Support auto-correction for Rails/Output

This PR supports auto-correction for `Rails/Output`.

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### New features
+
+* [#521](https://github.com/rubocop/rubocop-rails/pull/521): Support auto-correction for `Rails/Output`. ([@koic][])
+
 ## 2.11.3 (2021-07-11)
 
 ### Bug fixes

docs/modules/ROOT/pages/cops_rails.adoc

@@ -2747,7 +2747,7 @@ scope :chronological, -> { order(created_at: :asc) }
 
 | Enabled
 | Yes
-| No
+| Yes
 | 0.15
 | 0.19
 |===

lib/rubocop/cop/rails/output.rb

@@ -14,6 +14,9 @@ module Rails
       #   # good
       #   Rails.logger.debug 'A debug message'
       class Output < Base
+        include RangeHelp
+        extend AutoCorrector
+
         MSG = 'Do not write to stdout. ' \
               "Use Rails's logger if you want to log."
         RESTRICT_ON_SEND = %i[
@@ -35,17 +38,28 @@ class Output < Base
         PATTERN
 
         def on_send(node)
-          return unless (output?(node) || io_output?(node)) &&
-                        node.arguments?
+          return unless (output?(node) || io_output?(node)) && node.arguments?
+
+          range = offense_range(node)
 
-          add_offense(node.loc.selector)
+          add_offense(range) do |corrector|
+            corrector.replace(range, 'Rails.logger.debug')
+          end
         end
 
         private
 
         def match_gvar?(sym)
           %i[$stdout $stderr].include?(sym)
         end
+
+        def offense_range(node)
+          if node.receiver
+            range_between(node.loc.expression.begin_pos, node.loc.selector.end_pos)
+          else
+            node.loc.selector
+          end
+        end
       end
     end
   end

spec/rubocop/cop/rails/output_spec.rb

@@ -1,22 +1,80 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::Output, :config do
-  it 'registers an offense for methods without a receiver' do
+  it 'registers and corrects an offense for using `p` method without a receiver' do
     expect_offense(<<~RUBY)
       p "edmond dantes"
       ^ Do not write to stdout. Use Rails's logger if you want to log.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      Rails.logger.debug "edmond dantes"
+    RUBY
+  end
+
+  it 'registers and corrects an offense for using `puts` method without a receiver' do
+    expect_offense(<<~RUBY)
       puts "sinbad"
       ^^^^ Do not write to stdout. Use Rails's logger if you want to log.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      Rails.logger.debug "sinbad"
+    RUBY
+  end
+
+  it 'registers and corrects an offense for using `print` method without a receiver' do
+    expect_offense(<<~RUBY)
       print "abbe busoni"
       ^^^^^ Do not write to stdout. Use Rails's logger if you want to log.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      Rails.logger.debug "abbe busoni"
+    RUBY
+  end
+
+  it 'registers and corrects an offense for using `pp` method without a receiver' do
+    expect_offense(<<~RUBY)
       pp "monte cristo"
       ^^ Do not write to stdout. Use Rails's logger if you want to log.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      Rails.logger.debug "monte cristo"
+    RUBY
+  end
+
+  it 'registers and corrects an offense for using `$stdout` method without a receiver' do
+    expect_offense(<<~RUBY)
       $stdout.write "lord wilmore"
-              ^^^^^ Do not write to stdout. Use Rails's logger if you want to log.
+      ^^^^^^^^^^^^^ Do not write to stdout. Use Rails's logger if you want to log.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      Rails.logger.debug "lord wilmore"
+    RUBY
+  end
+
+  it 'registers and corrects an offense for using `syswrite` method without a receiver' do
+    expect_offense(<<~RUBY)
       $stderr.syswrite "faria"
-              ^^^^^^^^ Do not write to stdout. Use Rails's logger if you want to log.
+      ^^^^^^^^^^^^^^^^ Do not write to stdout. Use Rails's logger if you want to log.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      Rails.logger.debug "faria"
+    RUBY
+  end
+
+  it 'registers and corrects an offense for using `write` method without a receiver' do
+    expect_offense(<<~RUBY)
       STDOUT.write "bertuccio"
-             ^^^^^ Do not write to stdout. Use Rails's logger if you want to log.
+      ^^^^^^^^^^^^ Do not write to stdout. Use Rails's logger if you want to log.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      Rails.logger.debug "bertuccio"
     RUBY
   end