                                //              'throw' below.
+                                //
+                                if(_lastLoaded.indexOf(_badFile)){ 
+                                        
+                                        //              In the event of a script error, dynamically create a script tag and 
+                                        //              load suspect script into it. The script can then be evaluated directly 
+                                        //              by the Javascript debugger and gives an accurate pointer to location of 
+                                        //              the problem, and a general description of the incorrect syntax. 
+                                        //              Yes, this even works in IE.
+                                        //
+                                        var scr = document.createElement("script");
+                                        scr.src = _lastLoaded;
+                                        document.getElementsByTagName("head")[0].appendChild(scr);
+                                        
+                                        //              Stop the thread here, and don't go through to the error throw below. 
+                                        //              It's inaccurate for syntax errors anyway. It causes a double error, 
+                                        //              and the 'throw' is first, with a misleading pointer to this script.
+                                        //
+                                        return;
+                                }
+                        }
+                        //
+                        throw new Error("Could not load '" + moduleName + "'; last tried: '" + relpath + "'");
                 }
 
                 // check that the symbol was defined