From 91fc1beed7b9eac6b577a4598aa98226175b8347 Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Tue, 9 May 2023 13:47:53 +0900
Subject: [PATCH] [Fix #11862] Fix an incorrect autocorrect for
 `Style/GuardClause`

Fixes #11862.

This PR fixes an incorrect autocorrect for `Style/GuardClause`
when using `raise` in `else` branch in a one-liner with `then`.
---
 ...n_incorrect_autocorrect_for_style_guard_clause.md |  1 +
 lib/rubocop/cop/style/guard_clause.rb                |  2 ++
 spec/rubocop/cop/style/guard_clause_spec.rb          | 12 ++++++++++++
 3 files changed, 15 insertions(+)
 create mode 100644 changelog/fix_an_incorrect_autocorrect_for_style_guard_clause.md

diff --git a/changelog/fix_an_incorrect_autocorrect_for_style_guard_clause.md b/changelog/fix_an_incorrect_autocorrect_for_style_guard_clause.md
new file mode 100644
index 00000000000..885708c1e1a
--- /dev/null
+++ b/changelog/fix_an_incorrect_autocorrect_for_style_guard_clause.md
@@ -0,0 +1 @@
+* [#11862](https://github.com/rubocop/rubocop/issues/11862): Fix an incorrect autocorrect for `Style/GuardClause` when using `raise` in `else` branch in a one-liner with `then`. ([@koic][])
diff --git a/lib/rubocop/cop/style/guard_clause.rb b/lib/rubocop/cop/style/guard_clause.rb
index c637682a384..ab380992a4f 100644
--- a/lib/rubocop/cop/style/guard_clause.rb
+++ b/lib/rubocop/cop/style/guard_clause.rb
@@ -187,6 +187,8 @@ def autocorrect(corrector, node, condition, replacement, guard)
           if_branch = node.if_branch
           else_branch = node.else_branch
 
+          corrector.replace(node.loc.begin, "\n") if node.loc.begin&.is?('then')
+
           if if_branch&.send_type? && heredoc?(if_branch.last_argument)
             autocorrect_heredoc_argument(corrector, node, if_branch, else_branch, guard)
           elsif else_branch&.send_type? && heredoc?(else_branch.last_argument)
diff --git a/spec/rubocop/cop/style/guard_clause_spec.rb b/spec/rubocop/cop/style/guard_clause_spec.rb
index a14ef48f40b..4b317e71a01 100644
--- a/spec/rubocop/cop/style/guard_clause_spec.rb
+++ b/spec/rubocop/cop/style/guard_clause_spec.rb
@@ -165,6 +165,18 @@ def func
     expect_no_corrections
   end
 
+  it 'registers an offense when using `raise` in `else` branch in a one-liner with `then`' do
+    expect_offense(<<~RUBY)
+      if something then work else raise('message') end
+      ^^ Use a guard clause (`raise('message') unless something`) instead of wrapping the code inside a conditional expression.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      raise('message') unless something#{trailing_whitespace}
+       work#{trailing_whitespace * 3}
+    RUBY
+  end
+
   it 'registers an offense when using `and return` in `then` branch' do
     expect_offense(<<~RUBY)
       def func