Fix grammar `a` to `an` [ci skip]

actioncable/lib/action_cable/connection/base.rb

@@ -35,7 +35,7 @@ module Connection
     #
     # First, we declare that this connection can be identified by its current_user. This allows us later to be able to find all connections
     # established for that current_user (and potentially disconnect them if the user was removed from an account). You can declare as many
-    # identification indexes as you like. Declaring an identification means that a attr_accessor is automatically set for that key.
+    # identification indexes as you like. Declaring an identification means that an attr_accessor is automatically set for that key.
     #
     # Second, we rely on the fact that the WebSocket connection is established with the cookies from the domain being sent along. This makes
     # it easy to use signed cookies that were set when logging in via a web interface to authorize the WebSocket connection.

actioncable/lib/action_cable/server/broadcasting.rb

@@ -23,7 +23,7 @@ def broadcast(broadcasting, message)
         broadcaster_for(broadcasting).broadcast(message)
       end
 
-      # Returns a broadcaster for a named <tt>broadcasting</tt> that can be reused. Useful when you have a object that
+      # Returns a broadcaster for a named <tt>broadcasting</tt> that can be reused. Useful when you have an object that
       # may need multiple spots to transmit to a specific broadcasting over and over.
       def broadcaster_for(broadcasting)
         Broadcaster.new(self, broadcasting)

actionview/CHANGELOG.md

@@ -68,7 +68,7 @@
 
     *Vasiliy Ermolovich*
 
-*   Add a `hidden_field` on the `collection_radio_buttons` to avoid raising a error
+*   Add a `hidden_field` on the `collection_radio_buttons` to avoid raising an error
     when the only input on the form is the `collection_radio_buttons`.
 
     *Mauro George*

activerecord/lib/active_record/callbacks.rb

@@ -179,7 +179,7 @@ module ActiveRecord
   #
   # If the +before_validation+ callback throws +:abort+, the process will be
   # aborted and {ActiveRecord::Base#save}[rdoc-ref:Persistence#save] will return +false+.
-  # If {ActiveRecord::Base#save!}[rdoc-ref:Persistence#save!] is called it will raise a ActiveRecord::RecordInvalid exception.
+  # If {ActiveRecord::Base#save!}[rdoc-ref:Persistence#save!] is called it will raise an ActiveRecord::RecordInvalid exception.
   # Nothing will be appended to the errors object.
   #
   # == Canceling callbacks

activerecord/lib/active_record/relation/finder_methods.rb

@@ -330,7 +330,7 @@ def exists?(conditions = :none)
     end
 
     # This method is called whenever no records are found with either a single
-    # id or multiple ids and raises a ActiveRecord::RecordNotFound exception.
+    # id or multiple ids and raises an ActiveRecord::RecordNotFound exception.
     #
     # The error message is different depending on whether a single id or
     # multiple ids are provided. If multiple ids are provided, then the number

activerecord/lib/active_record/sanitization.rb

@@ -60,7 +60,7 @@ def sanitize_sql_for_assignment(assignments, default_table_name = self.table_nam
       end
 
       # Accepts an array, or string of SQL conditions and sanitizes
-      # them into a valid SQL fragment for a ORDER clause.
+      # them into a valid SQL fragment for an ORDER clause.
       #
       #   sanitize_sql_for_order(["field(id, ?)", [1,3,2]])
       #   # => "field(id, 1,3,2)"

activerecord/lib/active_record/validations.rb

@@ -45,7 +45,7 @@ def save(options={})
     end
 
     # Attempts to save the record just like {ActiveRecord::Base#save}[rdoc-ref:Base#save] but
-    # will raise a ActiveRecord::RecordInvalid exception instead of returning +false+ if the record is not valid.
+    # will raise an ActiveRecord::RecordInvalid exception instead of returning +false+ if the record is not valid.
     def save!(options={})
       perform_validations(options) ? super : raise_validation_error
     end

activerecord/test/cases/finder_test.rb

@@ -101,7 +101,7 @@ def test_find_with_ids_and_limit
 
   def test_find_with_ids_where_and_limit
     # Please note that Topic 1 is the only not approved so
-    # if it were among the first 3 it would raise a ActiveRecord::RecordNotFound
+    # if it were among the first 3 it would raise an ActiveRecord::RecordNotFound
     records = Topic.where(approved: true).limit(3).find([3,2,5,1,4])
     assert_equal 3, records.size
     assert_equal 'The Third Topic of the day',  records[0].title

guides/source/action_mailer_basics.md

@@ -222,7 +222,7 @@ class SendWeeklySummary
 end
 ```
 
-The method `welcome_email` returns a `ActionMailer::MessageDelivery` object which
+The method `welcome_email` returns an `ActionMailer::MessageDelivery` object which
 can then just be told `deliver_now` or `deliver_later` to send itself out. The
 `ActionMailer::MessageDelivery` object is just a wrapper around a `Mail::Message`. If
 you want to inspect, alter or do anything else with the `Mail::Message` object you can

guides/source/action_view_overview.md

@@ -1524,7 +1524,7 @@ Localized Views
 
 Action View has the ability to render different templates depending on the current locale.
 
-For example, suppose you have a `ArticlesController` with a show action. By default, calling this action will render `app/views/articles/show.html.erb`. But if you set `I18n.locale = :de`, then `app/views/articles/show.de.html.erb` will be rendered instead. If the localized template isn't present, the undecorated version will be used. This means you're not required to provide localized views for all cases, but they will be preferred and used if available.
+For example, suppose you have an `ArticlesController` with a show action. By default, calling this action will render `app/views/articles/show.html.erb`. But if you set `I18n.locale = :de`, then `app/views/articles/show.de.html.erb` will be rendered instead. If the localized template isn't present, the undecorated version will be used. This means you're not required to provide localized views for all cases, but they will be preferred and used if available.
 
 You can use the same technique to localize the rescue files in your public directory. For example, setting `I18n.locale = :de` and creating `public/500.de.html` and `public/404.de.html` would allow you to have localized rescue pages.
 

guides/source/active_model_basics.md

@@ -319,7 +319,7 @@ person.serializable_hash   # => {"name"=>"Bob"}
 
 #### ActiveModel::Serializers
 
-Rails provides a `ActiveModel::Serializers::JSON` serializer.
+Rails provides an `ActiveModel::Serializers::JSON` serializer.
 This module automatically include the `ActiveModel::Serialization`.
 
 ##### ActiveModel::Serializers::JSON

guides/source/engines.md

@@ -461,7 +461,7 @@ model, a comment controller and then modify the articles scaffold to display
 comments and allow people to create new ones.
 
 From the application root, run the model generator. Tell it to generate a
-`Comment` model, with the related table having two columns: a `article_id` integer
+`Comment` model, with the related table having two columns: an `article_id` integer
 and `text` text column.
 
 ```bash

guides/source/layouts_and_rendering.md

@@ -555,7 +555,7 @@ class Admin::ProductsController < AdminController
 end
 ```
 
-The lookup order for a `admin/products#index` action will be:
+The lookup order for an `admin/products#index` action will be:
 
 * `app/views/admin/products/`
 * `app/views/admin/`

guides/source/upgrading_ruby_on_rails.md

@@ -183,7 +183,7 @@ the logs. In the next version, these errors will no longer be suppressed.
 Instead, the errors will propagate normally just like in other Active
 Record callbacks.
 
-When you define a `after_rollback` or `after_commit` callback, you
+When you define an `after_rollback` or `after_commit` callback, you
 will receive a deprecation warning about this upcoming change. When
 you are ready, you can opt into the new behavior and remove the
 deprecation warning by adding following configuration to your