From ce67bd8b40153bdffd980bfd386d58d46af20799 Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Sat, 20 Jun 2020 07:07:26 +0900
Subject: [PATCH] Support autocorrection for `Lint/RegexpAsCondition`

This PR supports autocorrection for `Lint/RegexpAsCondition`.
---
 CHANGELOG.md                                      | 1 +
 config/default.yml                                | 1 +
 docs/modules/ROOT/pages/cops_lint.adoc            | 4 ++--
 lib/rubocop/cop/lint/regexp_as_condition.rb       | 6 ++++++
 spec/rubocop/cop/lint/regexp_as_condition_spec.rb | 7 ++++++-
 5 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e37b805f504..f90245a5b18 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 * [#8148](https://github.com/rubocop-hq/rubocop/pull/8148): Support autocorrection for `Style/MultilineTernaryOperator`. ([@koic][])
 * [#8151](https://github.com/rubocop-hq/rubocop/pull/8151): Support autocorrection for `Style/NestedTernaryOperator`. ([@koic][])
 * [#8142](https://github.com/rubocop-hq/rubocop/pull/8142): Add `Lint/ConstantResolution` cop. ([@robotdana][])
+* [#8170](https://github.com/rubocop-hq/rubocop/pull/8170): Support autocorrection for `Lint/RegexpAsCondition`. ([@koic][])
 
 ### Bug fixes
 
diff --git a/config/default.yml b/config/default.yml
index ddfbaa8eb22..19c9ffa270f 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -1677,6 +1677,7 @@ Lint/RegexpAsCondition:
                  The regexp literal matches `$_` implicitly.
   Enabled: true
   VersionAdded: '0.51'
+  VersionChanged: '0.86'
 
 Lint/RequireParentheses:
   Description: >-
diff --git a/docs/modules/ROOT/pages/cops_lint.adoc b/docs/modules/ROOT/pages/cops_lint.adoc
index 925ec93c28b..fb6601b1781 100644
--- a/docs/modules/ROOT/pages/cops_lint.adoc
+++ b/docs/modules/ROOT/pages/cops_lint.adoc
@@ -2524,9 +2524,9 @@ end
 
 | Enabled
 | Yes
-| No
+| Yes
 | 0.51
-| -
+| 0.86
 |===
 
 This cop checks for regexp literals used as `match-current-line`.
diff --git a/lib/rubocop/cop/lint/regexp_as_condition.rb b/lib/rubocop/cop/lint/regexp_as_condition.rb
index 3a06a929948..9ffdbd403ca 100644
--- a/lib/rubocop/cop/lint/regexp_as_condition.rb
+++ b/lib/rubocop/cop/lint/regexp_as_condition.rb
@@ -23,6 +23,12 @@ class RegexpAsCondition < Cop
         def on_match_current_line(node)
           add_offense(node)
         end
+
+        def autocorrect(node)
+          lambda do |corrector|
+            corrector.replace(node, "#{node.source} =~ $_")
+          end
+        end
       end
     end
   end
diff --git a/spec/rubocop/cop/lint/regexp_as_condition_spec.rb b/spec/rubocop/cop/lint/regexp_as_condition_spec.rb
index cda56d79a92..3a8d15abd5d 100644
--- a/spec/rubocop/cop/lint/regexp_as_condition_spec.rb
+++ b/spec/rubocop/cop/lint/regexp_as_condition_spec.rb
@@ -5,12 +5,17 @@
 
   let(:config) { RuboCop::Config.new }
 
-  it 'registers an offense for a regexp literal in `if` condition' do
+  it 'registers an offense and corrects for a regexp literal in `if` condition' do
     expect_offense(<<~RUBY)
       if /foo/
          ^^^^^ Do not use regexp literal as a condition. The regexp literal matches `$_` implicitly.
       end
     RUBY
+
+    expect_correction(<<~RUBY)
+      if /foo/ =~ $_
+      end
+    RUBY
   end
 
   it 'does not register an offense for a regexp literal outside conditions' do