Validate URLs

lib/manifique/agent.rb

@@ -1,15 +1,31 @@
+require 'uri'
 require "manifique/web_client"
 
 module Manifique
   class Agent
-    def initialize(options)
+    def initialize(options={})
       @options = options
-      @url = options[:url]
+
+      if url_valid?(options[:url])
+        @url = options[:url]
+      else
+        raise "No valid URL specified"
+      end
     end
 
     def fetch_metadata
       web_client = WebClient.new(url: @url)
       web_client.fetch_web_manifest
     end
+
+    private
+
+    def url_valid?(str)
+      return false unless str.class == String
+      url = URI.parse(str)
+      url.kind_of?(URI::HTTP) || url.kind_of?(URI::HTTPS)
+    rescue URI::InvalidURIError
+      false
+    end
   end
 end