Implement save! (#1)

lib/active_model_persistence.rb

@@ -5,6 +5,8 @@
 
 # A set of mixins to add to ActiveModel classes to support persistence
 #
+# @api public
+#
 module ActiveModelPersistence
   # A base class for all ActiveModelPersistence errors
   class ModelError < StandardError; end
@@ -14,6 +16,33 @@ class ObjectNotInIndexError < ModelError; end
 
   # Raised when trying to add an object to an index when the key already exists in the index for another object
   class UniqueConstraintError < ModelError; end
+
+  # Raised when trying to save an invalid object
+  class ObjectNotSavedError < ModelError
+    # The object that was not saved
+    #
+    # @example
+    #   object = Object.new
+    #   error = ObjectNotSavedError.new('Invalid object', object)
+    #   error.object == object #=> true
+    #
+    # @return [Object] The object that was not saved
+    #
+    attr_reader :object
+
+    # Create a new error
+    #
+    # @example
+    #   ObjectNotSavedError.new('Invalid object', self)
+    #
+    # @param message [String] The error message
+    # @param object [Object] The object that was not saved
+    #
+    def initialize(message = nil, object = nil)
+      @object = object
+      super(message)
+    end
+  end
 end
 
 require_relative 'active_model_persistence/index'

lib/active_model_persistence/persistence.rb

@@ -14,6 +14,7 @@ module ActiveModelPersistence
   #     attribute :id, :integer
   #     attribute :name, :string
   #     index :id, unique: true
+  #     validates :id, presence: true
   #   end
   #
   #   # Creating a model instance with `.new` does not save it to the object store
@@ -274,6 +275,28 @@ def save(**_options, &block)
         result != false
       end
 
+      # Calls #save and raises an error if #save returns false
+      #
+      # @example
+      #   object = ModelExample.new(id: nil, name: 'James')
+      #   object.save! #=> raises ObjectNotSavedError
+      #
+      # @param _options [Hash] save options (currently unused)
+      #
+      # @param block [Proc] a block to call after the save
+      #
+      # @yield [self] a block to call after the save
+      # @yieldparam saved_model [self] the model object after it was saved
+      # @yieldreturn [void]
+      #
+      # @raise [ObjectNotSavedError] if the model object was not saved
+      #
+      # @return [Boolean] returns true or raises an error
+      #
+      def save!(**options, &block)
+        save(**options, &block) || raise(ObjectNotSavedError.new('Failed to save the object', self))
+      end
+
       # Deletes the object from the object store
       #
       # This model object is frozen to reflect that no changes should be made

spec/active_model_persistence/persistence_spec.rb

@@ -101,6 +101,15 @@
       end
     end
 
+    describe '#save!' do
+      context 'for an invalid object' do
+        let(:object) { model_class.new }
+        it 'should raise an error' do
+          expect { object.save! }.to raise_error(ActiveModelPersistence::ObjectNotSavedError)
+        end
+      end
+    end
+
     describe '#save' do
       let(:object) { model_class.new(attributes) }
       before do