Merge pull request #726 from koic/fix_an_incorrect_autocorrect_for_rails_dot_separated_keys

[Fix #725] Fix an incorrect autocorrect for `Rails/DotSeparatedKeys`

Author: koic

changelog/fix_an_incorrect_autocorrect_for_rails_dot_separated_keys.md

@@ -0,0 +1 @@
+* [#725](https://github.com/rubocop/rubocop-rails/issues/725): Fix an incorrect autocorrect for `Rails/DotSeparatedKeys` when a key starts with dot. ([@koic][])

lib/rubocop/cop/rails/dot_separated_keys.rb

@@ -53,7 +53,7 @@ def should_convert_scope?(scope_node)
         end
 
         def new_key(key_node, scope_node)
-          "'#{scopes(scope_node).map(&:value).join('.')}.#{key_node.value}'"
+          "'#{scopes(scope_node).map(&:value).join('.')}.#{key_node.value}'".squeeze('.')
         end
 
         def scopes(scope_node)

spec/rubocop/cop/rails/dot_separated_keys_spec.rb

@@ -19,6 +19,8 @@
                     ^^^^^^^^^^^^^^^^^^^ Use the dot-separated keys instead of specifying the `:scope` option.
       I18n.t :key, scope: :one
                    ^^^^^^^^^^^ Use the dot-separated keys instead of specifying the `:scope` option.
+      I18n.t '.key', scope: :one
+                     ^^^^^^^^^^^ Use the dot-separated keys instead of specifying the `:scope` option.
     RUBY
 
     expect_correction(<<~RUBY)
@@ -30,6 +32,7 @@
       I18n.t 'one.two.key'
       I18n.t 'one.two.key'
       I18n.t 'one.key'
+      I18n.t 'one.key'
     RUBY
   end