Merge branch 'master' into feature/reselect-method

7 files changed, 74 insertions, 38 deletions

diff --git a/guides/source/association_basics.md b/guides/source/association_basics.md
index b0a905c754..78a1f47407 100644
--- a/guides/source/association_basics.md
+++ b/guides/source/association_basics.md
@@ -868,7 +868,7 @@ While Rails uses intelligent defaults that will work well in most situations, th
 
 ```ruby
 class Book < ApplicationRecord
-  belongs_to :author, dependent: :destroy,
+  belongs_to :author, touch: :books_updated_at,
     counter_cache: true
 end
 ```
@@ -1048,8 +1048,7 @@ There may be times when you wish to customize the query used by `belongs_to`. Su
 
 ```ruby
 class Book < ApplicationRecord
-  belongs_to :author, -> { where active: true },
-                        dependent: :destroy
+  belongs_to :author, -> { where active: true }
 end
 ```
 
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index 812565b207..61bb35cf93 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -200,8 +200,6 @@ The full set of methods that can be used in this block are as follows:
 * `helper` defines whether or not to generate helpers. Defaults to `true`.
 * `integration_tool` defines which integration tool to use to generate integration tests. Defaults to `:test_unit`.
 * `system_tests` defines which integration tool to use to generate system tests. Defaults to `:test_unit`.
-* `javascripts` turns on the hook for JavaScript files in generators. Used in Rails for when the `scaffold` generator is run. Defaults to `true`.
-* `javascript_engine` configures the engine to be used (for eg. coffee) when generating assets. Defaults to `:js`.
 * `orm` defines which orm to use. Defaults to `false` and will use Active Record by default.
 * `resource_controller` defines which generator to use for generating a controller when using `rails generate resource`. Defaults to `:controller`.
 * `resource_route` defines whether a resource route definition should be generated
diff --git a/guides/source/debugging_rails_applications.md b/guides/source/debugging_rails_applications.md
index 88d205e1ab..7f7766e7d7 100644
--- a/guides/source/debugging_rails_applications.md
+++ b/guides/source/debugging_rails_applications.md
@@ -186,14 +186,17 @@ end
 Here's an example of the log generated when this controller action is executed:
 
 ```
-Started POST "/articles" for 127.0.0.1 at 2017-08-20 20:53:10 +0900
+Started POST "/articles" for 127.0.0.1 at 2018-10-18 20:09:23 -0400
 Processing by ArticlesController#create as HTML
-  Parameters: {"utf8"=>"✓", "authenticity_token"=>"xhuIbSBFytHCE1agHgvrlKnSVIOGD6jltW2tO+P6a/ACjQ3igjpV4OdbsZjIhC98QizWH9YdKokrqxBCJrtoqQ==", "article"=>{"title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs!!!", "published"=>"0"}, "commit"=>"Create Article"}
-New article: {"id"=>nil, "title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs!!!", "published"=>false, "created_at"=>nil, "updated_at"=>nil}
+  Parameters: {"utf8"=>"✓", "authenticity_token"=>"XLveDrKzF1SwaiNRPTaMtkrsTzedtebPPkmxEFIU0ordLjICSnXsSNfrdMa4ccyBjuGwnnEiQhEoMN6H1Gtz3A==", "article"=>{"title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs.", "published"=>"0"}, "commit"=>"Create Article"}
+New article: {"id"=>nil, "title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs.", "published"=>false, "created_at"=>nil, "updated_at"=>nil}
 Article should be valid: true
-   (0.1ms)  BEGIN
-  SQL (0.4ms)  INSERT INTO "articles" ("title", "body", "published", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id"  [["title", "Debugging Rails"], ["body", "I'm learning how to print in logs!!!"], ["published", "f"], ["created_at", "2017-08-20 11:53:10.010435"], ["updated_at", "2017-08-20 11:53:10.010435"]]
-   (0.3ms)  COMMIT
+   (0.0ms)  begin transaction
+  ↳ app/controllers/articles_controller.rb:31
+  Article Create (0.5ms)  INSERT INTO "articles" ("title", "body", "published", "created_at", "updated_at") VALUES (?, ?, ?, ?, ?)  [["title", "Debugging Rails"], ["body", "I'm learning how to print in logs."], ["published", 0], ["created_at", "2018-10-19 00:09:23.216549"], ["updated_at", "2018-10-19 00:09:23.216549"]]
+  ↳ app/controllers/articles_controller.rb:31
+   (2.3ms)  commit transaction
+  ↳ app/controllers/articles_controller.rb:31
 The article was saved and now the user is going to be redirected...
 Redirected to http://localhost:3000/articles/1
 Completed 302 Found in 4ms (ActiveRecord: 0.8ms)
@@ -201,6 +204,40 @@ Completed 302 Found in 4ms (ActiveRecord: 0.8ms)
 
 Adding extra logging like this makes it easy to search for unexpected or unusual behavior in your logs. If you add extra logging, be sure to make sensible use of log levels to avoid filling your production logs with useless trivia.
 
+### Verbose Query Logs
+
+When looking at database query output in logs, it may not be immediately clear why multiple database queries are triggered when a single method is called:
+
+```
+irb(main):001:0> Article.pamplemousse
+  Article Load (0.4ms)  SELECT "articles".* FROM "articles"
+  Comment Load (0.2ms)  SELECT "comments".* FROM "comments" WHERE "comments"."article_id" = ?  [["article_id", 1]]
+  Comment Load (0.1ms)  SELECT "comments".* FROM "comments" WHERE "comments"."article_id" = ?  [["article_id", 2]]
+  Comment Load (0.1ms)  SELECT "comments".* FROM "comments" WHERE "comments"."article_id" = ?  [["article_id", 3]]
+=> #<Comment id: 2, author: "1", body: "Well, actually...", article_id: 1, created_at: "2018-10-19 00:56:10", updated_at: "2018-10-19 00:56:10">
+```
+
+After running `ActiveRecord::Base.verbose_query_logs = true` in the `rails console` session to enable verbose query logs and running the method again, it becomes obvious what single line of code is generating all these discrete database calls:
+
+```
+irb(main):003:0> Article.pamplemousse
+  Article Load (0.2ms)  SELECT "articles".* FROM "articles"
+  ↳ app/models/article.rb:5
+  Comment Load (0.1ms)  SELECT "comments".* FROM "comments" WHERE "comments"."article_id" = ?  [["article_id", 1]]
+  ↳ app/models/article.rb:6
+  Comment Load (0.1ms)  SELECT "comments".* FROM "comments" WHERE "comments"."article_id" = ?  [["article_id", 2]]
+  ↳ app/models/article.rb:6
+  Comment Load (0.1ms)  SELECT "comments".* FROM "comments" WHERE "comments"."article_id" = ?  [["article_id", 3]]
+  ↳ app/models/article.rb:6
+=> #<Comment id: 2, author: "1", body: "Well, actually...", article_id: 1, created_at: "2018-10-19 00:56:10", updated_at: "2018-10-19 00:56:10">
+```
+
+Below each database statement you can see arrows pointing to the specific source filename (and line number) of the method that resulted in a database call. This can help you identity and address performance problems caused by N+1 queries: single database queries that generates multiple additional queries.
+
+Verbose query logs are enabled by default in the development environment logs after Rails 5.2.
+
+WARNING: We recommend against using this setting in production environments. It relies on Ruby's `Kernel#caller` method which tends to allocate a lot of memory in order to generate stacktraces of method calls.
+
 ### Tagged Logging
 
 When running multi-user, multi-account applications, it's often useful
diff --git a/guides/source/documents.yaml b/guides/source/documents.yaml
index 8f2312458d..551179c523 100644
--- a/guides/source/documents.yaml
+++ b/guides/source/documents.yaml
@@ -173,7 +173,7 @@
       description: This guide describes the considerations needed and tools available when working directly with concurrency in a Rails application.
       work_in_progress: true
 -
-  name: Contributing to Ruby on Rails
+  name: Contributions
   documents:
     -
       name: Contributing to Ruby on Rails
@@ -184,14 +184,14 @@
       url: api_documentation_guidelines.html
       description: This guide documents the Ruby on Rails API documentation guidelines.
     -
-      name: Ruby on Rails Guides Guidelines
+      name: Guides Guidelines
       url: ruby_on_rails_guides_guidelines.html
       description: This guide documents the Ruby on Rails guides guidelines.
 -
-  name: Maintenance Policy
+  name: Policies
   documents:
     -
-      name: Maintenance Policy for Ruby on Rails
+      name: Maintenance Policy
       url: maintenance_policy.html
       description: What versions of Ruby on Rails are currently supported, and when to expect new versions.
 -
@@ -202,51 +202,51 @@
       url: upgrading_ruby_on_rails.html
       description: This guide helps in upgrading applications to latest Ruby on Rails versions.
     -
-      name: Ruby on Rails 6.0 Release Notes
+      name: 6.0 Release Notes
       work_in_progress: true
       url: 6_0_release_notes.html
       description: Release notes for Rails 6.0.
     -
-      name: Ruby on Rails 5.2 Release Notes
+      name: 5.2 Release Notes
       url: 5_2_release_notes.html
       description: Release notes for Rails 5.2.
     -
-      name: Ruby on Rails 5.1 Release Notes
+      name: 5.1 Release Notes
       url: 5_1_release_notes.html
       description: Release notes for Rails 5.1.
     -
-      name: Ruby on Rails 5.0 Release Notes
+      name: 5.0 Release Notes
       url: 5_0_release_notes.html
       description: Release notes for Rails 5.0.
     -
-      name: Ruby on Rails 4.2 Release Notes
+      name: 4.2 Release Notes
       url: 4_2_release_notes.html
       description: Release notes for Rails 4.2.
     -
-      name: Ruby on Rails 4.1 Release Notes
+      name: 4.1 Release Notes
       url: 4_1_release_notes.html
       description: Release notes for Rails 4.1.
     -
-      name: Ruby on Rails 4.0 Release Notes
+      name: 4.0 Release Notes
       url: 4_0_release_notes.html
       description: Release notes for Rails 4.0.
     -
-      name: Ruby on Rails 3.2 Release Notes
+      name: 3.2 Release Notes
       url: 3_2_release_notes.html
       description: Release notes for Rails 3.2.
     -
-      name: Ruby on Rails 3.1 Release Notes
+      name: 3.1 Release Notes
       url: 3_1_release_notes.html
       description: Release notes for Rails 3.1.
     -
-      name: Ruby on Rails 3.0 Release Notes
+      name: 3.0 Release Notes
       url: 3_0_release_notes.html
       description: Release notes for Rails 3.0.
     -
-      name: Ruby on Rails 2.3 Release Notes
+      name: 2.3 Release Notes
       url: 2_3_release_notes.html
       description: Release notes for Rails 2.3.
     -
-      name: Ruby on Rails 2.2 Release Notes
+      name: 2.2 Release Notes
       url: 2_2_release_notes.html
       description: Release notes for Rails 2.2.
diff --git a/guides/source/i18n.md b/guides/source/i18n.md
index 78e5f27448..eba71eec60 100644
--- a/guides/source/i18n.md
+++ b/guides/source/i18n.md
@@ -116,7 +116,7 @@ NOTE: The backend lazy-loads these translations when a translation is looked up
 You can change the default locale as well as configure the translations load paths in `config/application.rb` as follows:
 
 ```ruby
-  config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
+  config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}')]
   config.i18n.default_locale = :de
 ```
 
@@ -135,6 +135,8 @@ I18n.available_locales = [:en, :pt]
 I18n.default_locale = :pt
 ```
 
+Note that appending directly to `I18n.load_paths` instead of to the application's configured i18n will _not_ override translations from external gems.
+
 ### Managing the Locale across Requests
 
 The default locale is used for all translations unless `I18n.locale` is explicitly set.
diff --git a/guides/source/layout.html.erb b/guides/source/layout.html.erb
index dd9175e312..1f42d72756 100644
--- a/guides/source/layout.html.erb
+++ b/guides/source/layout.html.erb
@@ -45,16 +45,16 @@
           <a href="index.html" id="guidesMenu" class="guides-index-item nav-item">Guides Index</a>
           <div id="guides" class="clearfix" style="display: none;">
             <hr />
-            <% ['L', 'R'].each do |position| %>
-              <dl class="<%= position %>">
-              <% docs_for_menu(position).each do |section| %>
-                <dt><%= section['name'] %></dt>
-                <% finished_documents(section['documents']).each do |document| %>
-                <dd><a href="<%= document['url'] %>"><%= document['name'] %></a></dd>
-                <% end %>
+            <div class="guides-section-container">
+              <% documents_by_section.each do |section| %>
+                <div class="guides-section">
+                  <dt><%= section['name'] %></dt>
+                  <% finished_documents(section['documents']).each do |document| %>
+                  <dd><a href="<%= document['url'] %>"><%= document['name'] %></a></dd>
+                  <% end %>
+                </div>
               <% end %>
-              </dl>
-            <% end %>
+            </div>
           </div>
         </li>
         <li><a class="nav-item" href="contributing_to_ruby_on_rails.html">Contribute</a></li>
diff --git a/guides/source/testing.md b/guides/source/testing.md
index 9de2229672..8c21ccfba6 100644
--- a/guides/source/testing.md
+++ b/guides/source/testing.md
@@ -1562,7 +1562,7 @@ class UserMailerTest < ActionMailer::TestCase
 end
 ```
 
-In the test we send the email and store the returned object in the `email`
+In the test we create the email and store the returned object in the `email`
 variable. We then ensure that it was sent (the first assert), then, in the
 second batch of assertions, we ensure that the email does indeed contain what we
 expect. The helper `read_fixture` is used to read in the content from this file.