Update router to handle method matching

src/kemal/handler.cr

@@ -25,8 +25,7 @@ class Kemal::Handler < HTTP::Handler
   def process_request(request)
     url = request.path.not_nil!
     @routes.each do |route|
-      url.match(route.pattern as Regex) do |url_params|
-        request.url_params = url_params
+      if route.match?(request)
         context = Context.new(request, route)
         begin
           body = route.handler.call(context).to_s

src/kemal/route.cr

@@ -3,10 +3,37 @@
 # what action to be done if the route is matched.
 class Kemal::Route
   getter handler
-  getter pattern
+  getter method
 
-  def initialize(@method, path, &@handler : Kemal::Context -> _)
-    @pattern = pattern_to_regex path
+  def initialize(@method, @path, &@handler : Kemal::Context -> _)
+  end
+
+  def match?(request)
+    check_for_method_override!(request)
+    return nil unless request.override_method == @method
+    return true if request.path.not_nil!.includes?(':') && request.path.not_nil! == @path
+    request.path.not_nil!.match(pattern_to_regex(@path)) do |url_params|
+      request.url_params = url_params
+      return true
+    end
+  end
+
+  # Checks if request params contain _method param to override request incoming method
+  def check_for_method_override!(request)
+    request.override_method = request.method
+    if request.method == "POST"
+      params = Kemal::ParamParser.new(self, request).parse_request
+      if params.has_key?("_method") && self.override_method_valid?(params["_method"])
+        request.override_method = params["_method"]
+      end
+    end
+  end
+
+  # Checks if method contained in _method param is valid one
+  def override_method_valid?(override_method)
+    return false unless override_method.is_a?(String)
+    override_method = override_method.upcase
+    return (override_method == "PUT" || override_method == "PATCH" || override_method == "DELETE")
   end
 
   private def pattern_to_regex(pattern)