Rename association option :class to :anonymous_class

In 1f006c an option was added called :class to allow passing anonymous
classes to association definitions. Since using :class instead of
:class_name is a fairly common typo even amongst experienced developers
this can result in hard to debug errors arising in raise_on_type_mismatch?

To fix this we're renaming the option from :class to :anonymous_class as
that is a more correct description of what the option is for. Since this
was an internal, undocumented option there is no need for a deprecation.

Fixes #19659

3 files changed, 4 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/associations/builder/association.rb b/activerecord/lib/active_record/associations/builder/association.rb
index 88406740d8..ba1b1814d1 100644
--- a/activerecord/lib/active_record/associations/builder/association.rb
+++ b/activerecord/lib/active_record/associations/builder/association.rb
@@ -16,7 +16,7 @@ module ActiveRecord::Associations::Builder
     end
     self.extensions = []
 
-    VALID_OPTIONS = [:class_name, :class, :foreign_key, :validate] # :nodoc:
+    VALID_OPTIONS = [:class_name, :anonymous_class, :foreign_key, :validate] # :nodoc:
 
     def self.build(model, name, scope, options, &block)
       if model.dangerous_attribute_method?(name)
diff --git a/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb b/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
index 97b57a6a55..ffd9c9d6fc 100644
--- a/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
+++ b/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
@@ -78,7 +78,7 @@ module ActiveRecord::Associations::Builder
       join_model.table_name_resolver = habtm
       join_model.class_resolver      = lhs_model
 
-      join_model.add_left_association :left_side, class: lhs_model
+      join_model.add_left_association :left_side, anonymous_class: lhs_model
       join_model.add_right_association association_name, belongs_to_options(options)
       join_model
     end
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 4265afc0a5..1b0ae2c942 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -196,7 +196,7 @@ module ActiveRecord
         @scope         = scope
         @options       = options
         @active_record = active_record
-        @klass         = options[:class]
+        @klass         = options[:anonymous_class]
         @plural_name   = active_record.pluralize_table_names ?
                             name.to_s.pluralize : name.to_s
       end
@@ -635,7 +635,7 @@ module ActiveRecord
 
       def initialize(delegate_reflection)
         @delegate_reflection = delegate_reflection
-        @klass         = delegate_reflection.options[:class]
+        @klass         = delegate_reflection.options[:anonymous_class]
         @source_reflection_name = delegate_reflection.options[:source]
       end