Fix nil values in mapbox result

lib/geocoder/results/mapbox.rb

@@ -16,33 +16,43 @@ def street
     end
 
     def city
-      context_part('place')
+      data_part('place') || context_part('place')
     end
 
     def state
-      context_part('region')
+      data_part('region') || context_part('region')
     end
 
     def state_code
-      value = context_part('region', 'short_code')
+      if id_matches_name?(data['id'], 'region')
+        value = data['properties']['short_code']
+      else
+        value = context_part('region', 'short_code')
+      end
+
       value.split('-').last unless value.nil?
     end
 
     def postal_code
-      context_part('postcode')
+      data_part('postcode') || context_part('postcode')
     end
 
     def country
-      context_part('country')
+      data_part('country') || context_part('country')
     end
 
     def country_code
-      value = context_part('country', 'short_code')
+      if id_matches_name?(data['id'], 'country')
+        value = data['properties']['short_code']
+      else
+        value = context_part('country', 'short_code')
+      end
+
       value.upcase unless value.nil?
     end
 
     def neighborhood
-      context_part('neighborhood')
+      data_part('neighborhood') || context_part('neighborhood')
     end
 
     def address
@@ -51,8 +61,16 @@ def address
 
     private
 
+    def id_matches_name?(id, name)
+      id =~ Regexp.new(name)
+    end
+
+    def data_part(name)
+      data['text'] if id_matches_name?(data['id'], name)
+    end
+
     def context_part(name, key = 'text')
-      (context.detect { |c| c['id'] =~ Regexp.new(name) } || {})[key]
+      (context.detect { |c| id_matches_name?(c['id'], name) } || {})[key]
     end
 
     def context