Add Oxford commas [ci-skip]

guides/source/active_record_migrations.md

@@ -252,7 +252,7 @@ end
 ```
 
 This migration will create a `user_id` column. [References](#references) are a
-shorthand for creating columns, indexes, foreign keys or even polymorphic
+shorthand for creating columns, indexes, foreign keys, or even polymorphic
 association columns.
 
 There is also a generator which will produce join tables if `JoinTable` is part of the name:
@@ -281,7 +281,7 @@ end
 
 ### Model Generators
 
-The model, resource and scaffold generators will create migrations appropriate for adding
+The model, resource, and scaffold generators will create migrations appropriate for adding
 a new model. This migration will already contain instructions for creating the
 relevant table. If you tell Rails what columns you want, then statements for
 adding these columns will also be created. For example, running:
@@ -340,7 +340,7 @@ get to work!
 ### Creating a Table
 
 The [`create_table`][] method is one of the most fundamental, but most of the time,
-will be generated for you from using a model, resource or scaffold generator. A typical
+will be generated for you from using a model, resource, or scaffold generator. A typical
 use would be
 
 ```ruby
@@ -562,7 +562,7 @@ For example, to add a foreign key on `articles.reviewer` referencing `authors.em
 add_foreign_key :articles, :authors, column: :reviewer, primary_key: :email
 ```
 
-Options such as `name`, `on_delete`, `if_not_exists`, `validate` and `deferrable`
+Options such as `name`, `on_delete`, `if_not_exists`, `validate`, and `deferrable`
 are described in the [`add_foreign_key`][] API.
 
 NOTE: Active Record only supports single column foreign keys. `execute` and

guides/source/active_support_core_extensions.md

@@ -3553,7 +3553,7 @@ date.end_of_minute # => Mon Jun 07 19:55:59 +0200 2010
 
 `beginning_of_minute` is aliased to [`at_beginning_of_minute`][DateTime#at_beginning_of_minute].
 
-INFO: `beginning_of_hour`, `end_of_hour`, `beginning_of_minute` and `end_of_minute` are implemented for `Time` and `DateTime` but **not** `Date` as it does not make sense to request the beginning or end of an hour or minute on a `Date` instance.
+INFO: `beginning_of_hour`, `end_of_hour`, `beginning_of_minute`, and `end_of_minute` are implemented for `Time` and `DateTime` but **not** `Date` as it does not make sense to request the beginning or end of an hour or minute on a `Date` instance.
 
 NOTE: Defined in `active_support/core_ext/date_time/calculations.rb`.
 
@@ -3808,7 +3808,7 @@ NOTE: Defined in `active_support/core_ext/time/calculations.rb`.
 [DateAndTime::Calculations#tomorrow?]: https://api.rubyonrails.org/classes/DateAndTime/Calculations.html#method-i-tomorrow-3F
 [DateAndTime::Calculations#yesterday?]: https://api.rubyonrails.org/classes/DateAndTime/Calculations.html#method-i-yesterday-3F
 
-#### `all_day`, `all_week`, `all_month`, `all_quarter` and `all_year`
+#### `all_day`, `all_week`, `all_month`, `all_quarter`, and `all_year`
 
 The method [`all_day`][DateAndTime::Calculations#all_day] returns a range representing the whole day of the current time.
 

guides/source/configuring.md

@@ -369,7 +369,7 @@ Defines the CSS compressor to use. It is set by default by `sass-rails`. The uni
 
 #### `config.assets.js_compressor`
 
-Defines the JavaScript compressor to use. Possible values are `:terser`, `:closure`, `:uglifier` and `:yui`, which require the use of the `terser`, `closure-compiler`, `uglifier` or `yui-compressor` gems respectively.
+Defines the JavaScript compressor to use. Possible values are `:terser`, `:closure`, `:uglifier`, and `:yui`, which require the use of the `terser`, `closure-compiler`, `uglifier`, or `yui-compressor` gems respectively.
 
 #### `config.assets.gzip`
 
@@ -1884,7 +1884,7 @@ The default value depends on the `config.load_defaults` target version:
 
 Specifies what serializer the `MessageEncryptor` class will use by default.
 
-Options are `:json`, `:hybrid` and `:marshal`. `:hybrid` uses the `JsonWithMarshalFallback` class.
+Options are `:json`, `:hybrid`, and `:marshal`. `:hybrid` uses the `JsonWithMarshalFallback` class.
 
 The default value depends on the `config.load_defaults` target version:
 
@@ -2042,7 +2042,7 @@ By default, this is defined as:
 config.active_storage.analyzers = [ActiveStorage::Analyzer::ImageAnalyzer::Vips, ActiveStorage::Analyzer::ImageAnalyzer::ImageMagick, ActiveStorage::Analyzer::VideoAnalyzer, ActiveStorage::Analyzer::AudioAnalyzer]
 ```
 
-The image analyzers can extract width and height of an image blob; the video analyzer can extract width, height, duration, angle, aspect ratio and presence/absence of video/audio channels of a video blob; the audio analyzer can extract duration and bit rate of an audio blob.
+The image analyzers can extract width and height of an image blob; the video analyzer can extract width, height, duration, angle, aspect ratio, and presence/absence of video/audio channels of a video blob; the audio analyzer can extract duration and bit rate of an audio blob.
 
 #### `config.active_storage.previewers`
 

guides/source/generators.md

@@ -206,7 +206,7 @@ $ bin/rails generate scaffold User name:string
       create    test/system/users_test.rb
 ```
 
-Looking at this output, it's easy to understand how generators work in Rails 3.0 and above. The scaffold generator doesn't actually generate anything; it just invokes others to do the work. This allows us to add/replace/remove any of those invocations. For instance, the scaffold generator invokes the `scaffold_controller` generator, which invokes `erb`, `test_unit` and `helper` generators. Since each generator has a single responsibility, they are easy to reuse, avoiding code duplication.
+Looking at this output, it's easy to understand how generators work in Rails 3.0 and above. The scaffold generator doesn't actually generate anything; it just invokes others to do the work. This allows us to add/replace/remove any of those invocations. For instance, the scaffold generator invokes the `scaffold_controller` generator, which invokes `erb`, `test_unit`, and `helper` generators. Since each generator has a single responsibility, they are easy to reuse, avoiding code duplication.
 
 The next customization on the workflow will be to stop generating stylesheet and test fixture files for scaffolds altogether. We can achieve that by changing our configuration to the following:
 

guides/source/layouts_and_rendering.md

@@ -956,7 +956,7 @@ You can also specify a special size tag, in the format "{width}x{height}":
 <%= image_tag "home.gif", size: "50x20" %>
 ```
 
-In addition to the above special tags, you can supply a final hash of standard HTML options, such as `:class`, `:id` or `:name`:
+In addition to the above special tags, you can supply a final hash of standard HTML options, such as `:class`, `:id`, or `:name`:
 
 ```erb
 <%= image_tag "home.gif", alt: "Go Home",

guides/source/routing.md

@@ -89,7 +89,7 @@ Resource routing allows you to quickly declare all of the common routes for a gi
 
 ### Resources on the Web
 
-Browsers request pages from Rails by making a request for a URL using a specific HTTP method, such as `GET`, `POST`, `PATCH`, `PUT` and `DELETE`. Each method is a request to perform an operation on the resource. A resource route maps a number of related requests to actions in a single controller.
+Browsers request pages from Rails by making a request for a URL using a specific HTTP method, such as `GET`, `POST`, `PATCH`, `PUT`, and `DELETE`. Each method is a request to perform an operation on the resource. A resource route maps a number of related requests to actions in a single controller.
 
 When your Rails application receives an incoming request for: