Fix #increment! and #decrement! methods to behave similarly to the Rails' ActiveRecord methods

.github/workflows/ci.yml

@@ -39,9 +39,9 @@ jobs:
           - rails_6_1
           - rails_7_0
         rubygems:
-          - latest
+          - default
         bundler:
-          - latest
+          - default
         ruby:
           - "2.3"
           - "2.4"

lib/dynamoid/persistence.rb

@@ -8,6 +8,7 @@
 require 'dynamoid/persistence/update_fields'
 require 'dynamoid/persistence/upsert'
 require 'dynamoid/persistence/save'
+require 'dynamoid/persistence/inc'
 require 'dynamoid/persistence/update_validations'
 
 # encoding: utf-8
@@ -378,28 +379,21 @@ def upsert(hash_key_value, range_key_value = nil, attrs = {}, conditions = {})
       # Doesn't run validations and callbacks. Doesn't update +created_at+ and
       # +updated_at+ as well.
       #
+      # When `:touch` option is passed the timestamp columns are updating. If
+      # attribute names are passed, they are updated along with updated_at
+      # attribute:
+      #
+      #   User.inc('1', age: 2, touch: true)
+      #   User.inc('1', age: 2, touch: :viewed_at)
+      #   User.inc('1', age: 2, touch: [:viewed_at, :accessed_at])
+      #
       # @param hash_key_value [Scalar value] hash key
       # @param range_key_value [Scalar value] range key (optional)
       # @param counters [Hash] value to increase by
+      # @option counters [true | Symbol | Array[Symbol]] :touch to update update_at attribute and optionally the specified ones
       # @return [Model class] self
       def inc(hash_key_value, range_key_value = nil, counters)
-        options = if range_key
-                    value_casted = TypeCasting.cast_field(range_key_value, attributes[range_key])
-                    value_dumped = Dumping.dump_field(value_casted, attributes[range_key])
-                    { range_key: value_dumped }
-                  else
-                    {}
-                  end
-
-        Dynamoid.adapter.update_item(table_name, hash_key_value, options) do |t|
-          counters.each do |k, v|
-            value_casted = TypeCasting.cast_field(v, attributes[k])
-            value_dumped = Dumping.dump_field(value_casted, attributes[k])
-
-            t.add(k => value_dumped)
-          end
-        end
-
+        Inc.call(self, hash_key_value, range_key_value, counters)
         self
       end
     end
@@ -736,14 +730,28 @@ def increment(attribute, by = 1)
     #   user.increment!(:followers_count)
     #   user.increment!(:followers_count, 2)
     #
-    # Returns +true+ if a model was saved and +false+ otherwise.
+    # Only `attribute` is saved. The model itself is not saved. So any other
+    # modified attributes will still be dirty. Validations and callbacks are
+    # skipped.
+    #
+    # When `:touch` option is passed the timestamp columns are updating. If
+    # attribute names are passed, they are updated along with updated_at
+    # attribute:
+    #
+    #   user.increment!(:followers_count, touch: true)
+    #   user.increment!(:followers_count, touch: :viewed_at)
+    #   user.increment!(:followers_count, touch: [:viewed_at, :accessed_at])
     #
     # @param attribute [Symbol] attribute name
     # @param by [Numeric] value to add (optional)
-    # @return [true|false] whether saved model successfully
-    def increment!(attribute, by = 1)
+    # @param touch [true | Symbol | Array[Symbol]] to update update_at attribute and optionally the specified ones
+    # @return [Dynamoid::Document] self
+    def increment!(attribute, by = 1, touch: nil)
       increment(attribute, by)
-      save
+      change = read_attribute(attribute) - (attribute_was(attribute) || 0)
+      self.class.inc(hash_key, range_value, attribute => change, touch: touch)
+      clear_attribute_changes(attribute)
+      self
     end
 
     # Change numeric attribute value.
@@ -758,9 +766,7 @@ def increment!(attribute, by = 1)
     # @param by [Numeric] value to subtract (optional)
     # @return [Dynamoid::Document] self
     def decrement(attribute, by = 1)
-      self[attribute] ||= 0
-      self[attribute] -= by
-      self
+      increment(attribute, -by)
     end
 
     # Change numeric attribute value and save a model.
@@ -771,14 +777,24 @@ def decrement(attribute, by = 1)
     #   user.decrement!(:followers_count)
     #   user.decrement!(:followers_count, 2)
     #
-    # Returns +true+ if a model was saved and +false+ otherwise.
+    # Only `attribute` is saved. The model itself is not saved. So any other
+    # modified attributes will still be dirty. Validations and callbacks are
+    # skipped.
+    #
+    # When `:touch` option is passed the timestamp columns are updating. If
+    # attribute names are passed, they are updated along with updated_at
+    # attribute:
+    #
+    #   user.decrement!(:followers_count, touch: true)
+    #   user.decrement!(:followers_count, touch: :viewed_at)
+    #   user.decrement!(:followers_count, touch: [:viewed_at, :accessed_at])
     #
     # @param attribute [Symbol] attribute name
     # @param by [Numeric] value to subtract (optional)
-    # @return [true|false] whether saved model successfully
-    def decrement!(attribute, by = 1)
-      decrement(attribute, by)
-      save
+    # @param touch [true | Symbol | Array[Symbol]] to update update_at attribute and optionally the specified ones
+    # @return [Dynamoid::Document] self
+    def decrement!(attribute, by = 1, touch: nil)
+      increment!(attribute, -by, touch: touch)
     end
 
     # Delete a model.

lib/dynamoid/persistence/inc.rb

@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+module Dynamoid
+  module Persistence
+    # @private
+    class Inc
+      def self.call(model_class, hash_key, range_key = nil, counters)
+        new(model_class, hash_key, range_key, counters).call
+      end
+
+      # rubocop:disable Style/OptionalArguments
+      def initialize(model_class, hash_key, range_key = nil, counters)
+        @model_class = model_class
+        @hash_key = hash_key
+        @range_key = range_key
+        @counters = counters
+      end
+      # rubocop:enable Style/OptionalArguments
+
+      def call
+        touch = @counters.delete(:touch)
+
+        Dynamoid.adapter.update_item(@model_class.table_name, @hash_key, update_item_options) do |t|
+          @counters.each do |name, value|
+            t.add(name => cast_and_dump_attribute_value(name, value))
+          end
+
+          if touch
+            value = DateTime.now.in_time_zone(Time.zone)
+
+            timestamp_attributes_to_touch(touch).each do |name|
+              t.set(name => cast_and_dump_attribute_value(name, value))
+            end
+          end
+        end
+      end
+
+      private
+
+      def update_item_options
+        if @model_class.range_key
+          range_key_options = @model_class.attributes[@model_class.range_key]
+          value_casted = TypeCasting.cast_field(@range_key, range_key_options)
+          value_dumped = Dumping.dump_field(value_casted, range_key_options)
+          { range_key: value_dumped }
+        else
+          {}
+        end
+      end
+
+      def cast_and_dump_attribute_value(name, value)
+        value_casted = TypeCasting.cast_field(value, @model_class.attributes[name])
+        Dumping.dump_field(value_casted, @model_class.attributes[name])
+      end
+
+      def timestamp_attributes_to_touch(touch)
+        return [] unless touch
+
+        names = []
+        names << :updated_at if @model_class.timestamps_enabled?
+        names += Array.wrap(touch) if touch != true
+        names
+      end
+    end
+  end
+end