From 335ddd90db70458ecda523395dfef0132aa3b46c Mon Sep 17 00:00:00 2001
From: sakuraya <sakuraya@blue-pixel.info>
Date: Wed, 10 Apr 2019 03:25:27 +0900
Subject: [PATCH] [Fix #6914] Fix an error for `Rails/RedundantAllowNil` when
 with interpolations

---
 CHANGELOG.md                                       | 5 +++++
 lib/rubocop/cop/rails/redundant_allow_nil.rb       | 6 +++---
 spec/rubocop/cop/rails/redundant_allow_nil_spec.rb | 8 ++++++++
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5159ed5a16c..552299ee801 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### Bug fixes
+
+* [#6914](https://github.com/rubocop-hq/rubocop/issues/6914): [Fix #6914] Fix an error for `Rails/RedundantAllowNil` when with interpolations. ([@Blue-Pix][])
+
 ### Changes
 
 * [#5977](https://github.com/rubocop-hq/rubocop/issues/5977): Remove Performance cops. ([@koic][])
@@ -3929,3 +3933,4 @@
 [@anuja-joshi]: https://github.com/anuja-joshi
 [@XrXr]: https://github.com/XrXr
 [@thomthom]: https://github.com/thomthom
+[@Blue-Pix]: https://github.com/Blue-Pix
diff --git a/lib/rubocop/cop/rails/redundant_allow_nil.rb b/lib/rubocop/cop/rails/redundant_allow_nil.rb
index be75c159246..2f5934b5649 100644
--- a/lib/rubocop/cop/rails/redundant_allow_nil.rb
+++ b/lib/rubocop/cop/rails/redundant_allow_nil.rb
@@ -79,10 +79,10 @@ def find_allow_nil_and_allow_blank(node)
           node.each_descendant do |descendant|
             next unless descendant.pair_type?
 
-            key = descendant.children.first.value
+            key = descendant.children.first.source
 
-            allow_nil = descendant if key == :allow_nil
-            allow_blank = descendant if key == :allow_blank
+            allow_nil = descendant if key == 'allow_nil'
+            allow_blank = descendant if key == 'allow_blank'
 
             break if allow_nil && allow_blank
           end
diff --git a/spec/rubocop/cop/rails/redundant_allow_nil_spec.rb b/spec/rubocop/cop/rails/redundant_allow_nil_spec.rb
index 0ce9ffd5a9e..760661d4a0b 100644
--- a/spec/rubocop/cop/rails/redundant_allow_nil_spec.rb
+++ b/spec/rubocop/cop/rails/redundant_allow_nil_spec.rb
@@ -73,4 +73,12 @@
       RUBY
     end
   end
+
+  context 'when using string interpolation' do
+    it 'registers no offense' do
+      expect_no_offenses(<<-'RUBY'.strip_indent)
+        validates :details, "path_to_dynamic_validation/#{with_interpolation}": true
+      RUBY
+    end
+  end
 end