Only load Railtie if Rails exists.

lib/geocoder.rb

 require "geocoder/configuration"
 require "geocoder/calculations"
 require "geocoder/cache"
-require "geocoder/railtie"
 require "geocoder/request"
 
 module Geocoder
@@ -118,4 +117,8 @@ module Geocoder
   end
 end
 
-Geocoder::Railtie.insert
+# load Railtie if Rails exists
+if defined?(Rails)
+  require "geocoder/railtie"
+  Geocoder::Railtie.insert
+end

test/test_helper.rb

@@ -38,6 +38,10 @@ module ActiveRecord
   end
 end
 
+# simulate Rails module so Railtie gets loaded
+module Rails
+end
+
 # Require Geocoder after ActiveRecord simulator.
 require 'geocoder'
 require "geocoder/lookups/base"