server: add TTF font support

packages/ruby/server/lib/server/dir.rb

@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
 class Server::Dir
+  MIME_TYPES = {
+    ".ttf" => "font/ttf"
+  }.freeze
+
   def initialize(root)
     @root = File.realpath(root)
   end
@@ -24,8 +28,9 @@ class Server::Dir
 
   def read(path)
     body = File.binread(path)
+    extn = File.extname(path)
     [
-      {"content-type" => Rack::Mime.mime_type(File.extname(path)),
+      {"content-type" => MIME_TYPES[extn] || Rack::Mime.mime_type(extn),
        "content-length" => body.bytesize},
       body.each_line
     ]

packages/ruby/server/test/server_dir_test.rb

@@ -11,6 +11,14 @@ class ServerDirTest < Test::Unit::TestCase
     assert_equal bytesize("./test/fakeweb/index.html"), last_response.content_length
   end
 
+  def test_ttf_font
+    get "/fonts/roboto-mono-regular.ttf"
+    assert_equal 200, last_response.status
+    assert_equal "font/ttf", last_response.content_type
+    assert_equal bytesize("./test/fakeweb/fonts/roboto-mono-regular.ttf"),
+                 last_response.content_length
+  end
+
   def test_permission_denied
     File.chmod 0, "./test/fakeweb/permission_denied.html"
     get "/permission_denied.html"