From dd96eb03e4a39dee719f672c8497ad01432c383d Mon Sep 17 00:00:00 2001
From: SAY-5 <say.apm35@gmail.com>
Date: Sat, 23 May 2026 21:57:46 -0700
Subject: [PATCH] feat(style/heredoc_escape): add autocorrection

---
 spec/ameba/rule/style/heredoc_escape_spec.cr | 32 +++++++++++++++++---
 src/ameba/rule/style/heredoc_escape.cr       | 10 ++++--
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/spec/ameba/rule/style/heredoc_escape_spec.cr b/spec/ameba/rule/style/heredoc_escape_spec.cr
index a21db75f5..81a0e92b7 100644
--- a/spec/ameba/rule/style/heredoc_escape_spec.cr
+++ b/spec/ameba/rule/style/heredoc_escape_spec.cr
@@ -45,21 +45,33 @@ module Ameba::Rule::Style
     end
 
     it "fails if a heredoc contains escaped interpolation" do
-      expect_issue subject, <<-'CRYSTAL'
+      source = expect_issue subject, <<-'CRYSTAL'
         <<-HEREDOC
         # ^^^^^^^^ error: Use an escaped heredoc marker: `<<-'HEREDOC'`
           foo \#{:bar}
           HEREDOC
         CRYSTAL
+
+      expect_correction source, <<-'CRYSTAL'
+        <<-'HEREDOC'
+          foo \#{:bar}
+          HEREDOC
+        CRYSTAL
     end
 
     it "fails if a heredoc contains escaped interpolation and escaped escape sequences" do
-      expect_issue subject, <<-'CRYSTAL'
+      source = expect_issue subject, <<-'CRYSTAL'
         <<-HEREDOC
         # ^^^^^^^^ error: Use an escaped heredoc marker: `<<-'HEREDOC'`
           foo \\t \#{:bar}
           HEREDOC
         CRYSTAL
+
+      expect_correction source, <<-'CRYSTAL'
+        <<-'HEREDOC'
+          foo \\t \#{:bar}
+          HEREDOC
+        CRYSTAL
     end
 
     it "passes if a heredoc contains normal and escaped escape sequences" do
@@ -71,12 +83,18 @@ module Ameba::Rule::Style
     end
 
     it "fails if a heredoc contains escaped escape sequences" do
-      expect_issue subject, <<-'CRYSTAL'
+      source = expect_issue subject, <<-'CRYSTAL'
         <<-HEREDOC
         # ^^^^^^^^ error: Use an escaped heredoc marker: `<<-'HEREDOC'`
           \\t \\n
           HEREDOC
         CRYSTAL
+
+      expect_correction source, <<-'CRYSTAL'
+        <<-'HEREDOC'
+          \\t \\n
+          HEREDOC
+        CRYSTAL
     end
 
     it "passes if an escaped heredoc contains interpolation" do
@@ -123,12 +141,18 @@ module Ameba::Rule::Style
     end
 
     it "fails if an escaped heredoc doesn't contain interpolation" do
-      expect_issue subject, <<-CRYSTAL
+      source = expect_issue subject, <<-CRYSTAL
         <<-'HEREDOC'
         # ^^^^^^^^^^ error: Use an unescaped heredoc marker: `<<-HEREDOC`
           foo
           HEREDOC
         CRYSTAL
+
+      expect_correction source, <<-CRYSTAL
+        <<-HEREDOC
+          foo
+          HEREDOC
+        CRYSTAL
     end
   end
 end
diff --git a/src/ameba/rule/style/heredoc_escape.cr b/src/ameba/rule/style/heredoc_escape.cr
index bc332bc78..bcb3705ab 100644
--- a/src/ameba/rule/style/heredoc_escape.cr
+++ b/src/ameba/rule/style/heredoc_escape.cr
@@ -48,21 +48,27 @@ module Ameba::Rule::Style
       return unless code = node_source(node, source.lines)
       return unless code.starts_with?("<<-")
 
-      body = code.lines[1..-2].join('\n')
+      lines = code.lines
+      body = lines[1..-2].join('\n')
 
       if code.starts_with?("<<-'")
         return if has_escape_sequence?(expr.value) || has_escaped_escape_sequence?(body)
 
         marker = code.lchop("<<-'").match!(/^(\w+)/)[1]
         msg = MSG_ESCAPE_NOT_NEEDED % marker
+        corrected_marker = "<<-#{marker}"
       else
         return if !has_escape_sequence?(expr.value) || has_escape_sequence?(body)
 
         marker = code.lchop("<<-").match!(/^(\w+)/)[1]
         msg = MSG_ESCAPE_NEEDED % marker
+        corrected_marker = "<<-'#{marker}'"
       end
 
-      issue_for node, msg
+      issue_for node, msg do |corrector|
+        lines[0] = lines[0].sub(/^<<-'?#{marker}'?/, corrected_marker)
+        corrector.replace(node, lines.join('\n'))
+      end
     end
 
     private def has_escape_sequence?(value : String)