Add #create_or_find_by to lean on unique constraints (#31989)

Add #create_or_find_by to lean on unique constraints

1 files changed, 29 insertions, 0 deletions

diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index bc7c54dbe0..18e0bed5b6 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -22,6 +22,7 @@ require "models/reader"
 require "models/category"
 require "models/categorization"
 require "models/edge"
+require "models/subscriber"
 
 class RelationTest < ActiveRecord::TestCase
   fixtures :authors, :author_addresses, :topics, :entrants, :developers, :companies, :developers_projects, :accounts, :categories, :categorizations, :categories_posts, :posts, :comments, :tags, :taggings, :cars, :minivans
@@ -1349,6 +1350,34 @@ class RelationTest < ActiveRecord::TestCase
     assert_raises(ActiveRecord::RecordInvalid) { Bird.find_or_create_by!(color: "green") }
   end
 
+  def test_create_or_find_by
+    assert_nil Subscriber.find_by(nick: "bob")
+
+    subscriber = Subscriber.create!(nick: "bob")
+
+    assert_equal subscriber, Subscriber.create_or_find_by(nick: "bob")
+    assert_not_equal subscriber, Subscriber.create_or_find_by(nick: "cat")
+  end
+
+  def test_create_or_find_by_with_non_unique_attributes
+    Subscriber.create!(nick: "bob", name: "the builder")
+
+    assert_raises(ActiveRecord::RecordNotFound) do
+      Subscriber.create_or_find_by(nick: "bob", name: "the cat")
+    end
+  end
+
+  def test_create_or_find_by_within_transaction
+    assert_nil Subscriber.find_by(nick: "bob")
+
+    subscriber = Subscriber.create!(nick: "bob")
+
+    Subscriber.transaction do
+      assert_equal subscriber, Subscriber.create_or_find_by(nick: "bob")
+      assert_not_equal subscriber, Subscriber.create_or_find_by(nick: "cat")
+    end
+  end
+
   def test_find_or_initialize_by
     assert_nil Bird.find_by(name: "bob")