feat(middleware): add request logger and static file server

lib/prism/middleware/logger.rb

@@ -0,0 +1,18 @@
+module Prism
+  module Middleware
+    class Logger
+      def initialize(app, io: $stderr)
+        @app = app
+        @io = io
+      end
+
+      def call(env)
+        started = Time.now
+        status, headers, body = @app.call(env)
+        elapsed = ((Time.now - started) * 1000).round(2)
+        @io.puts(format('%s %s -> %d (%.2f ms)', env['REQUEST_METHOD'], env['PATH_INFO'], status, elapsed))
+        [status, headers, body]
+      end
+    end
+  end
+end

lib/prism/middleware/static.rb

@@ -0,0 +1,45 @@
+module Prism
+  module Middleware
+    class Static
+      ContentTypes = {
+        '.html' => 'text/html;charset=utf-8', '.htm' => 'text/html;charset=utf-8',
+        '.css' => 'text/css', '.js' => 'application/javascript', '.json' => 'application/json',
+        '.png' => 'image/png', '.jpg' => 'image/jpeg', '.jpeg' => 'image/jpeg', '.gif' => 'image/gif',
+        '.svg' => 'image/svg+xml', '.ico' => 'image/x-icon', '.txt' => 'text/plain', '.pdf' => 'application/pdf'
+      }.freeze
+
+      def initialize(app, root:)
+        @app = app
+        @root = File.expand_path(root)
+      end
+
+      def call(env)
+        method = env['REQUEST_METHOD']
+        return @app.call(env) unless %w[GET HEAD].include?(method)
+
+        file = resolve(env['PATH_INFO'])
+        return @app.call(env) unless file
+
+        serve(file)
+      end
+
+      private
+
+      def resolve(path_info)
+        return nil if path_info.nil? || path_info.include?("\0")
+        decoded = CGI.unescape(path_info)
+        candidate = File.expand_path(File.join(@root, decoded))
+        return nil unless candidate.start_with?("#{@root}#{File::SEPARATOR}") || candidate == @root
+        return File.join(candidate, 'index.html') if File.directory?(candidate) && File.file?(File.join(candidate, 'index.html'))
+        return nil unless File.file?(candidate)
+        candidate
+      end
+
+      def serve(file)
+        body = File.binread(file)
+        type = ContentTypes.fetch(File.extname(file).downcase, 'application/octet-stream')
+        [200, { 'Content-Type' => type, 'Content-Length' => body.bytesize.to_s }, [body]]
+      end
+    end
+  end
+end