MD Settings: Adding some unit tests for <settings-main>.

chrome/browser/resources/settings/search_settings.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('settings', function() {
   /** @const {string} */
   var WRAPPER_CSS_CLASS = 'search-highlight-wrapper';
 
   /** @const {string} */
   var HIT_CSS_CLASS = 'search-highlight-hit';
@@ skipping 82 matching lines @@
       }
     }
   }
 
   /**
    * Traverses the entire DOM (including Shadow DOM), finds text nodes that
    * match the given regular expression and applies the highlight UI. It also
    * ensures that <settings-section> instances become visible if any matches
    * occurred under their subtree.
    *
-   * @param {!SearchRequest} request
+   * @param {!settings.SearchRequest} request
    * @param {!Node} root The root of the sub-tree to be searched
    * @private
    */
   function findAndHighlightMatches_(request, root) {
     var foundMatches = false;
     function doSearch(node) {
       if (node.nodeName == 'TEMPLATE' && node.hasAttribute('name') &&
           !node.if) {
         getSearchManager().queue_.addRenderTask(
             new RenderTask(request, node));
@@ skipping 46 matching lines @@
       parent = parent.nodeType == Node.DOCUMENT_FRAGMENT_NODE ?
           parent.host : parent.parentNode;
     }
     if (parent)
       parent.hidden = false;
   }
 
   /**
    * @constructor
    *
-   * @param {!SearchRequest} request
+   * @param {!settings.SearchRequest} request
    * @param {!Node} node
    */
   function Task(request, node) {
-    /** @protected {!SearchRequest} */
+    /** @protected {!settings.SearchRequest} */
     this.request = request;
 
     /** @protected {!Node} */
     this.node = node;
   }
 
   Task.prototype = {
     /**
      * @abstract
      * @return {!Promise}
      */
     exec: function() {},
   };
 
   /**
    * A task that takes a <template is="dom-if">...</template> node corresponding
    * to a setting subpage and renders it. A SearchAndHighlightTask is posted for
    * the newly rendered subtree, once rendering is done.
    * @constructor
    * @extends {Task}
    *
-   * @param {!SearchRequest} request
+   * @param {!settings.SearchRequest} request
    * @param {!Node} node
    */
   function RenderTask(request, node) {
     Task.call(this, request, node);
   }
 
   RenderTask.prototype = {
     /** @override */
     exec: function() {
       var subpageTemplate =
@@ skipping 13 matching lines @@
           resolve();
         }.bind(this));
       }.bind(this));
     },
   };
 
   /**
    * @constructor
    * @extends {Task}
    *
-   * @param {!SearchRequest} request
+   * @param {!settings.SearchRequest} request
    * @param {!Node} node
    */
   function SearchAndHighlightTask(request, node) {
     Task.call(this, request, node);
   }
 
   SearchAndHighlightTask.prototype = {
     /** @override */
     exec: function() {
       var foundMatches = findAndHighlightMatches_(this.request, this.node);
       this.request.updateMatches(foundMatches);
       return Promise.resolve();
     },
   };
 
   /**
    * @constructor
    * @extends {Task}
    *
-   * @param {!SearchRequest} request
+   * @param {!settings.SearchRequest} request
    * @param {!Node} page
    */
   function TopLevelSearchTask(request, page) {
     Task.call(this, request, page);
   }
 
   TopLevelSearchTask.prototype = {
     /** @override */
     exec: function() {
       findAndRemoveHighlights_(this.node);
@@ skipping 186 matching lines @@
     updateMatches: function(found) {
       this.foundMatches_ = this.foundMatches_ || found;
     },
 
     /** @return {boolean} Whether any matches were found. */
     didFindMatches: function() {
       return this.foundMatches_;
     },
   };
 
+  /** @interface */
+  var SearchManager = function() {};
+
+  SearchManager.prototype = {
+    /**
+     * @param {string} text The text to search for.
+     * @param {!Node} page
+     * @return {!Promise<!settings.SearchRequest>} A signal indicating that
+     *     searching finished.
+     */
+    search: function(text, page) {}
+  };
+
   /**
    * @constructor
+   * @implements {SearchManager}
    */
-  var SearchManager = function() {
-    /** @private {?SearchRequest} */
+  var SearchManagerImpl = function() {
+    /** @private {?settings.SearchRequest} */
     this.activeRequest_ = null;
 
     /** @private {!TaskQueue} */
     this.queue_ = new TaskQueue();
     this.queue_.onEmpty(function() {
       this.activeRequest_.finished = true;
       this.activeRequest_.resolver.resolve(this.activeRequest_);
       this.activeRequest_ = null;
     }.bind(this));
   };
-  cr.addSingletonGetter(SearchManager);
+  cr.addSingletonGetter(SearchManagerImpl);
 
-  SearchManager.prototype = {
-    /**
-     * @param {string} text The text to search for.
-     * @param {!Node} page
-     * @return {!Promise<!SearchRequest>} A signal indicating that searching
-     *     finished.
-     */
+  SearchManagerImpl.prototype = {
+    /** @override */
     search: function(text, page) {
       // Creating a new request only if the |text| changed.
       if (!this.activeRequest_ || !this.activeRequest_.isSame(text)) {
         // Resolving previous search request without marking it as
-        // 'finisthed', if any, and droping all pending tasks.
+        // 'finished', if any, and dropping all pending tasks.
         this.queue_.reset();
         if (this.activeRequest_)
           this.activeRequest_.resolver.resolve(this.activeRequest_);
 
         this.activeRequest_ = new SearchRequest(text);
       }
 
       this.queue_.addTopLevelSearchTask(
           new TopLevelSearchTask(this.activeRequest_, page));
 
       return this.activeRequest_.resolver.promise;
     },
   };
 
   /** @return {!SearchManager} */
   function getSearchManager() {
-    return SearchManager.getInstance();
+    return SearchManagerImpl.getInstance();
+  }
+
+  /**
+   * Sets the SearchManager singleton instance, useful for testing.
+   * @param {!SearchManager} searchManager
+   */
+  function setSearchManagerForTesting(searchManager) {
+    SearchManagerImpl.instance_ = searchManager;
   }
 
   return {
     getSearchManager: getSearchManager,
+    setSearchManagerForTesting: setSearchManagerForTesting,
+    SearchRequest: SearchRequest,
   };
 });