14 files changed, 39 insertions, 33 deletions
diff --git a/guides/source/2_2_release_notes.md b/guides/source/2_2_release_notes.md
index c6bac34d18..ac5833e069 100644
--- a/guides/source/2_2_release_notes.md
+++ b/guides/source/2_2_release_notes.md
@@ -45,7 +45,6 @@ The internal documentation of Rails, in the form of code comments, has been impr
 * [A Guide to Testing Rails Applications](testing.html)
 * [Securing Rails Applications](security.html)
 * [Debugging Rails Applications](debugging_rails_applications.html)
-* [Performance Testing Rails Applications](performance_testing.html)
 * [The Basics of Creating Rails Plugins](plugins.html)
 
 All told, the Guides provide tens of thousands of words of guidance for beginning and intermediate Rails developers.
diff --git a/guides/source/5_0_release_notes.md b/guides/source/5_0_release_notes.md
index 6538629972..50886a57a7 100644
--- a/guides/source/5_0_release_notes.md
+++ b/guides/source/5_0_release_notes.md
@@ -595,6 +595,9 @@ Please refer to the [Changelog][active-record] for detailed changes.
 *   Removed support for `activerecord-deprecated_finders` gem.
     ([commit](https://github.com/rails/rails/commit/78dab2a8569408658542e462a957ea5a35aa4679))
 
+*   Removed `ActiveRecord::ConnectionAdapters::Column::TRUE_VALUES` constant.
+    ([commit](https://github.com/rails/rails/commit/a502703c3d2151d4d3b421b29fefdac5ad05df61))
+
 ### Deprecations
 
 *   Deprecated passing a class as a value in a query. Users should pass strings
@@ -802,7 +805,8 @@ Please refer to the [Changelog][active-record] for detailed changes.
     were getting rescued and printed in the logs, unless you used
     the (newly deprecated) `raise_in_transactional_callbacks = true` option.
 
-    Now these errors are not rescued anymore and just bubble up, as the other callbacks.
+    Now these errors are not rescued anymore and just bubble up, matching the
+    behavior of other callbacks.
     ([commit](https://github.com/rails/rails/commit/07d3d402341e81ada0214f2cb2be1da69eadfe72))
 
 Active Model
diff --git a/guides/source/action_view_overview.md b/guides/source/action_view_overview.md
index e11466e79f..ff0127522b 100644
--- a/guides/source/action_view_overview.md
+++ b/guides/source/action_view_overview.md
@@ -254,12 +254,6 @@ as if we had written:
 <%= render partial: "product", locals: { product: @product } %>
 ```
 
-With the `as` option we can specify a different name for the local variable. For example, if we wanted it to be `item` instead of `product` we would do:
-
-```erb
-<%= render partial: "product", as: "item" %>
-```
-
 The `object` option can be used to directly specify which object is rendered into the partial; useful when the template's object is elsewhere (e.g. in a different instance variable or in a local variable).
 
 For example, instead of:
@@ -274,12 +268,18 @@ we would do:
 <%= render partial: "product", object: @item %>
 ```
 
-The `object` and `as` options can also be used together:
+With the `as` option we can specify a different name for the said local variable. For example, if we wanted it to be `item` instead of `product` we would do:
 
 ```erb
 <%= render partial: "product", object: @item, as: "item" %>
 ```
 
+This is equivalent to
+
+```erb
+<%= render partial: "product", locals: { item: @item } %>
+```
+
 #### Rendering Collections
 
 It is very common that a template will need to iterate over a collection and render a sub-template for each of the elements. This pattern has been implemented as a single method that accepts an array and renders a partial for each one of the elements in the array.
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md
index 493fd526fb..bbe1b0decc 100644
--- a/guides/source/active_record_querying.md
+++ b/guides/source/active_record_querying.md
@@ -50,7 +50,7 @@ class Role < ApplicationRecord
 end
 ```
 
-Active Record will perform queries on the database for you and is compatible with most database systems, including MySQL, MariaDB, PostgreSQL and SQLite. Regardless of which database system you're using, the Active Record method format will always be the same.
+Active Record will perform queries on the database for you and is compatible with most database systems, including MySQL, MariaDB, PostgreSQL, and SQLite. Regardless of which database system you're using, the Active Record method format will always be the same.
 
 Retrieving Objects from the Database
 ------------------------------------
@@ -1020,7 +1020,7 @@ Author.joins("INNER JOIN posts ON posts.author_id = authors.id AND posts.publish
 This will result in the following SQL:
 
 ```sql
-SELECT clients.* FROM clients INNER JOIN posts ON posts.author_id = authors.id AND posts.published = 't'
+SELECT authors.* FROM authors INNER JOIN posts ON posts.author_id = authors.id AND posts.published = 't'
 ```
 
 #### Using Array/Hash of Named Associations
diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index aba4c6a97b..60a6c37f82 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -2036,7 +2036,7 @@ Addition only assumes the elements respond to `+`:
 ```ruby
 [[1, 2], [2, 3], [3, 4]].sum    # => [1, 2, 2, 3, 3, 4]
 %w(foo bar baz).sum             # => "foobarbaz"
-{a: 1, b: 2, c: 3}.sum # => [:b, 2, :c, 3, :a, 1]
+{a: 1, b: 2, c: 3}.sum          # => [:b, 2, :c, 3, :a, 1]
 ```
 
 The sum of an empty collection is zero by default, but this is customizable:
diff --git a/guides/source/association_basics.md b/guides/source/association_basics.md
index 2e682b6951..3837cda553 100644
--- a/guides/source/association_basics.md
+++ b/guides/source/association_basics.md
@@ -387,7 +387,7 @@ The corresponding migration might look like this:
 class CreateSuppliers < ActiveRecord::Migration[5.0]
   def change
     create_table :suppliers do |t|
-      t.string  :name
+      t.string :name
       t.timestamps
     end
 
@@ -550,8 +550,8 @@ But what if you want to reload the cache, because data might have been changed b
 ```ruby
 author.books                 # retrieves books from the database
 author.books.size            # uses the cached copy of books
-author.books.reload.empty?    # discards the cached copy of books
-                                # and goes back to the database
+author.books.reload.empty?   # discards the cached copy of books
+                             # and goes back to the database
 ```
 
 ### Avoiding Name Collisions
@@ -1841,7 +1841,7 @@ article   = Article.create(name: 'a1')
 person.articles << article
 person.articles << article
 person.articles.inspect # => [#<Article id: 5, name: "a1">, #<Article id: 5, name: "a1">]
-Reading.all.inspect  # => [#<Reading id: 12, person_id: 5, article_id: 5>, #<Reading id: 13, person_id: 5, article_id: 5>]
+Reading.all.inspect     # => [#<Reading id: 12, person_id: 5, article_id: 5>, #<Reading id: 13, person_id: 5, article_id: 5>]
 ```
 
 In the above case there are two readings and `person.articles` brings out both of
@@ -1860,7 +1860,7 @@ article   = Article.create(name: 'a1')
 person.articles << article
 person.articles << article
 person.articles.inspect # => [#<Article id: 7, name: "a1">]
-Reading.all.inspect  # => [#<Reading id: 16, person_id: 7, article_id: 7>, #<Reading id: 17, person_id: 7, article_id: 7>]
+Reading.all.inspect     # => [#<Reading id: 16, person_id: 7, article_id: 7>, #<Reading id: 17, person_id: 7, article_id: 7>]
 ```
 
 In the above case there are still two readings. However `person.articles` shows
diff --git a/guides/source/caching_with_rails.md b/guides/source/caching_with_rails.md
index a1b0029c47..fd7626250c 100644
--- a/guides/source/caching_with_rails.md
+++ b/guides/source/caching_with_rails.md
@@ -381,7 +381,7 @@ config.cache_store = :memory_store, { size: 64.megabytes }
 ```
 
 If you're running multiple Ruby on Rails server processes (which is the case
-if you're using mongrel_cluster or Phusion Passenger), then your Rails server
+if you're using Phusion Passenger or puma clustered mode), then your Rails server
 process instances won't be able to share cache data with each other. This cache
 store is not appropriate for large application deployments. However, it can
 work well for small, low traffic sites with only a couple of server processes,
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index a115683134..fbf3c27957 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -71,7 +71,7 @@ These configuration methods are to be called on a `Rails::Railtie` object, such
 * `config.beginning_of_week` sets the default beginning of week for the
 application. Accepts a valid week day symbol (e.g. `:monday`).
 
-* `config.cache_store` configures which cache store to use for Rails caching. Options include one of the symbols `:memory_store`, `:file_store`, `:mem_cache_store`, `:null_store`, or an object that implements the cache API. Defaults to `:file_store` if the directory `tmp/cache` exists, and to `:memory_store` otherwise.
+* `config.cache_store` configures which cache store to use for Rails caching. Options include one of the symbols `:memory_store`, `:file_store`, `:mem_cache_store`, `:null_store`, or an object that implements the cache API. Defaults to `:file_store`.
 
 * `config.colorize_logging` specifies whether or not to use ANSI color codes when logging information. Defaults to `true`.
 
@@ -131,7 +131,7 @@ defaults to `:debug` for all environments. The available log levels are: `:debug
 
     mylogger           = MyLogger.new(STDOUT)
     mylogger.formatter = config.log_formatter
-    config.logger = ActiveSupport::TaggedLogging.new(mylogger)
+    config.logger      = ActiveSupport::TaggedLogging.new(mylogger)
     ```
 
 * `config.middleware` allows you to configure the application's middleware. This is covered in depth in the [Configuring Middleware](#configuring-middleware) section below.
@@ -1198,7 +1198,7 @@ development:
   timeout: 5000
 ```
 
-Since the connection pooling is handled inside of Active Record by default, all application servers (Thin, mongrel, Unicorn etc.) should behave the same. The database connection pool is initially empty. As demand for connections increases it will create them until it reaches the connection pool limit.
+Since the connection pooling is handled inside of Active Record by default, all application servers (Thin, Puma, Unicorn etc.) should behave the same. The database connection pool is initially empty. As demand for connections increases it will create them until it reaches the connection pool limit.
 
 Any one request will check out a connection the first time it requires access to the database. At the end of the request it will check the connection back in. This means that the additional connection slot will be available again for the next request in the queue.
 
diff --git a/guides/source/contributing_to_ruby_on_rails.md b/guides/source/contributing_to_ruby_on_rails.md
index 5df16e68c9..4f938f5deb 100644
--- a/guides/source/contributing_to_ruby_on_rails.md
+++ b/guides/source/contributing_to_ruby_on_rails.md
@@ -40,6 +40,7 @@ Then, don't get your hopes up! Unless you have a "Code Red, Mission Critical, th
 Having a way to reproduce your issue will be very helpful for others to help confirm, investigate and ultimately fix your issue. You can do this by providing an executable test case. To make this process easier, we have prepared several bug report templates for you to use as a starting point:
 
 * Template for Active Record (models, database) issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_master.rb)
+* Template for testing Active Record (migration) issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_migrations_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_migrations_master.rb)
 * Template for Action Pack (controllers, routing) issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/action_controller_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/action_controller_master.rb)
 * Template for Active Job issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_job_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_job_master.rb)
 * Generic template for other issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/generic_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/generic_master.rb)
diff --git a/guides/source/engines.md b/guides/source/engines.md
index d6118c014f..0020112a1c 100644
--- a/guides/source/engines.md
+++ b/guides/source/engines.md
@@ -46,7 +46,7 @@ see how to hook it into an application.
 
 Engines can also be isolated from their host applications. This means that an
 application is able to have a path provided by a routing helper such as
-`articles_path` and use an engine also that provides a path also called
+`articles_path` and use an engine that also provides a path also called
 `articles_path`, and the two would not clash. Along with this, controllers, models
 and table names are also namespaced. You'll see how to do this later in this
 guide.
@@ -184,7 +184,7 @@ end
 By inheriting from the `Rails::Engine` class, this gem notifies Rails that
 there's an engine at the specified path, and will correctly mount the engine
 inside the application, performing tasks such as adding the `app` directory of
-the engine to the load path for models, mailers, controllers and views.
+the engine to the load path for models, mailers, controllers, and views.
 
 The `isolate_namespace` method here deserves special notice. This call is
 responsible for isolating the controllers, models, routes and other things into
diff --git a/guides/source/initialization.md b/guides/source/initialization.md
index a2eec03eba..57ed35d0d8 100644
--- a/guides/source/initialization.md
+++ b/guides/source/initialization.md
@@ -318,7 +318,7 @@ def parse!(args)
   args, options = args.dup, {}
 
   opt_parser = OptionParser.new do |opts|
-    opts.banner = "Usage: rails server [mongrel, thin, etc] [options]"
+    opts.banner = "Usage: rails server [puma, thin, etc] [options]"
     opts.on("-p", "--port=port", Integer,
             "Runs Rails on the specified port.", "Default: 3000") { |v| options[:Port] = v }
   ...
@@ -663,7 +663,7 @@ DEFAULT_OPTIONS = {
 }
 
 def self.run(app, options = {})
-  options  = DEFAULT_OPTIONS.merge(options)
+  options = DEFAULT_OPTIONS.merge(options)
 
   if options[:Verbose]
     app = Rack::CommonLogger.new(app, STDOUT)
diff --git a/guides/source/layouts_and_rendering.md b/guides/source/layouts_and_rendering.md
index 2722789c49..7e4ec5ba7e 100644
--- a/guides/source/layouts_and_rendering.md
+++ b/guides/source/layouts_and_rendering.md
@@ -630,6 +630,8 @@ to use in this case.
 redirect_back(fallback_location: root_path)
 ```
 
+NOTE: `redirect_to` and `redirect_back` do not halt and return immediately from method execution, but simply set HTTP responses. Statements occurring after them in a method will be executed. You can halt by an explicit `return` or some other halting mechanism, if needed.
+
 #### Getting a Different Redirect Status Code
 
 Rails uses HTTP status code 302, a temporary redirect, when you call `redirect_to`. If you'd like to use a different status code, perhaps 301, a permanent redirect, you can use the `:status` option:
@@ -749,7 +751,7 @@ When Rails renders a view as a response, it does so by combining the view with t
 
 ### Asset Tag Helpers
 
-Asset tag helpers provide methods for generating HTML that link views to feeds, JavaScript, stylesheets, images, videos and audios. There are six asset tag helpers available in Rails:
+Asset tag helpers provide methods for generating HTML that link views to feeds, JavaScript, stylesheets, images, videos, and audios. There are six asset tag helpers available in Rails:
 
 * `auto_discovery_link_tag`
 * `javascript_include_tag`
diff --git a/guides/source/security.md b/guides/source/security.md
index 5c3d465220..aea9728c10 100644
--- a/guides/source/security.md
+++ b/guides/source/security.md
@@ -131,7 +131,7 @@ It works like this:
 * The user takes the cookie from the first step (which they previously copied) and replaces the current cookie in the browser.
 * The user has their original credit back.
 
-Including a nonce (a random value) in the session solves replay attacks. A nonce is valid only once, and the server has to keep track of all the valid nonces. It gets even more complicated if you have several application servers (mongrels). Storing nonces in a database table would defeat the entire purpose of CookieStore (avoiding accessing the database).
+Including a nonce (a random value) in the session solves replay attacks. A nonce is valid only once, and the server has to keep track of all the valid nonces. It gets even more complicated if you have several application servers. Storing nonces in a database table would defeat the entire purpose of CookieStore (avoiding accessing the database).
 
 The best _solution against it is not to store this kind of data in a session, but in the database_. In this case store the credit in the database and the logged_in_user_id in the session.
 
diff --git a/guides/source/testing.md b/guides/source/testing.md
index 8f9246dea2..0ac5121b12 100644
--- a/guides/source/testing.md
+++ b/guides/source/testing.md
@@ -761,8 +761,8 @@ and also ensuring that the right response body has been generated.
 
 The `get` method kicks off the web request and populates the results into the `@response`. It can accept up to 6 arguments:
 
-* The action of the controller you are requesting.
-  This can be in the form of a string or a route (i.e. `articles_url`).
+* The URI of the controller action you are requesting.
+  This can be in the form of a string or a route helper (e.g. `articles_url`).
 * `params`: option with a hash of request parameters to pass into the action
   (e.g. query string parameters or article variables).
 * `headers`: for setting the headers that will be passed with the request.
@@ -775,13 +775,13 @@ All of these keyword arguments are optional.
 Example: Calling the `:show` action, passing an `id` of 12 as the `params` and setting `HTTP_REFERER` header:
 
 ```ruby
-get :show, params: { id: 12 }, headers: { "HTTP_REFERER" => "http://example.com/home" }
+get article_url, params: { id: 12 }, headers: { "HTTP_REFERER" => "http://example.com/home" }
 ```
 
 Another example: Calling the `:update` action, passing an `id` of 12 as the `params` as an Ajax request.
 
 ```ruby
-patch update_url, params: { id: 12 }, xhr: true
+patch article_url, params: { id: 12 }, xhr: true
 ```
 
 NOTE: If you try running `test_should_create_article` test from `articles_controller_test.rb` it will fail on account of the newly added model level validation and rightly so.
@@ -1317,8 +1317,8 @@ end
 This test is pretty simple and only asserts that the job get the work done
 as expected.
 
-By default, `ActiveJob::TestCase` will set the queue adapter to `:async` so that
-your jobs are performed in an async fashion. It will also ensure that all previously performed
+By default, `ActiveJob::TestCase` will set the queue adapter to `:test` so that
+your jobs are performed inline. It will also ensure that all previously performed
 and enqueued jobs are cleared before any test run so you can safely assume that
 no jobs have already been executed in the scope of each test.