sort routes for more specific results

This change sorts the routes to get the most specific routes first and
avoid hitting a route which is not the most specific match.
With this the regex to extract variables is made more strict to avoid
matching half of the URI.

lib/zero/router.rb

@@ -20,7 +20,7 @@ module Zero
     # match for variables in routes
     VARIABLE_MATCH = %r{:(\w+)[^/]?}
     # the replacement string to make it an regex
-    VARIABLE_REGEX = '(?<\1>.+?)'
+    VARIABLE_REGEX = '(?<\1>[\w]+?)'
     # regex part of the beginning of the line
     REGEX_BEGINNING = '\A'
     # regex part of the end of the line
@@ -41,7 +41,7 @@ module Zero
     # @param routes [Hash] a map of URLs to rack compatible applications
     def initialize(routes)
       @routes = {}
-      routes.each do |route, target|
+      routes.to_a.sort_by(&:first).reverse.each do |route, target|
         @routes[
           Regexp.new(REGEX_BEGINNING +
                      route.gsub(VARIABLE_MATCH, VARIABLE_REGEX) +

spec/unit/zero/router/call_spec.rb

@@ -44,6 +44,22 @@ describe Zero::Router, '#call' do
     it_behaves_like "a sample app"
   end
 
+  context 'with nested variable routes' do
+    let(:routes) do
+      { '/' => wrong_app, '/foo/:id' => app, '/foo/:id/bar' => wrong_app }
+    end
+    let(:env) { EnvGenerator.get('/foo/23') }
+    it_behaves_like "a sample app"
+  end
+
+  context 'with nested routes and variable in the middle' do
+    let(:routes) do
+      { '/' => wrong_app, '/foo/:id' => wrong_app, '/foo/:id/bar' => app }
+    end
+    let(:env) { EnvGenerator.get('/foo/23/bar') }
+    it_behaves_like "a sample app"
+  end
+
   context 'with a route not found' do
     let(:routes) {{ '/foo' => wrong_app, '/foo/bar/baz' => app }}
     let(:env) { EnvGenerator.get('/foo/bar') }
@@ -72,4 +88,19 @@ describe Zero::Router, '#call' do
 
     it_behaves_like 'a sample app'
   end
+
+  context 'with parameters and nested routes' do
+    let(:routes) do
+      { '/' => wrong_app, '/foo/:id' => app, '/foo/:id/bar' => wrong_app }
+    end
+    let(:env) { EnvGenerator.get('/foo/bar') }
+    let(:app) do
+      lambda do |env|
+        [200, content_type, [Zero::Request.new(env).params['id']]]
+      end
+    end
+    let(:result) { ['bar'] }
+
+    it_behaves_like "a sample app"
+  end
 end