In Browser Path Matching with Javascript

When debugging routes ,it can sometimes be difficult to understand exactly how the paths are matched. This PR adds a JS based path matching widget to the `/rails/info/routes` output. You can enter in a path, and it will tell you which of the routes that path matches, while preserving order (top match wins).

The matching widget in action:

![](http://f.cl.ly/items/3A2F0v2m3m1Z1p3P3O3k/path-match.gif)

Prior to this PR the only way to check matching paths is via mental math, or typing in a path in the url bar and seeing where it goes. This feature will be an invaluable debugging tool by dramatically decreasing the time needed to check a path match. 

ATP actionpack

actionpack/CHANGELOG.md

@@ -1,5 +1,10 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Add javascript based routing path matcher to `/rails/info/routes`.
+    Routes can now be filtered by whether or not they match a path.
+
+    *Richard Schneeman*
+
 *   Given
 
         params.permit(:name)

actionpack/lib/action_dispatch/middleware/templates/routes/_route.html.erb

@@ -7,7 +7,7 @@
   <td data-route-verb='<%= route[:verb] %>'>
     <%= route[:verb] %>
   </td>
-  <td data-route-path='<%= route[:path] %>'>
+  <td data-route-path='<%= route[:path] %>' data-regexp='<%= route[:regexp] %>'>
     <%= route[:path] %>
   </td>
   <td data-route-reqs='<%= route[:reqs] %>'>

actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb

@@ -1,22 +1,58 @@
 <% content_for :style do %>
-  #route_table td { padding: 0 30px; }
-  #route_table    { margin:  0 auto 0; }
+  #route_table {
+    margin: 0 auto 0;
+    border-collapse: collapse;
+  }
+
+  #route_table td {
+    padding: 0 30px;
+  }
+
+  #route_table tr.bottom th {
+    padding-bottom: 10px;
+    line-height: 15px;
+  }
+
+  #route_table .matched_paths {
+    background-color: LightGoldenRodYellow;
+  }
+
+  #route_table .matched_paths {
+    border-bottom: solid 3px SlateGrey;
+  }
+
+  #path_search {
+    width: 80%;
+    font-size: inherit;
+  }
 <% end %>
 
 <table id='route_table' class='route_table'>
   <thead>
     <tr>
-      <th>Helper<br />
-        <%= link_to "Path", "#", 'data-route-helper' => '_path',
-                    title: "Returns a relative path (without the http or domain)" %> /
-        <%= link_to "Url", "#", 'data-route-helper' => '_url',
-                    title: "Returns an absolute url (with the http and domain)" %>
-      </th>
+      <th>Helper</th>
       <th>HTTP Verb</th>
       <th>Path</th>
       <th>Controller#Action</th>
     </tr>
+    <tr class='bottom'>
+      <th><%# Helper %>
+        <%= link_to "Path", "#", 'data-route-helper' => '_path',
+                    title: "Returns a relative path (without the http or domain)" %> /
+        <%= link_to "Url", "#", 'data-route-helper' => '_url',
+                    title: "Returns an absolute url (with the http and domain)"   %>
+      </th>
+      <th><%# HTTP Verb %>
+      </th>
+      <th><%# Path %>
+        <%= search_field(:path, nil, id: 'path_search', placeholder: "Path Match") %>
+      </th>
+      <th><%# Controller#action %>
+      </th>
+    </tr>
   </thead>
+  <tbody class='matched_paths' id='matched_paths'>
+  </tbody>
   <tbody>
     <%= yield %>
   </tbody>
@@ -25,7 +61,7 @@
 <script type='text/javascript'>
   function each(elems, func) {
     if (!elems instanceof Array) { elems = [elems]; }
-    for (var i = elems.length; i--; ) {
+    for (var i = 0, len = elems.length; i < len; i++) {
       func(elems[i]);
     }
   }
@@ -46,11 +82,63 @@
   function setupRouteToggleHelperLinks() {
     var toggleLinks = document.querySelectorAll('#route_table [data-route-helper]');
     onClick(toggleLinks, function(){
-      var helperTxt   = this.getAttribute("data-route-helper");
-      var helperElems = document.querySelectorAll('[data-route-name] span.helper');
+      var helperTxt   = this.getAttribute("data-route-helper"),
+          helperElems = document.querySelectorAll('[data-route-name] span.helper');
       setValOn(helperElems, helperTxt);
     });
   }
 
+  // takes an array of elements with a data-regexp attribute and
+  // passes their their parent <tr> into the callback function
+  // if the regexp matchs a given path
+  function eachElemsForPath(elems, path, func) {
+    each(elems, function(e){
+      var reg = e.getAttribute("data-regexp");
+      if (path.match(RegExp(reg))) {
+        func(e.parentNode.cloneNode(true));
+      }
+    })
+  }
+
+  // Ensure path always starts with a slash "/" and remove params or fragments
+  function sanitizePath(path) {
+    var path = path.charAt(0) == '/' ? path : "/" + path;
+    return path.replace(/\#.*|\?.*/, '');
+  }
+
+  // Enables path search functionality
+  function setupMatchPaths() {
+    var regexpElems     = document.querySelectorAll('#route_table [data-regexp]'),
+        pathElem        = document.querySelector('#path_search'),
+        selectedSection = document.querySelector('#matched_paths'),
+        noMatchText     = '<tr><th colspan="4">None</th></tr>';
+
+
+    // Remove matches if no path is present
+    pathElem.onblur = function(e) {
+      if (pathElem.value === "") selectedSection.innerHTML = "";
+    }
+
+    // On key press perform a search for matching paths
+    pathElem.onkeyup = function(e){
+      var path        = sanitizePath(pathElem.value),
+          defaultText = '<tr><th colspan="4">Paths Matching (' + path + '):</th></tr>';
+
+      // Clear out results section
+      selectedSection.innerHTML= defaultText;
+
+      // Display matches if they exist
+      eachElemsForPath(regexpElems, path, function(e){
+        selectedSection.appendChild(e);
+      });
+
+      // If no match present, tell the user
+      if (selectedSection.innerHTML === defaultText) {
+        selectedSection.innerHTML = selectedSection.innerHTML + noMatchText;
+      }
+    }
+  }
+
+  setupMatchPaths();
   setupRouteToggleHelperLinks();
 </script>

actionpack/lib/action_dispatch/routing/inspector.rb

@@ -34,6 +34,23 @@ module ActionDispatch
         super.to_s
       end
 
+      def regexp
+        __getobj__.path.to_regexp
+      end
+
+      def json_regexp
+        str = regexp.inspect.
+              sub('\\A' , '^').
+              sub('\\Z' , '$').
+              sub('\\z' , '$').
+              sub(/^\// , '').
+              sub(/\/[a-z]*$/ , '').
+              gsub(/\(\?#.+\)/ , '').
+              gsub(/\(\?-\w+:/ , '(').
+              gsub(/\s/ , '')
+        Regexp.new(str).source
+      end
+
       def reqs
         @reqs ||= begin
           reqs = endpoint
@@ -101,7 +118,11 @@ module ActionDispatch
         end.collect do |route|
           collect_engine_routes(route)
 
-          { name: route.name, verb: route.verb, path: route.path, reqs: route.reqs }
+          { name:   route.name,
+            verb:   route.verb,
+            path:   route.path,
+            reqs:   route.reqs,
+            regexp: route.json_regexp }
         end
       end
 

actionpack/test/dispatch/routing/inspector_test.rb

@@ -21,6 +21,14 @@ module ActionDispatch
         inspector.format(ActionDispatch::Routing::ConsoleFormatter.new, options[:filter]).split("\n")
       end
 
+      def test_json_regexp_converter
+        @set.draw do
+          get '/cart', :to => 'cart#show'
+        end
+        route = ActionDispatch::Routing::RouteWrapper.new(@set.routes.first)
+        assert_equal "^\\/cart(?:\\.([^\\/.?]+))?$", route.json_regexp
+      end
+
       def test_displaying_routes_for_engines
         engine = Class.new(Rails::Engine) do
           def self.inspect