From b7a2f1d259a363bb3a7d89b6f99303edd41ac0dc Mon Sep 17 00:00:00 2001
From: Daniel Vandersluis <daniel.vandersluis@gmail.com>
Date: Wed, 29 Sep 2021 09:56:06 -0400
Subject: [PATCH] [Fix #10140] Fix false positive for `Layout/DotPosition` when
 a heredoc receives a method on the same line as the start sigil in `trailing`
 style.

---
 .../fix_fix_false_positive_for_layoutdotposition.md    |  1 +
 lib/rubocop/cop/layout/dot_position.rb                 | 10 +++++++---
 spec/rubocop/cop/layout/dot_position_spec.rb           | 10 ++++++++++
 3 files changed, 18 insertions(+), 3 deletions(-)
 create mode 100644 changelog/fix_fix_false_positive_for_layoutdotposition.md

diff --git a/changelog/fix_fix_false_positive_for_layoutdotposition.md b/changelog/fix_fix_false_positive_for_layoutdotposition.md
new file mode 100644
index 00000000000..7e3d11356b8
--- /dev/null
+++ b/changelog/fix_fix_false_positive_for_layoutdotposition.md
@@ -0,0 +1 @@
+* [#10140](https://github.com/rubocop/rubocop/issues/10140): Fix false positive for `Layout/DotPosition` when a heredoc receives a method on the same line as the start sigil in `trailing` style. ([@dvandersluis][])
diff --git a/lib/rubocop/cop/layout/dot_position.rb b/lib/rubocop/cop/layout/dot_position.rb
index 27857e27119..b4e2554607e 100644
--- a/lib/rubocop/cop/layout/dot_position.rb
+++ b/lib/rubocop/cop/layout/dot_position.rb
@@ -68,14 +68,18 @@ def message(dot)
         end
 
         def proper_dot_position?(node)
-          receiver_line = receiver_end_line(node.receiver)
           selector_line = selector_range(node).line
 
-          # receiver and selector are on the same line
-          return true if selector_line == receiver_line
+          # If the receiver is a HEREDOC and the selector is on the same line
+          # then there is nothing to do
+          return true if heredoc?(node.receiver) && node.receiver.loc.first_line == selector_line
 
+          receiver_line = receiver_end_line(node.receiver)
           dot_line = node.loc.dot.line
 
+          # receiver and selector are on the same line
+          return true if selector_line == receiver_line
+
           # don't register an offense if there is a line comment between the
           # dot and the selector otherwise, we might break the code while
           # "correcting" it (even if there is just an extra blank line, treat
diff --git a/spec/rubocop/cop/layout/dot_position_spec.rb b/spec/rubocop/cop/layout/dot_position_spec.rb
index e25974411dc..c13a188e35f 100644
--- a/spec/rubocop/cop/layout/dot_position_spec.rb
+++ b/spec/rubocop/cop/layout/dot_position_spec.rb
@@ -465,5 +465,15 @@
         RUBY
       end
     end
+
+    context 'when there is a heredoc with a following method' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          <<~HEREDOC.squish
+            something
+          HEREDOC
+        RUBY
+      end
+    end
   end
 end