Use an object to pass in the external environment dependencies

Author: monkbroc

README.md

@@ -87,16 +87,25 @@ MailInterceptor::Interceptor.new({ forward_emails_to: ['intercepted_emails@bigbi
                                                        'qa@bigbinary.com' })
 ```
 
-### Custom environment name
+### Custom environment
 
 If your staging environment is using the same Rails environment as
-production, you can pass in the the name of the environment and whether
-to intercept mail as options. The default is to use `Rails.env` and
-intercept mail in all environments except production.
+production, you can pass in an object with the name of the environment
+and whether to intercept mail as an option. The default is to use
+`Rails.env` and intercept mail in all environments except production.
 
 ```ruby
-MailInterceptor::Interceptor.new({ env_name: ENV["INSTANCE_NAME"],
-                                   intercept_mail?: ENV["INTERCEPT_MAIL"] == '1',
+class MyEnv
+  def name
+    ENV["INSTANCE_NAME"]
+  end
+
+  def intercept?
+    ENV["INTERCEPT_MAIL"] == '1'
+  end
+end
+
+MailInterceptor::Interceptor.new({ env: MyEnv.new,
                                    forward_emails_to: ['intercepted_emails@bigbinary.com',
                                    'qa@bigbinary.com' })
 ```

lib/mail_interceptor.rb

@@ -4,14 +4,13 @@
 
 module MailInterceptor
   class Interceptor
-    attr_accessor :deliver_emails_to, :forward_emails_to, :subject_prefix
+    attr_accessor :deliver_emails_to, :forward_emails_to, :subject_prefix, :env
 
     def initialize options = {}
       @deliver_emails_to = Array.wrap options[:deliver_emails_to]
       @subject_prefix    = options[:subject_prefix] || ''
       @forward_emails_to = options.fetch :forward_emails_to
-      @env_name          = options.fetch :env_name, default_env_name
-      @intercept_mail    = options.fetch :intercept_mail?, default_intercept_mail?
+      @env               = options.fetch :env, InterceptorEnv.new
 
       add_env_info_to_subject_prefix
       sanitize_forward_emails_to
@@ -24,13 +23,8 @@ def delivering_email message
 
     private
 
-    attr_reader :env_name
-    def intercept_mail?
-      @intercept_mail
-    end
-
     def normalize_recipients recipients
-      return Array.wrap(recipients) unless intercept_mail?
+      return Array.wrap(recipients) unless env.intercept?
 
       return forward_emails_to if deliver_emails_to.empty?
 
@@ -52,28 +46,30 @@ def add_subject_prefix message
     def sanitize_forward_emails_to
       self.forward_emails_to = Array.wrap forward_emails_to
 
-      if forward_emails_to_empty? && intercept_mail?
+      if forward_emails_to_empty? && env.intercept?
         raise "forward_emails_to should not be empty"
       end
     end
 
     def add_env_info_to_subject_prefix
       return if subject_prefix.blank?
 
-      _prefix = intercept_mail? ? "#{subject_prefix} #{env_name.upcase}" : subject_prefix
+      _prefix = env.intercept? ? "#{subject_prefix} #{env.name}" : subject_prefix
       self.subject_prefix = "[#{_prefix}]"
     end
 
     def forward_emails_to_empty?
       Array.wrap(forward_emails_to).reject(&:blank?).empty?
     end
+  end
 
-    def default_intercept_mail?
-      !Rails.env.production?
+  class InterceptorEnv
+    def name
+      Rails.env.upcase
     end
 
-    def default_env_name
-      Rails.env
+    def intercept?
+      !Rails.env.production?
     end
   end
 end

test/mail_interceptor_test.rb

@@ -9,42 +9,47 @@ class MailInterceptorTest < Minitest::Test
 
   def setup
     @message = OpenStruct.new
-    stub_env_methods('test')
   end
 
   def test_normalized_deliver_emails_to
-    @interceptor = ::MailInterceptor::Interceptor.new forward_emails_to: 'test@example.com'
+    @interceptor = ::MailInterceptor::Interceptor.new env: env,
+                                                      forward_emails_to: 'test@example.com'
     assert_equal [], @interceptor.deliver_emails_to
 
-    @interceptor = ::MailInterceptor::Interceptor.new forward_emails_to: 'test@example.com',
-                                                       deliver_emails_to: '@wheel.com'
+    @interceptor = ::MailInterceptor::Interceptor.new env: env,
+                                                      forward_emails_to: 'test@example.com',
+                                                      deliver_emails_to: '@wheel.com'
     assert_equal ["@wheel.com"], @interceptor.deliver_emails_to
 
-    @interceptor = ::MailInterceptor::Interceptor.new  forward_emails_to: 'test@example.com',
-                                                        deliver_emails_to: ['@wheel.com', '@pump.com']
+    @interceptor = ::MailInterceptor::Interceptor.new  env: env,
+                                                       forward_emails_to: 'test@example.com',
+                                                       deliver_emails_to: ['@wheel.com', '@pump.com']
     assert_equal ["@wheel.com", "@pump.com"], @interceptor.deliver_emails_to
   end
 
   def test_invocation_of_regular_expression
-    interceptor = ::MailInterceptor::Interceptor.new forward_emails_to: 'test@example.com',
-                                                      deliver_emails_to: ['@wheel.com', '@pump.com', 'john@gmail.com']
+    interceptor = ::MailInterceptor::Interceptor.new env: env,
+                                                     forward_emails_to: 'test@example.com',
+                                                     deliver_emails_to: ['@wheel.com', '@pump.com', 'john@gmail.com']
     @message.to = [ 'a@wheel.com', 'b@wheel.com', 'c@pump.com', 'd@club.com', 'e@gmail.com', 'john@gmail.com', 'sam@gmail.com']
     interceptor.delivering_email @message
     assert_equal ["a@wheel.com", "b@wheel.com", "c@pump.com", "test@example.com", "john@gmail.com"], @message.to
   end
 
   def test_no_subject_prefix_in_test
-    interceptor = ::MailInterceptor::Interceptor.new forward_emails_to: 'test@example.com',
-                                                       subject_prefix: nil
+    interceptor = ::MailInterceptor::Interceptor.new env: env,
+                                                     forward_emails_to: 'test@example.com',
+                                                     subject_prefix: nil
     @message.subject = 'Forgot password'
 
     interceptor.delivering_email @message
     assert_equal "Forgot password", @message.subject
   end
 
   def test_subject_prefix_in_test
-    interceptor = ::MailInterceptor::Interceptor.new forward_emails_to: 'test@example.com',
-                                                       subject_prefix: 'wheel'
+    interceptor = ::MailInterceptor::Interceptor.new env: env,
+                                                     forward_emails_to: 'test@example.com',
+                                                     subject_prefix: 'wheel'
     @message.subject = 'Forgot password'
 
     interceptor.delivering_email @message
@@ -55,24 +60,12 @@ def test_subject_prefix_in_test
     assert_equal "[wheel TEST] Another Forgot password", @message.subject
   end
 
-  def test_subject_prefix_in_custom_staging
-    stub_env_methods('production')
-    interceptor = ::MailInterceptor::Interceptor.new env_name: 'staging',
-                                                     intercept_mail?: true,
+  def test_subject_prefix_in_production
+    interceptor = ::MailInterceptor::Interceptor.new env: env('production'),
                                                      forward_emails_to: 'test@example.com',
                                                      subject_prefix: 'wheel'
     @message.subject = 'Forgot password'
 
-    interceptor.delivering_email @message
-    assert_equal "[wheel STAGING] Forgot password", @message.subject
-  end
-
-  def test_subject_prefix_in_production
-    stub_env_methods('production')
-    interceptor = ::MailInterceptor::Interceptor.new forward_emails_to: 'test@example.com',
-                                                       subject_prefix: 'wheel'
-    @message.subject = 'Forgot password'
-
     interceptor.delivering_email @message
     assert_equal "[wheel] Forgot password", @message.subject
   end
@@ -81,31 +74,34 @@ def test_error_if_forward_emails_to_is_empty
     message = "forward_emails_to should not be empty"
 
     exception = assert_raises(RuntimeError) do
-      ::MailInterceptor::Interceptor.new forward_emails_to: '',
-                                          subject_prefix: 'wheel'
+      ::MailInterceptor::Interceptor.new env: env,
+                                         forward_emails_to: '',
+                                         subject_prefix: 'wheel'
     end
 
     assert_equal message, exception.message
 
     exception =  assert_raises(RuntimeError) do
-      ::MailInterceptor::Interceptor.new forward_emails_to: [],
-                                          subject_prefix: 'wheel'
+      ::MailInterceptor::Interceptor.new env: env,
+                                         forward_emails_to: [],
+                                         subject_prefix: 'wheel'
     end
 
     assert_equal message, exception.message
 
     exception =  assert_raises(RuntimeError) do
-      ::MailInterceptor::Interceptor.new forward_emails_to: [''],
-                                          subject_prefix: 'wheel'
+      ::MailInterceptor::Interceptor.new env: env,
+                                         forward_emails_to: [''],
+                                         subject_prefix: 'wheel'
     end
 
     assert_equal message, exception.message
   end
 
   private
 
-  def stub_env_methods(env)
-    ::MailInterceptor::Interceptor.any_instance.stubs(:default_env_name).returns(env)
-    ::MailInterceptor::Interceptor.any_instance.stubs(:default_intercept_mail?).returns(env != 'production')
+  def env(environment = 'test')
+    OpenStruct.new :name => environment.upcase,
+                   :intercept? => environment != 'production'
   end
 end