Mocking fix refactored

Less hackier way to fix mocking invoking `to_str` method which resulted to raising error with missing client even from separeted units of API client  (as signal was bubbling to top module)

Author: DraCzris

lib/kosapi_client/kosapi_client.rb

@@ -1,48 +1,44 @@
 module KOSapiClient
 
+  DEFAULT_KOSAPI_BASE_URL = 'https://kosapi.fit.cvut.cz/api/3'
+
   singleton_class.class_eval do
 
-    def new(options = {})
-      ApiClient.new(Configuration.new(options))
+    attr_reader :client
+    
+    alias_method :to_str, :to_s
+
+    def new(credentials, base_url = DEFAULT_KOSAPI_BASE_URL)
+      http_adapter = OAuth2HttpAdapter.new(credentials, base_url)
+      http_client = HTTPClient.new(http_adapter)
+      ApiClient.new(http_client, base_url)
     end
 
     def configure
-      reset
+      config = Configuration.new
       yield config
-      self
-    end
-
-    def client
-      @client ||= ApiClient.new(config)
+      @client = new(config.credentials)
     end
 
     # Calling this method clears stored ApiClient instance
     # if configured previously.
     def reset
-      @config = nil
       @client = nil
     end
 
     def method_missing(method, *args, &block)
-      if client.respond_to?(method)
-        client.send(method, *args, &block)
+      if @client.nil?
+        raise "Client not configured. Either you forgot to call configure or you have typo in method name '#{method}'."
+      end
+      if @client.respond_to?(method)
+        @client.send(method, *args, &block)
       else
         super
       end
     end
 
     def respond_to_missing?(method_name, include_private = false)
-      client.respond_to?(method_name, include_private)
-    end
-
-    private
-    def config
-      @config ||= Configuration.new
-    end
-
-    # Was interfering with mocking
-    def to_str
-      "KOSapi client"
+      @client.respond_to?(method_name, include_private)
     end
   end
 end