Remove deprecated support to passing a class to `:class_name` on associations

2 files changed, 3 insertions, 10 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 2723b3dc03..d1c2286227 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1848,7 +1848,7 @@ module ActiveRecord
 
           builder = Builder::HasAndBelongsToMany.new name, self, options
 
-          join_model = ActiveSupport::Deprecation.silence { builder.through_model }
+          join_model = builder.through_model
 
           const_set join_model.name, join_model
           private_constant join_model.name
@@ -1877,7 +1877,7 @@ module ActiveRecord
             hm_options[k] = options[k] if options.key? k
           end
 
-          ActiveSupport::Deprecation.silence { has_many name, scope, hm_options, &extension }
+          has_many name, scope, hm_options, &extension
           _reflections[name.to_s].parent_reflection = habtm_reflection
         end
       end
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 97adfb4352..a60dad91d6 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -431,14 +431,7 @@ module ActiveRecord
         @association_scope_cache = Concurrent::Map.new
 
         if options[:class_name] && options[:class_name].class == Class
-          ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Passing a class to the `class_name` is deprecated and will raise
-            an ArgumentError in Rails 5.2. It eagerloads more classes than
-            necessary and potentially creates circular dependencies.
-
-            Please pass the class name as a string:
-            `#{macro} :#{name}, class_name: '#{options[:class_name]}'`
-          MSG
+          raise ArgumentError, "A class was passed to `:class_name` but we are expecting a string."
         end
       end