Merge pull request #14871 from kassio/kb-fixes-namespaced-habtm

Fix how to compute class name on habtm namespaced.

Conflicts:
	activerecord/CHANGELOG.md

7 files changed, 43 insertions, 1 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 5797d62441..4588ef1ac9 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,10 @@
+*   Fix how to calculate associated class name when using namespaced `has_and_belongs_to_many`
+    association.
+
+    Fixes #14709.
+
+    *Kassio Borges*
+
 *   `ActiveRecord::Relation::Merger#filter_binds` now compares equivalent symbols and
     strings in column names as equal.
 
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 e472277374..ad781e50c9 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
@@ -23,7 +23,11 @@ module ActiveRecord::Associations::Builder
           KnownTable.new options[:join_table].to_s
         else
           class_name = options.fetch(:class_name) {
-            name.to_s.camelize.singularize
+            model_name = name.to_s.camelize.singularize
+            if parent_name = lhs_class.parent_name.presence
+              model_name = model_name.prepend("#{parent_name}::")
+            end
+            model_name
           }
           KnownClass.new lhs_class, class_name
         end
diff --git a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
index cfdfff6af9..878f1877db 100644
--- a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
@@ -22,6 +22,9 @@ require 'models/sponsor'
 require 'models/country'
 require 'models/treaty'
 require 'models/vertex'
+require 'models/publisher'
+require 'models/publisher/article'
+require 'models/publisher/magazine'
 require 'active_support/core_ext/string/conversions'
 
 class ProjectWithAfterCreateHook < ActiveRecord::Base
@@ -848,4 +851,13 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
   def test_custom_join_table
     assert_equal 'edges', Vertex.reflect_on_association(:sources).join_table
   end
+
+  def test_namespaced_habtm
+    magazine = Publisher::Magazine.create
+    article = Publisher::Article.create
+    magazine.articles << article
+    magazine.save
+
+    assert_includes magazine.articles, article
+  end
 end
diff --git a/activerecord/test/models/publisher.rb b/activerecord/test/models/publisher.rb
new file mode 100644
index 0000000000..0d4a7f9235
--- /dev/null
+++ b/activerecord/test/models/publisher.rb
@@ -0,0 +1,2 @@
+module Publisher
+end
diff --git a/activerecord/test/models/publisher/article.rb b/activerecord/test/models/publisher/article.rb
new file mode 100644
index 0000000000..03a277bbdd
--- /dev/null
+++ b/activerecord/test/models/publisher/article.rb
@@ -0,0 +1,3 @@
+class Publisher::Article < ActiveRecord::Base
+  has_and_belongs_to_many :magazines
+end
diff --git a/activerecord/test/models/publisher/magazine.rb b/activerecord/test/models/publisher/magazine.rb
new file mode 100644
index 0000000000..82e1a14008
--- /dev/null
+++ b/activerecord/test/models/publisher/magazine.rb
@@ -0,0 +1,3 @@
+class Publisher::Magazine < ActiveRecord::Base
+  has_and_belongs_to_many :articles
+end
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index da3074e90f..a78074d530 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -62,6 +62,14 @@ ActiveRecord::Schema.define do
     t.string :name
   end
 
+  create_table :articles, force: true do |t|
+  end
+
+  create_table :articles_magazines, force: true do |t|
+    t.references :article
+    t.references :magazine
+  end
+
   create_table :audit_logs, force: true do |t|
     t.column :message, :string, null: false
     t.column :developer_id, :integer, null: false
@@ -385,6 +393,9 @@ ActiveRecord::Schema.define do
     t.column :custom_lock_version, :integer
   end
 
+  create_table :magazines, force: true do |t|
+  end
+
   create_table :mateys, id: false, force: true do |t|
     t.column :pirate_id, :integer
     t.column :target_id, :integer