Merge pull request #32971 from y-yagi/use_plus_operator_to_unfreeze_string

Enable `Performance/UnfreezeString` cop

11 files changed, 18 insertions, 19 deletions

diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index 885dc0ecba..f07be831d4 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -105,7 +105,7 @@ module ActionDispatch # :nodoc:
 
       def body
         @str_body ||= begin
-          buf = "".dup
+          buf = +""
           each { |chunk| buf << chunk }
           buf
         end
diff --git a/actionpack/lib/action_dispatch/http/url.rb b/actionpack/lib/action_dispatch/http/url.rb
index 35ba44005a..db6d8188d3 100644
--- a/actionpack/lib/action_dispatch/http/url.rb
+++ b/actionpack/lib/action_dispatch/http/url.rb
@@ -157,7 +157,7 @@ module ActionDispatch
           subdomain  = options.fetch :subdomain, true
           domain     = options[:domain]
 
-          host = "".dup
+          host = +""
           if subdomain == true
             return _host if domain.nil?
 
diff --git a/actionpack/lib/action_dispatch/journey/formatter.rb b/actionpack/lib/action_dispatch/journey/formatter.rb
index 0f04839d9b..52396ec901 100644
--- a/actionpack/lib/action_dispatch/journey/formatter.rb
+++ b/actionpack/lib/action_dispatch/journey/formatter.rb
@@ -50,7 +50,7 @@ module ActionDispatch
         unmatched_keys = (missing_keys || []) & constraints.keys
         missing_keys = (missing_keys || []) - unmatched_keys
 
-        message = "No route matches #{Hash[constraints.sort_by { |k, v| k.to_s }].inspect}".dup
+        message = +"No route matches #{Hash[constraints.sort_by { |k, v| k.to_s }].inspect}"
         message << ", missing required keys: #{missing_keys.sort.inspect}" if missing_keys && !missing_keys.empty?
         message << ", possible unmatched constraints: #{unmatched_keys.sort.inspect}" if unmatched_keys && !unmatched_keys.empty?
 
diff --git a/actionpack/lib/action_dispatch/journey/router/utils.rb b/actionpack/lib/action_dispatch/journey/router/utils.rb
index df3f79a407..3bbb187f5c 100644
--- a/actionpack/lib/action_dispatch/journey/router/utils.rb
+++ b/actionpack/lib/action_dispatch/journey/router/utils.rb
@@ -17,11 +17,11 @@ module ActionDispatch
         def self.normalize_path(path)
           path ||= ""
           encoding = path.encoding
-          path = "/#{path}".dup
+          path = +"/#{path}"
           path.squeeze!("/".freeze)
           path.sub!(%r{/+\Z}, "".freeze)
           path.gsub!(/(%[a-f0-9]{2})/) { $1.upcase }
-          path = "/".dup if path == "".freeze
+          path = +"/" if path == "".freeze
           path.force_encoding(encoding)
           path
         end
@@ -32,7 +32,7 @@ module ActionDispatch
           ENCODE   = "%%%02X".freeze
           US_ASCII = Encoding::US_ASCII
           UTF_8    = Encoding::UTF_8
-          EMPTY    = "".dup.force_encoding(US_ASCII).freeze
+          EMPTY    = (+"").force_encoding(US_ASCII).freeze
           DEC2HEX  = (0..255).to_a.map { |i| ENCODE % i }.map { |s| s.force_encoding(US_ASCII) }
 
           ALPHA = "a-zA-Z".freeze
diff --git a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
index 077a83b112..5f5fdbc66a 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
@@ -23,7 +23,7 @@ module ActionDispatch
         if clean_params.empty?
           "None"
         else
-          PP.pp(clean_params, "".dup, 200)
+          PP.pp(clean_params, +"", 200)
         end
       end
 
diff --git a/actionpack/lib/action_dispatch/middleware/debug_locks.rb b/actionpack/lib/action_dispatch/middleware/debug_locks.rb
index 03760438f7..d39377f174 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_locks.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_locks.rb
@@ -63,19 +63,19 @@ module ActionDispatch
 
         str = threads.map do |thread, info|
           if info[:exclusive]
-            lock_state = "Exclusive".dup
+            lock_state = +"Exclusive"
           elsif info[:sharing] > 0
-            lock_state = "Sharing".dup
+            lock_state = +"Sharing"
             lock_state << " x#{info[:sharing]}" if info[:sharing] > 1
           else
-            lock_state = "No lock".dup
+            lock_state = +"No lock"
           end
 
           if info[:waiting]
             lock_state << " (yielded share)"
           end
 
-          msg = "Thread #{info[:index]} [0x#{thread.__id__.to_s(16)} #{thread.status || 'dead'}]  #{lock_state}\n".dup
+          msg = +"Thread #{info[:index]} [0x#{thread.__id__.to_s(16)} #{thread.status || 'dead'}]  #{lock_state}\n"
 
           if info[:sleeper]
             msg << "  Waiting in #{info[:sleeper]}"
diff --git a/actionpack/lib/action_dispatch/middleware/ssl.rb b/actionpack/lib/action_dispatch/middleware/ssl.rb
index 190e54223e..9c9ccfa16f 100644
--- a/actionpack/lib/action_dispatch/middleware/ssl.rb
+++ b/actionpack/lib/action_dispatch/middleware/ssl.rb
@@ -102,7 +102,7 @@ module ActionDispatch
 
       # https://tools.ietf.org/html/rfc6797#section-6.1
       def build_hsts_header(hsts)
-        value = "max-age=#{hsts[:expires].to_i}".dup
+        value = +"max-age=#{hsts[:expires].to_i}"
         value << "; includeSubDomains" if hsts[:subdomains]
         value << "; preload" if hsts[:preload]
         value
@@ -141,7 +141,7 @@ module ActionDispatch
         host = @redirect[:host] || request.host
         port = @redirect[:port] || request.port
 
-        location = "https://#{host}".dup
+        location = +"https://#{host}"
         location << ":#{port}" if port != 80 && port != 443
         location << request.fullpath
         location
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 07e3be4db8..3f7cf0950d 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -308,7 +308,7 @@ module ActionDispatch
           def check_controller_and_action(path_params, controller, action)
             hash = check_part(:controller, controller, path_params, {}) do |part|
               translate_controller(part) {
-                message = "'#{part}' is not a supported controller name. This can lead to potential routing problems.".dup
+                message = +"'#{part}' is not a supported controller name. This can lead to potential routing problems."
                 message << " See https://guides.rubyonrails.org/routing.html#specifying-a-controller-to-use"
 
                 raise ArgumentError, message
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 07d3a41173..acce8a7ef3 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -245,7 +245,7 @@ module ActionDispatch
                   missing_keys << missing_key
                 }
                 constraints = Hash[@route.requirements.merge(params).sort_by { |k, v| k.to_s }]
-                message = "No route matches #{constraints.inspect}".dup
+                message = +"No route matches #{constraints.inspect}"
                 message << ", missing required keys: #{missing_keys.sort.inspect}"
 
                 raise ActionController::UrlGenerationError, message
diff --git a/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb b/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb
index d2685e0452..884fb51d18 100644
--- a/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb
+++ b/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb
@@ -65,7 +65,7 @@ module ActionDispatch
           end
 
           def display_image
-            message = "[Screenshot]: #{image_path}\n".dup
+            message = +"[Screenshot]: #{image_path}\n"
 
             case output_type
             when "artifact"
diff --git a/actionpack/lib/action_dispatch/testing/assertions/response.rb b/actionpack/lib/action_dispatch/testing/assertions/response.rb
index 98b1965d22..8595ea03cf 100644
--- a/actionpack/lib/action_dispatch/testing/assertions/response.rb
+++ b/actionpack/lib/action_dispatch/testing/assertions/response.rb
@@ -79,9 +79,8 @@ module ActionDispatch
         end
 
         def generate_response_message(expected, actual = @response.response_code)
-          "Expected response to be a <#{code_with_name(expected)}>,"\
-          " but was a <#{code_with_name(actual)}>"
-            .dup.concat(location_if_redirected).concat(response_body_if_short)
+          (+"Expected response to be a <#{code_with_name(expected)}>,"\
+          " but was a <#{code_with_name(actual)}>").concat(location_if_redirected).concat(response_body_if_short)
         end
 
         def response_body_if_short