Add gzip helper to enable/disable HTTP::DeflateHandler

spec/helpers_spec.cr

@@ -122,4 +122,15 @@ describe "Macros" do
       response.headers["Content-Length"].should eq("6")
     end
   end
+
+  describe "#gzip" do
+    it "adds HTTP::DeflateHandler to handlers" do
+      gzip true
+      Kemal.config.handlers.last.is_a?(HTTP::DeflateHandler).should eq true
+    end
+
+    it "doesn't add HTTP::DeflateHandler to handlers by default" do
+      Kemal.config.handlers.last.is_a?(HTTP::DeflateHandler).should eq false
+    end
+  end
 end

src/kemal/helpers/helpers.cr

@@ -50,7 +50,7 @@ end
 #   send_file env, "./path/to/file", "image/jpeg"
 def send_file(env, path : String, mime_type : String? = nil)
   file_path = File.expand_path(path, Dir.current)
-  mime_type ||= "application/octet-stream" 
+  mime_type ||= "application/octet-stream"
   env.response.content_type = mime_type
   env.response.content_length = File.size(file_path)
   File.open(file_path) do |file|
@@ -70,4 +70,11 @@ def send_file(env, data : Slice(UInt8), mime_type : String? = nil)
   env.response.content_type = mime_type
   env.response.content_length = data.bytesize
   env.response.write data
-end
+end
+
+# Configures an `HTTP::Server::Response` to compress the response
+# output, either using gzip or deflate, depending on the `Accept-Encoding` request header.
+# It's disabled by default.
+def gzip(status : Bool = false)
+  add_handler HTTP::DeflateHandler.new if status
+end

src/kemal/static_file_handler.cr

@@ -9,7 +9,7 @@ module Kemal
       return call_next(context) if context.request.path.not_nil! == "/"
       super
     end
-    
+
     def mime_type(path)
       case File.extname(path)
       when ".txt"          then "text/plain"
@@ -23,6 +23,5 @@ module Kemal
       else                      "application/octet-stream"
       end
     end
-    
   end
 end