Introduce Kemal::InitHandler to initialize HTTP::Server::Context with defaults

spec/config_spec.cr

@@ -26,7 +26,7 @@ describe "Config" do
   it "adds a custom handler" do
     config = Kemal.config
     config.add_handler CustomTestHandler.new
-    config.handlers.size.should eq(5)
+    config.handlers.size.should eq(6)
   end
 
   it "adds custom options" do

spec/context_spec.cr

@@ -1,15 +1,6 @@
 require "./spec_helper"
 
 describe "Context" do
-  it "has a default content type" do
-    get "/" do |env|
-      "Hello"
-    end
-    request = HTTP::Request.new("GET", "/")
-    client_response = call_request_on_app(request)
-    client_response.headers["Content-Type"].should eq("text/html")
-  end
-
   it "sets content type" do
     get "/" do |env|
       env.response.content_type = "application/json"

spec/helpers_spec.cr

@@ -4,7 +4,7 @@ describe "Macros" do
   describe "#basic_auth" do
     it "adds HTTPBasicAuthHandler" do
       basic_auth "serdar", "123"
-      Kemal.config.handlers.size.should eq 5
+      Kemal.config.handlers.size.should eq 6
     end
   end
 
@@ -18,7 +18,7 @@ describe "Macros" do
   describe "#add_handler" do
     it "adds a custom handler" do
       add_handler CustomTestHandler.new
-      Kemal.config.handlers.size.should eq 5
+      Kemal.config.handlers.size.should eq 6
     end
   end
 

spec/init_handler_spec.cr

@@ -0,0 +1,21 @@
+require "./spec_helper"
+
+describe "Kemal::InitHandler" do
+  it "initializes context with Content-Type: text/html" do
+    request = HTTP::Request.new("GET", "/")
+    io = MemoryIO.new
+    response = HTTP::Server::Response.new(io)
+    context = HTTP::Server::Context.new(request, response)
+    Kemal::InitHandler::INSTANCE.call(context)
+    context.response.headers["Content-Type"].should eq "text/html"
+  end
+
+  it "initializes context with X-Powered-By: Kemal" do
+    request = HTTP::Request.new("GET", "/")
+    io = MemoryIO.new
+    response = HTTP::Server::Response.new(io)
+    context = HTTP::Server::Context.new(request, response)
+    Kemal::InitHandler::INSTANCE.call(context)
+    context.response.headers["X-Powered-By"].should eq "Kemal"
+  end
+end

spec/route_handler_spec.cr

@@ -155,20 +155,4 @@ describe "Kemal::RouteHandler" do
     client_response.status_code.should eq(302)
     client_response.headers.has_key?("Location").should eq(true)
   end
-
-  it "sets default Content-Type to context html" do
-    get "/" do |env|
-      "Hello World from GET"
-    end
-    request = HTTP::Request.new("GET", "/")
-    client_response = call_request_on_app(request)
-    client_response.content_type.should eq("text/html")
-  end
-
-  it "sets X-Powered-By to Kemal" do
-    get "/" { }
-    request = HTTP::Request.new("GET", "/")
-    client_response = call_request_on_app(request)
-    client_response.headers["X-Powered-By"].should eq("Kemal")
-  end
 end

src/kemal/common_exception_handler.cr

@@ -7,12 +7,10 @@ module Kemal
       begin
         call_next(context)
       rescue Kemal::Exceptions::RouteNotFound
-        context.response.content_type = "text/html"
         call_exception_with_status_code(context, 404)
       rescue Kemal::Exceptions::CustomException
         call_exception_with_status_code(context, context.response.status_code)
       rescue ex : Exception
-        context.response.content_type = "text/html"
         Kemal.config.logger.write("Exception: #{ex.inspect_with_backtrace}\n")
         return call_exception_with_status_code(context, 500) if Kemal.config.error_handlers.has_key?(500)
         verbosity = Kemal.config.env == "production" ? false : true

src/kemal/config.cr

@@ -58,33 +58,38 @@ module Kemal
       ERROR_HANDLERS[status_code] = ->(context : HTTP::Server::Context) { handler.call(context).to_s }
     end
 
+    def extra_options(&@extra_options : OptionParser ->)
+    end
+
     def setup
+      setup_init_handler
       setup_log_handler
       setup_error_handler
       setup_static_file_handler
     end
 
-    def setup_log_handler
+    private def setup_init_handler
+      HANDLERS.insert(0, Kemal::InitHandler::INSTANCE)
+    end
+
+    private def setup_log_handler
       @logger ||= if @logging
                     Kemal::CommonLogHandler.new
                   else
                     Kemal::NullLogHandler.new
                   end
-      HANDLERS.insert(0, @logger.not_nil!)
-    end
-
-    def extra_options(&@extra_options : OptionParser ->)
+      HANDLERS.insert(1, @logger.not_nil!)
     end
 
     private def setup_error_handler
       if @always_rescue
         @error_handler ||= Kemal::CommonExceptionHandler.new
-        HANDLERS.insert(1, @error_handler.not_nil!)
+        HANDLERS.insert(2, @error_handler.not_nil!)
       end
     end
 
     private def setup_static_file_handler
-      HANDLERS.insert(2, Kemal::StaticFileHandler.new(@public_folder)) if @serve_static
+      HANDLERS.insert(3, Kemal::StaticFileHandler.new(@public_folder)) if @serve_static
     end
   end
 

src/kemal/init_handler.cr

@@ -0,0 +1,12 @@
+module Kemal
+  # Kemal::InitHandler is the first handler thus initializes the context with default values such as
+  # Content-Type, X-Powered-By.
+  class InitHandler < HTTP::Handler
+    INSTANCE = new
+
+    def call(context)
+      context.response.content_type = "text/html"
+      context.response.headers.add "X-Powered-By", "Kemal"
+    end
+  end
+end

src/kemal/route_handler.cr

@@ -13,8 +13,6 @@ module Kemal
     end
 
     def call(context)
-      context.response.headers.add "X-Powered-By", "Kemal"
-      context.response.content_type = "text/html" unless context.response.headers.has_key?("Content-Type")
       process_request(context)
     end
 

src/kemal/view.cr

@@ -48,7 +48,6 @@ def render_500(context, backtrace, verbosity)
       </body>
       </html>
   HTML
-  context.response.content_type = "text/html"
   context.response.status_code = 500
   context.response.print template
   context