MD Settings: Allow trailing slashes in otherwise valid URLs.

chrome/browser/resources/settings/route.js

Index: chrome/browser/resources/settings/route.js
diff --git a/chrome/browser/resources/settings/route.js b/chrome/browser/resources/settings/route.js
index 082a46d3015bbb5cc8493b9a4b3b5967eeef5102..fe7612f7c8f62076ca1779d10741e7a8ddf38421 100644
--- a/chrome/browser/resources/settings/route.js
+++ b/chrome/browser/resources/settings/route.js
@@ -238,17 +238,27 @@ cr.define('settings', function() {
   };
 
   /**
-   * Returns the matching canonical route, or null if none matches.
+   * Regular expression that captures the leading slash, the content and the
+   * trailing slash in three different groups.
+   * @const {!RegExp}
+   */
+  var CANONICAL_PATH_REGEX = /(^\/)([\/-\w]{1,})(\/$)/;

[tommycli, 2016/11/24 00:02:51]

Any particular reason to use {1,} instead of +? just curious

[tommycli, 2016/11/24 00:04:07]

Instead of just "+"

Question mark is for the question, not for the non-greedy modifier lol

[dpapad, 2016/11/24 00:07:41]

Yes. I need to ensure that there is at least on character between the leading
and trailing slashes, otherwise this assertion in my test fails,

assertEquals(null, settings.getRouteForPath('//'));

because it returns BASIC instead of null. The user visible bug is that if user
navigates to 
chrome://md-settings// is considered a valid path, where as the expected
behavior is to be forwarded to
chrome://md-settings.

[dpapad, 2016/11/24 01:54:09]

Done. I double checked and {1,} is equivalent to + (I must have tried * instead
of + initially).

+
+  /**
    * @param {string} path
-   * @return {?settings.Route}
+   * @return {?settings.Route} The matching canonical route, or null if none
+   *     matches.
    */
   var getRouteForPath = function(path) {
+    // Allow trailing slash in paths.
+    var canonicalPath = path.replace(CANONICAL_PATH_REGEX, '$1$2');
+
     // TODO(tommycli): Use Object.values once Closure compilation supports it.
     var matchingKey = Object.keys(Route).find(function(key) {
-      return Route[key].path == path;
+      return Route[key].path == canonicalPath;
     });
 
-    return Route[matchingKey] || null;
+    return !!matchingKey ? Route[matchingKey] : null;
   };
 
   /**