Ignore leading slashes in string literal arguments for `Rails.root.jo…

…in` and multiple slashes in string literal arguments for `Rails.root.join` and `File.join`

lib/rubocop/cop/rails/file_path.rb

@@ -6,6 +6,9 @@ module Rails
       # Identifies usages of file path joining process to use `Rails.root.join` clause.
       # It is used to add uniformity when joining paths.
       #
+      # NOTE: This cop ignores leading slashes in string literal arguments for `Rails.root.join`
+      #       and multiple slashes in string literal arguments for `Rails.root.join` and `File.join`.
+      #
       # @example EnforcedStyle: slashes (default)
       #   # bad
       #   Rails.root.join('app', 'models', 'goober')
@@ -99,6 +102,7 @@ def check_for_file_join_with_rails_root(node)
           return unless file_join_nodes?(node)
           return unless node.arguments.any? { |e| rails_root_nodes?(e) }
           return if node.arguments.any?(&:variable?)
+          return if node.arguments.any? { |arg| string_contains_multiple_slashes?(arg) }
 
           register_offense(node, require_to_s: true) do |corrector|
             autocorrect_file_join(corrector, node) unless node.first_argument.array_type?
@@ -111,6 +115,8 @@ def check_for_rails_root_join_with_string_arguments(node)
           return unless rails_root_join_nodes?(node)
           return unless node.arguments.size > 1
           return unless node.arguments.all?(&:str_type?)
+          return if node.arguments.any? { |arg| string_with_leading_slash?(arg) }
+          return if node.arguments.any? { |arg| string_contains_multiple_slashes?(arg) }
 
           register_offense(node, require_to_s: false) do |corrector|
             autocorrect_rails_root_join_with_string_arguments(corrector, node)
@@ -121,15 +127,25 @@ def check_for_rails_root_join_with_slash_separated_path(node)
           return unless style == :arguments
           return unless rails_root_nodes?(node)
           return unless rails_root_join_nodes?(node)
-          return unless node.arguments.any? { |arg| string_with_slash?(arg) }
+          return unless node.arguments.any? { |arg| string_contains_slash?(arg) }
+          return if node.arguments.any? { |arg| string_with_leading_slash?(arg) }
+          return if node.arguments.any? { |arg| string_contains_multiple_slashes?(arg) }
 
           register_offense(node, require_to_s: false) do |corrector|
             autocorrect_rails_root_join_with_slash_separated_path(corrector, node)
           end
         end
 
-        def string_with_slash?(node)
-          node.str_type? && node.source.include?(File::SEPARATOR)
+        def string_contains_slash?(node)
+          node.str_type? && node.value.include?(File::SEPARATOR)
+        end
+
+        def string_contains_multiple_slashes?(node)
+          node.str_type? && node.value.include?('//')
+        end
+
+        def string_with_leading_slash?(node)
+          node.str_type? && node.value.start_with?("/")
         end
 
         def register_offense(node, require_to_s:, &block)
@@ -227,7 +243,7 @@ def autocorrect_rails_root_join_with_string_arguments(corrector, node)
 
         def autocorrect_rails_root_join_with_slash_separated_path(corrector, node)
           node.arguments.each do |argument|
-            next unless string_with_slash?(argument)
+            next unless string_contains_slash?(argument)
 
             index = argument.source.index(File::SEPARATOR)
             rest = inner_range_of(argument).adjust(begin_pos: index - 1)

spec/rubocop/cop/rails/file_path_spec.rb

@@ -388,6 +388,46 @@
         RUBY
       end
     end
+
+    context 'when using Rails.root.join with a leading slash' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          Rails.root.join('/app/models')
+        RUBY
+      end
+    end
+
+    context 'when using Rails.root.join with mixed leading and normal path strings' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          Rails.root.join('/app', 'models')
+        RUBY
+      end
+    end
+
+    context 'when using Rails.root.join with mixed normal and leading path strings' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          Rails.root.join('app', '/models')
+        RUBY
+      end
+    end
+
+    context 'when using Rails.root.join with multiple slashes in a path' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          Rails.root.join('public//', 'assets')
+        RUBY
+      end
+    end
+
+    context 'when using File.join with multiple slashes in a path' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          File.join(Rails.root, 'public//', 'assets')
+        RUBY
+      end
+    end
   end
 
   context 'when EnforcedStyle is `arguments`' do
@@ -658,5 +698,45 @@
         RUBY
       end
     end
+
+    context 'when using Rails.root.join with a leading slash' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          Rails.root.join('/app/models')
+        RUBY
+      end
+    end
+
+    context 'when using Rails.root.join with mixed leading and normal path strings' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          Rails.root.join('/app', 'models')
+        RUBY
+      end
+    end
+
+    context 'when using Rails.root.join with mixed normal and leading path strings' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          Rails.root.join('app', '/models')
+        RUBY
+      end
+    end
+
+    context 'when using Rails.root.join with multiple slashes in a path' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          Rails.root.join('public//', 'assets')
+        RUBY
+      end
+    end
+
+    context 'when using File.join with multiple slashes in a path' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          File.join(Rails.root, 'public//', 'assets')
+        RUBY
+      end
+    end
   end
 end