From c03fddfa0a64cc839f08391f7b4aea881a421e2c Mon Sep 17 00:00:00 2001
From: Drew Tempelmeyer <drewtempelmeyer@users.noreply.github.com>
Date: Mon, 10 Jan 2022 15:53:27 -0600
Subject: [PATCH] Add ActiveRecord::Persistence#update_attribute!

---
 activerecord/CHANGELOG.md                     | 23 +++++++
 activerecord/lib/active_record/persistence.rb | 24 ++++++-
 activerecord/test/cases/persistence_test.rb   | 63 +++++++++++++++++++
 3 files changed, 109 insertions(+), 1 deletion(-)

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 9e0422472a..9f6d4b2eda 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,26 @@
+*   Add `update_attribute!` to `ActiveRecord::Persistence`
+
+    Similar to `update_attribute`, but raises `ActiveRecord::RecordNotSaved` when a `before_*` callback throws `:abort`.
+
+    ```ruby
+    class Topic < ActiveRecord::Base
+      before_save :check_title
+
+      def check_title
+        throw(:abort) if title == "abort"
+      end
+    end
+
+    topic = Topic.create(title: "Test Title")
+    # #=> #<Topic title: "Test Title">
+    topic.update_attribute!(:title, "Another Title")
+    # #=> #<Topic title: "Another Title">
+    topic.update_attribute!(:title, "abort")
+    # raises ActiveRecord::RecordNotSaved
+    ```
+
+    *Drew Tempelmeyer*
+
 *   Avoid loading every record in `ActiveRecord::Relation#pretty_print`
 
     ```ruby
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 09c997d339..0d42905c59 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -747,7 +747,7 @@ module ActiveRecord
     # * updated_at/updated_on column is updated if that column is available.
     # * Updates all the attributes that are dirty in this object.
     #
-    # This method raises an ActiveRecord::ActiveRecordError  if the
+    # This method raises an ActiveRecord::ActiveRecordError if the
     # attribute is marked as readonly.
     #
     # Also see #update_column.
@@ -759,6 +759,28 @@ module ActiveRecord
       save(validate: false)
     end
 
+    # Updates a single attribute and saves the record.
+    # This is especially useful for boolean flags on existing records. Also note that
+    #
+    # * Validation is skipped.
+    # * \Callbacks are invoked.
+    # * updated_at/updated_on column is updated if that column is available.
+    # * Updates all the attributes that are dirty in this object.
+    #
+    # This method raises an ActiveRecord::ActiveRecordError if the
+    # attribute is marked as readonly.
+    #
+    # If any of the <tt>before_*</tt> callbacks throws +:abort+ the action is cancelled
+    # and #update_attribute! raises ActiveRecord::RecordNotSaved. See
+    # ActiveRecord::Callbacks for further details.
+    def update_attribute!(name, value)
+      name = name.to_s
+      verify_readonly_attribute(name)
+      public_send("#{name}=", value)
+
+      save!(validate: false)
+    end
+
     # Updates the attributes of the model from the passed-in hash and saves the
     # record, all wrapped in a transaction. If the object is invalid, the saving
     # will fail and false will be returned.
diff --git a/activerecord/test/cases/persistence_test.rb b/activerecord/test/cases/persistence_test.rb
index 0eca43bb67..3e7ec69dc3 100644
--- a/activerecord/test/cases/persistence_test.rb
+++ b/activerecord/test/cases/persistence_test.rb
@@ -813,6 +813,69 @@ class PersistenceTest < ActiveRecord::TestCase
     assert_not_equal prev_month, developer.updated_at
   end
 
+  def test_update_attribute!
+    assert_not_predicate Topic.find(1), :approved?
+    Topic.find(1).update_attribute!("approved", true)
+    assert_predicate Topic.find(1), :approved?
+
+    Topic.find(1).update_attribute!(:approved, false)
+    assert_not_predicate Topic.find(1), :approved?
+
+    Topic.find(1).update_attribute!(:change_approved_before_save, true)
+    assert_predicate Topic.find(1), :approved?
+  end
+
+  def test_update_attribute_for_readonly_attribute!
+    minivan = Minivan.find("m1")
+    assert_raises(ActiveRecord::ActiveRecordError) { minivan.update_attribute!(:color, "black") }
+  end
+
+  def test_update_attribute_with_one_updated!
+    t = Topic.first
+    t.update_attribute!(:title, "super_title")
+    assert_equal "super_title", t.title
+    assert_not t.changed?, "topic should not have changed"
+    assert_not t.title_changed?, "title should not have changed"
+    assert_nil t.title_change, "title change should be nil"
+
+    t.reload
+    assert_equal "super_title", t.title
+  end
+
+  def test_update_attribute_for_updated_at_on!
+    developer = Developer.find(1)
+    prev_month = Time.now.prev_month.change(usec: 0)
+
+    developer.update_attribute!(:updated_at, prev_month)
+    assert_equal prev_month, developer.updated_at
+
+    developer.update_attribute!(:salary, 80001)
+    assert_not_equal prev_month, developer.updated_at
+
+    developer.reload
+    assert_not_equal prev_month, developer.updated_at
+  end
+
+  def test_update_attribute_for_aborted_callback!
+    klass = Class.new(Topic) do
+      def self.name; "Topic"; end
+
+      before_update :throw_abort
+
+      def throw_abort
+        throw(:abort)
+      end
+    end
+
+    t = klass.create(title: "New Topic", author_name: "Not David")
+
+    assert_raises(ActiveRecord::RecordNotSaved) { t.update_attribute!(:title, "super_title") }
+
+    t_reloaded = Topic.find(t.id)
+
+    assert_equal "New Topic", t_reloaded.title
+  end
+
   def test_update_column
     topic = Topic.find(1)
     topic.update_column("approved", true)