Add support for project-wide JSLint config.

Related to issues adobe#3269, adobe#4210.
Based on the discussion and suggestions in adobe#3310.

If a project has a .jslint.json in its root, it gets loaded and passed to each
JSLint run within the project. The configuration file gets reloaded each time
it is saved or refreshed.

src/extensions/default/JSLint/main.js

@@ -42,8 +42,10 @@ define(function (require, exports, module) {
         DocumentManager         = brackets.getModule("document/DocumentManager"),
         EditorManager           = brackets.getModule("editor/EditorManager"),
         LanguageManager         = brackets.getModule("language/LanguageManager"),
+        NativeFileSystem        = brackets.getModule("file/NativeFileSystem").NativeFileSystem,
         PreferencesManager      = brackets.getModule("preferences/PreferencesManager"),
         PerfUtils               = brackets.getModule("utils/PerfUtils"),
+        ProjectManager          = brackets.getModule("project/ProjectManager"),
         Strings                 = brackets.getModule("strings"),
         StringUtils             = brackets.getModule("utils/StringUtils"),
         AppInit                 = brackets.getModule("utils/AppInit"),
@@ -96,7 +98,19 @@ define(function (require, exports, module) {
      * @type {boolean}
      */
     var _gotoEnabled = false;
-
+
+    /**
+     * @private
+     * @type {string}
+     */
+    var _configFileName = ".jslint.json";
+
+    /**
+     * @private
+     * @type {object}
+     */
+    var _jsLintConfig = null;
+
     /**
      * Enable or disable the "Go to First JSLint Error" command
      * @param {boolean} gotoEnabled Whether it is enabled.
@@ -105,6 +119,54 @@ define(function (require, exports, module) {
         CommandManager.get(GOTO_FIRST_ERROR).setEnabled(gotoEnabled);
         _gotoEnabled = gotoEnabled;
     }
+
+    /**
+     * Load project-wide JSLint configuration.
+     *
+     * Brackets JSLint configuration should be in JSON format, with all the
+     * JSLint options specified according to JSLint documentation.
+     * 
+     * JSLint project file should be located at <Project Root>/.jslint.json . It
+     * is loaded each time project is changed or the configuration file is
+     * modified.
+     * 
+     * @return Promise to return JSLint configuration object.
+     *
+     * @see <a href="http://www.jslint.com/lint.html#options">JSLint option
+     * reference</a>.
+     */
+    function _loadProjectConfig() {
+
+        var projectRootEntry = ProjectManager.getProjectRoot(),
+            result = new $.Deferred(),
+            config;
+
+        projectRootEntry.getFile(_configFileName,
+                { create: false },
+                function (configFileEntry) {
+                var reader = new NativeFileSystem.FileReader();
+                configFileEntry.file(function (file) {
+                    reader.onload = function (event) {
+                        try {
+                            config = JSON.parse(event.target.result);
+                            result.resolve(config);
+                        } catch (e) {
+                            result.reject(e);
+                        }
+                    };
+                    reader.onerror = function (event) {
+                        result.reject(event.target.error);
+                    };
+                    reader.readAsText(file);
+                });
+            },
+            function (err) {
+                result.reject(err);
+            });
+
+        return result.promise();
+
+    }
 
     /**
      * Run JSLint on the current document. Reports results to the main UI. Displays
@@ -133,7 +195,7 @@ define(function (require, exports, module) {
             }
             text = arr.join("\n");
 
-            var result = JSLINT(text, null);
+            var result = JSLINT(text, _jsLintConfig);
 
             PerfUtils.addMeasurement(perfTimerLint);
             perfTimerDOM = PerfUtils.markStart("JSLint DOM:\t" + (!currentDoc || currentDoc.file.fullPath));
@@ -199,9 +261,9 @@ define(function (require, exports, module) {
             setGotoEnabled(false);
         }
     }
-    
+
     /**
-     * Update DocumentManager listeners.
+     * Update DocumentManager and ProjectManager listeners.
      */
     function updateListeners() {
         if (_enabled) {
@@ -211,12 +273,34 @@ define(function (require, exports, module) {
                     run();
                 })
                 .on("documentSaved.jslint documentRefreshed.jslint", function (event, document) {
+                    // if this project's JSLint config has been updated, reload
+                    if (document.file.fullPath ===
+                                ProjectManager.getProjectRoot().fullPath + _configFileName) {
+                        _loadProjectConfig()
+                            .done(function (config) {
+                                _jsLintConfig = config;
+                            })
+                            .fail(function () {
+                                _jsLintConfig = null;
+                            });
+                    }
                     if (document === DocumentManager.getCurrentDocument()) {
                         run();
                     }
                 });
+            $(ProjectManager)
+                .on("projectOpen.jslint", function () {
+                    _loadProjectConfig()
+                        .done(function (config) {
+                            _jsLintConfig = config;
+                        })
+                        .fail(function () {
+                            _jsLintConfig = null;
+                        });
+                });
         } else {
             $(DocumentManager).off(".jslint");
+            $(ProjectManager).off(".jslint");
         }
     }