Minor refactors

src/kemal/helpers/utils.cr

@@ -1,11 +1,13 @@
 module Kemal
   module Utils
+    ZIP_TYPES = [".htm", ".html", ".txt", ".css", ".js", ".svg", ".json", ".xml", ".otf", ".ttf", ".woff", ".woff2"]
+
     def self.path_starts_with_slash?(path : String)
       path.starts_with?("/")
     end
 
     def self.zip_types(path : String) # https://github.com/h5bp/server-configs-nginx/blob/master/nginx.conf
-      [".htm", ".html", ".txt", ".css", ".js", ".svg", ".json", ".xml", ".otf", ".ttf", ".woff", ".woff2"].includes? File.extname(path)
+      ZIP_TYPES.includes? File.extname(path)
     end
 
     def self.mime_type(path : String)

src/kemal/param_parser.cr

@@ -6,6 +6,7 @@ module Kemal
     URL_ENCODED_FORM = "application/x-www-form-urlencoded"
     APPLICATION_JSON = "application/json"
     MULTIPART_FORM   = "multipart/form-data"
+    PARTS = %w(url query body json)
     # :nodoc:
     alias AllParamTypes = Nil | String | Int64 | Float64 | Bool | Hash(String, JSON::Type) | Array(JSON::Type)
     getter files
@@ -28,7 +29,7 @@ module Kemal
       value
     end
 
-    {% for method in %w(url query body json) %}
+    {% for method in PARTS %}
       def {{method.id}}
         # check memoization
         return @{{method.id}} if @{{method.id}}_parsed

src/kemal/route_handler.cr

@@ -20,7 +20,7 @@ module Kemal
     # a corresponding `HEAD` route.
     def add_route(method : String, path : String, &handler : HTTP::Server::Context -> _)
       add_to_radix_tree method, path, Route.new(method, path, &handler)
-      add_to_radix_tree("HEAD", path, Route.new("HEAD", path) { |ctx| "" }) if method == "GET"
+      add_to_radix_tree("HEAD", path, Route.new("HEAD", path) {}) if method == "GET"
     end
 
     # Check if a route is defined and returns the lookup