1 files changed, 34 insertions, 0 deletions
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 55496147c1..d8bc917e7f 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -9,6 +9,7 @@ require "models/company"
 require "models/tagging"
 require "models/topic"
 require "models/reply"
+require "models/rating"
 require "models/entrant"
 require "models/project"
 require "models/developer"
@@ -156,6 +157,32 @@ class FinderTest < ActiveRecord::TestCase
     assert_raise(NoMethodError) { Topic.exists?([1, 2]) }
   end
 
+  def test_exists_with_scope
+    davids = Author.where(name: "David")
+    assert_equal true, davids.exists?
+    assert_equal true, davids.exists?(authors(:david).id)
+    assert_equal false, davids.exists?(authors(:mary).id)
+    assert_equal false, davids.exists?("42")
+    assert_equal false, davids.exists?(42)
+    assert_equal false, davids.exists?(davids.new.id)
+
+    fake = Author.where(name: "fake author")
+    assert_equal false, fake.exists?
+    assert_equal false, fake.exists?(authors(:david).id)
+  end
+
+  def test_exists_uses_existing_scope
+    post = authors(:david).posts.first
+    authors = Author.includes(:posts).where(name: "David", posts: { id: post.id })
+    assert_equal true, authors.exists?(authors(:david).id)
+  end
+
+  def test_any_with_scope_on_hash_includes
+    post = authors(:david).posts.first
+    categories = Categorization.includes(author: :posts).where(posts: { id: post.id })
+    assert_equal true, categories.exists?
+  end
+
   def test_exists_with_polymorphic_relation
     post = Post.create!(title: "Post", body: "default", taggings: [Tagging.new(comment: "tagging comment")])
     relation = Post.tagged_with_comment("tagging comment")
@@ -244,6 +271,13 @@ class FinderTest < ActiveRecord::TestCase
     assert_equal true, author.unique_categorized_posts.includes(:special_comments).order("comments.tags_count DESC").limit(1).exists?
   end
 
+  def test_exists_should_reference_correct_aliases_while_joining_tables_of_has_many_through_association
+    assert_nothing_raised do
+      developer = developers(:david)
+      developer.ratings.includes(comment: :post).where(posts: { id: 1 }).exists?
+    end
+  end
+
   def test_exists_with_empty_table_and_no_args_given
     Topic.delete_all
     assert_equal false, Topic.exists?