5 files changed, 40 insertions, 9 deletions
diff --git a/activerecord/test/cases/adapters/mysql2/boolean_test.rb b/activerecord/test/cases/adapters/mysql2/boolean_test.rb
index 2fa39282fb..58698d59db 100644
--- a/activerecord/test/cases/adapters/mysql2/boolean_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/boolean_test.rb
@@ -38,7 +38,7 @@ class Mysql2BooleanTest < ActiveRecord::Mysql2TestCase
     assert_equal :string, string_column.type
   end
 
-  test "test type casting with emulated booleans" do
+  test "type casting with emulated booleans" do
     emulate_booleans true
 
     boolean = BooleanType.create!(archived: true, published: true)
@@ -55,7 +55,7 @@ class Mysql2BooleanTest < ActiveRecord::Mysql2TestCase
     assert_equal 0, @connection.type_cast(false)
   end
 
-  test "test type casting without emulated booleans" do
+  test "type casting without emulated booleans" do
     emulate_booleans false
 
     boolean = BooleanType.create!(archived: true, published: true)
diff --git a/activerecord/test/cases/cache_key_test.rb b/activerecord/test/cases/cache_key_test.rb
index bb2829b3c1..2c6a38ec35 100644
--- a/activerecord/test/cases/cache_key_test.rb
+++ b/activerecord/test/cases/cache_key_test.rb
@@ -15,7 +15,7 @@ module ActiveRecord
       @connection.drop_table :cache_mes, if_exists: true
     end
 
-    test "test_cache_key_format_is_not_too_precise" do
+    test "cache_key format is not too precise" do
       record = CacheMe.create
       key = record.cache_key
 
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 89d8a8bdca..4fa664697c 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -202,11 +202,24 @@ class FinderTest < ActiveRecord::TestCase
     assert_equal true, Topic.first.replies.exists?
   end
 
-  # ensures +exists?+ runs valid SQL by excluding order value
-  def test_exists_with_order
+  # Ensure +exists?+ runs without an error by excluding distinct value.
+  # See https://github.com/rails/rails/pull/26981.
+  def test_exists_with_order_and_distinct
     assert_equal true, Topic.order(:id).distinct.exists?
   end
 
+  def test_exists_with_joins
+    assert_equal true, Topic.joins(:replies).where(replies_topics: { approved: true }).order("replies_topics.created_at DESC").exists?
+  end
+
+  def test_exists_with_left_joins
+    assert_equal true, Topic.left_joins(:replies).where(replies_topics: { approved: true }).order("replies_topics.created_at DESC").exists?
+  end
+
+  def test_exists_with_eager_load
+    assert_equal true, Topic.eager_load(:replies).where(replies_topics: { approved: true }).order("replies_topics.created_at DESC").exists?
+  end
+
   def test_exists_with_includes_limit_and_empty_result
     assert_equal false, Topic.includes(:replies).limit(0).exists?
     assert_equal false, Topic.includes(:replies).limit(1).where("0 = 1").exists?
@@ -236,9 +249,9 @@ class FinderTest < ActiveRecord::TestCase
 
   def test_exists_with_aggregate_having_three_mappings_with_one_difference
     existing_address = customers(:david).address
-    assert_equal false, Customer.exists?(address:       Address.new(existing_address.street, existing_address.city, existing_address.country + "1"))
-    assert_equal false, Customer.exists?(address:       Address.new(existing_address.street, existing_address.city + "1", existing_address.country))
-    assert_equal false, Customer.exists?(address:       Address.new(existing_address.street + "1", existing_address.city, existing_address.country))
+    assert_equal false, Customer.exists?(address: Address.new(existing_address.street, existing_address.city, existing_address.country + "1"))
+    assert_equal false, Customer.exists?(address: Address.new(existing_address.street, existing_address.city + "1", existing_address.country))
+    assert_equal false, Customer.exists?(address: Address.new(existing_address.street + "1", existing_address.city, existing_address.country))
   end
 
   def test_exists_does_not_instantiate_records
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index 3720b0cc1a..a0a6d3c7ef 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -95,6 +95,24 @@ class FixturesTest < ActiveRecord::TestCase
     assert_nil(topics["second"]["author_email_address"])
   end
 
+  def test_no_args_returns_all
+    all_topics = topics
+    assert_equal 5, all_topics.length
+    assert_equal "The First Topic", all_topics.first["title"]
+    assert_equal 5, all_topics.last.id
+  end
+
+  def test_no_args_record_returns_all_without_array
+    all_binaries = binaries
+    assert_kind_of(Array, all_binaries)
+    assert_equal 1, binaries.length
+  end
+
+  def test_nil_raises
+    assert_raise(StandardError) { topics(nil) }
+    assert_raise(StandardError) { topics([nil]) }
+  end
+
   def test_inserts
     create_fixtures("topics")
     first_row = ActiveRecord::Base.connection.select_one("SELECT * FROM topics WHERE author_name = 'David'")
diff --git a/activerecord/test/cases/relation/mutation_test.rb b/activerecord/test/cases/relation/mutation_test.rb
index 4f92f71a09..11ef0d8743 100644
--- a/activerecord/test/cases/relation/mutation_test.rb
+++ b/activerecord/test/cases/relation/mutation_test.rb
@@ -143,7 +143,7 @@ module ActiveRecord
       assert_equal({ foo: "bar" }, relation.create_with_value)
     end
 
-    test "test_merge!" do
+    test "merge!" do
       assert relation.merge!(select: :foo).equal?(relation)
       assert_equal [:foo], relation.select_values
     end