From 4faaa811614b408b32422692ce36024442d02ffb Mon Sep 17 00:00:00 2001
From: Marc-Andre Lafortune <github@marc-andre.ca>
Date: Tue, 5 Jun 2012 02:35:05 -0400
Subject: [PATCH] + ActiveRecord::Base#destroy!

---
 activerecord/CHANGELOG.md                     |  5 +++++
 activerecord/lib/active_record/errors.rb      |  4 ++++
 activerecord/lib/active_record/persistence.rb | 16 ++++++++++++++++
 activerecord/test/cases/callbacks_test.rb     |  2 ++
 activerecord/test/cases/persistence_test.rb   |  7 +++++++
 5 files changed, 34 insertions(+)

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index b04c54ce7f369..55cc85a63d55a 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,5 +1,10 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Added `#destroy!` which acts like `#destroy` but will raise an
+    `ActiveRecord::RecordNotDestroyed` exception instead of returning `false`.
+
+    *Marc-André Lafortune*
+
 *   Allow blocks for `count` with `ActiveRecord::Relation`, to work similar as
     `Array#count`:
 
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index fc80f3081e0bc..9b88bb81789cd 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -53,6 +53,10 @@ class RecordNotFound < ActiveRecordError
   class RecordNotSaved < ActiveRecordError
   end
 
+  # Raised by ActiveRecord::Base.destroy! when a call to destroy would return false.
+  class RecordNotDestroyed < ActiveRecordError
+  end
+
   # Raised when SQL statement cannot be executed by the database (for example, it's often the case for
   # MySQL when Ruby driver used is too old).
   class StatementInvalid < ActiveRecordError
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index a1bc39a32d1cc..ec5670ba6ef76 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -122,6 +122,11 @@ def delete
 
     # Deletes the record in the database and freezes this instance to reflect
     # that no changes should be made (since they can't be persisted).
+    #
+    # There's a series of callbacks associated with <tt>destroy</tt>. If
+    # the <tt>before_destroy</tt> callback return +false+ the action is cancelled
+    # and <tt>destroy</tt> returns +false+. See
+    # ActiveRecord::Callbacks for further details.
     def destroy
       raise ReadOnlyRecord if readonly?
       destroy_associations
@@ -130,6 +135,17 @@ def destroy
       freeze
     end
 
+    # Deletes the record in the database and freezes this instance to reflect
+    # that no changes should be made (since they can't be persisted).
+    #
+    # There's a series of callbacks associated with <tt>destroy!</tt>. If
+    # the <tt>before_destroy</tt> callback return +false+ the action is cancelled
+    # and <tt>destroy!</tt> raises ActiveRecord::RecordNotDestroyed. See
+    # ActiveRecord::Callbacks for further details.
+    def destroy!
+      destroy || raise(ActiveRecord::RecordNotDestroyed)
+    end
+
     # Returns an instance of the specified +klass+ with the attributes of the
     # current record. This is mostly useful in relation to single-table
     # inheritance structures where you want a subclass to appear as the
diff --git a/activerecord/test/cases/callbacks_test.rb b/activerecord/test/cases/callbacks_test.rb
index 769076922605f..deeef3a3fdbfe 100644
--- a/activerecord/test/cases/callbacks_test.rb
+++ b/activerecord/test/cases/callbacks_test.rb
@@ -426,11 +426,13 @@ def test_before_update_returning_false
   def test_before_destroy_returning_false
     david = ImmutableDeveloper.find(1)
     assert !david.destroy
+    assert_raise(ActiveRecord::RecordNotDestroyed) { david.destroy! }
     assert_not_nil ImmutableDeveloper.find_by_id(1)
 
     someone = CallbackCancellationDeveloper.find(1)
     someone.cancel_before_destroy = true
     assert !someone.destroy
+    assert_raise(ActiveRecord::RecordNotDestroyed) { someone.destroy! }
     assert !someone.after_destroy_called
   end
 
diff --git a/activerecord/test/cases/persistence_test.rb b/activerecord/test/cases/persistence_test.rb
index 0933a4ff3d196..fecdf2b7056b5 100644
--- a/activerecord/test/cases/persistence_test.rb
+++ b/activerecord/test/cases/persistence_test.rb
@@ -305,6 +305,13 @@ def test_destroy
     assert_raise(ActiveRecord::RecordNotFound) { Topic.find(topic.id) }
   end
 
+  def test_destroy!
+    topic = Topic.find(1)
+    assert_equal topic, topic.destroy!, 'topic.destroy! did not return self'
+    assert topic.frozen?, 'topic not frozen after destroy!'
+    assert_raise(ActiveRecord::RecordNotFound) { Topic.find(topic.id) }
+  end
+
   def test_record_not_found_exception
     assert_raise(ActiveRecord::RecordNotFound) { Topic.find(99999) }
   end