Merge pull request #14395 from arthurnn/fix_mailer_preview_test

Fix MailerPreview broken tests

actionmailer/test/base_test.rb

@@ -594,7 +594,7 @@ def welcome
   test "you can register a preview interceptor to the mail object that gets passed the mail object before previewing" do
     ActionMailer::Base.register_preview_interceptor(MyInterceptor)
     mail = BaseMailer.welcome
-    BaseMailerPreview.stubs(:welcome).returns(mail)
+    BaseMailerPreview.any_instance.stubs(:welcome).returns(mail)
     MyInterceptor.expects(:previewing_email).with(mail)
     BaseMailerPreview.call(:welcome)
   end
@@ -602,7 +602,7 @@ def welcome
   test "you can register a preview interceptor using its stringified name to the mail object that gets passed the mail object before previewing" do
     ActionMailer::Base.register_preview_interceptor("BaseTest::MyInterceptor")
     mail = BaseMailer.welcome
-    BaseMailerPreview.stubs(:welcome).returns(mail)
+    BaseMailerPreview.any_instance.stubs(:welcome).returns(mail)
     MyInterceptor.expects(:previewing_email).with(mail)
     BaseMailerPreview.call(:welcome)
   end
@@ -610,7 +610,7 @@ def welcome
   test "you can register an interceptor using its symbolized underscored name to the mail object that gets passed the mail object before previewing" do
     ActionMailer::Base.register_preview_interceptor(:"base_test/my_interceptor")
     mail = BaseMailer.welcome
-    BaseMailerPreview.stubs(:welcome).returns(mail)
+    BaseMailerPreview.any_instance.stubs(:welcome).returns(mail)
     MyInterceptor.expects(:previewing_email).with(mail)
     BaseMailerPreview.call(:welcome)
   end
@@ -618,7 +618,7 @@ def welcome
   test "you can register multiple preview interceptors to the mail object that both get passed the mail object before previewing" do
     ActionMailer::Base.register_preview_interceptors("BaseTest::MyInterceptor", MySecondInterceptor)
     mail = BaseMailer.welcome
-    BaseMailerPreview.stubs(:welcome).returns(mail)
+    BaseMailerPreview.any_instance.stubs(:welcome).returns(mail)
     MyInterceptor.expects(:previewing_email).with(mail)
     MySecondInterceptor.expects(:previewing_email).with(mail)
     BaseMailerPreview.call(:welcome)