From 5b1f9f901d1494fda876df9345ce11fb9ebe0d46 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A1n=20Mugnolo?= <adrian@mugnolo.com>
Date: Sun, 14 Jan 2018 11:57:57 -0300
Subject: [PATCH] Make context safe for interpolation

---
 app/helpers/title/title_helper.rb | 10 +++++++++-
 spec/helpers/title_helper_spec.rb |  9 +++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/app/helpers/title/title_helper.rb b/app/helpers/title/title_helper.rb
index ce1a2ce..acb51e0 100644
--- a/app/helpers/title/title_helper.rb
+++ b/app/helpers/title/title_helper.rb
@@ -15,7 +15,7 @@ def initialize(controller_path, action_name, context)
       def to_s
         I18n.t(
           [:titles, controller_name, action_name].join('.'),
-          context.merge(default: defaults)
+          safe_context.merge(default: defaults)
         )
       end
 
@@ -59,6 +59,14 @@ def adjusted_action_name(action_name)
           action_name
         end
       end
+
+      def reserved_keys
+        I18n::RESERVED_KEYS
+      end
+
+      def safe_context
+        context.except(*reserved_keys)
+      end
     end
   end
 end
diff --git a/spec/helpers/title_helper_spec.rb b/spec/helpers/title_helper_spec.rb
index 82e11cb..05c9993 100644
--- a/spec/helpers/title_helper_spec.rb
+++ b/spec/helpers/title_helper_spec.rb
@@ -51,6 +51,15 @@
     expect(helper.title(greeting: 'Hello')).to eq('Hello Caleb')
   end
 
+  it 'makes context safe to be passed as interpolation options' do
+    stub_rails
+    stub_controller_and_action(:users, :show)
+    load_translations(users: { show: 'User' })
+    allow(helper).to receive_message_chain(:controller, :view_assigns).and_return('scope' => 'Foo')
+
+    expect(helper.title).to eq('User')
+  end
+
   def stub_rails
     allow(helper).to receive(:controller_path).and_return('dashboards')
     allow(helper).to receive(:action_name)