Avoid explictly freezing literals strings when possible

Ref: https://github.com/jeremyevans/erubi/pull/33

If the template is compiled with `frozen_string_literals: true`,
then explicitly freezing string is slightly wasteful as it will be
compiled as `opt_str_freeze` instead of a simple `putobject`.

The former has to check wether `String#freeze` was redefined every
time, which while fast is useless extra work.

Gemfile.lock

@@ -53,7 +53,7 @@ PATH
     actionview (7.1.0.alpha)
       activesupport (= 7.1.0.alpha)
       builder (~> 3.1)
-      erubi (~> 1.4)
+      erubi (~> 1.11)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.1, >= 1.2.0)
     activejob (7.1.0.alpha)
@@ -205,7 +205,7 @@ GEM
       http_parser.rb (>= 0.6.0)
     em-socksify (0.3.2)
       eventmachine (>= 1.0.0.beta.4)
-    erubi (1.10.0)
+    erubi (1.11.0)
     et-orbi (1.2.6)
       tzinfo
     event_emitter (0.2.6)

actionview/actionview.gemspec

@@ -36,7 +36,7 @@
   s.add_dependency "activesupport", version
 
   s.add_dependency "builder",       "~> 3.1"
-  s.add_dependency "erubi",         "~> 1.4"
+  s.add_dependency "erubi",         "~> 1.11"
   s.add_dependency "rails-html-sanitizer", "~> 1.1", ">= 1.2.0"
   s.add_dependency "rails-dom-testing", "~> 2.0"
 

actionview/lib/action_view/template/handlers/erb/erubi.rb

@@ -18,6 +18,9 @@ def initialize(input, properties = {})
             properties[:preamble]   ||= ""
             properties[:postamble]  ||= "#{properties[:bufvar]}.to_s"
 
+            # Tell Eruby that whether template will be compiled with `frozen_string_literal: true`
+            properties[:freeze_template_literals] = !Template.frozen_string_literal
+
             properties[:escapefunc] = ""
 
             super
@@ -30,11 +33,11 @@ def add_text(text)
             if text == "\n"
               @newline_pending += 1
             else
-              src << bufvar << ".safe_append='"
-              src << "\n" * @newline_pending if @newline_pending > 0
-              src << text.gsub(/['\\]/, '\\\\\&')
-              src << "'.freeze;"
-
+              with_buffer do
+                src << ".safe_append='"
+                src << "\n" * @newline_pending if @newline_pending > 0
+                src << text.gsub(/['\\]/, '\\\\\&') << @text_end
+              end
               @newline_pending = 0
             end
           end
@@ -44,16 +47,18 @@ def add_text(text)
           def add_expression(indicator, code)
             flush_newline_if_pending(src)
 
-            if (indicator == "==") || @escape
-              src << bufvar << ".safe_expr_append="
-            else
-              src << bufvar << ".append="
-            end
+            with_buffer do
+              if (indicator == "==") || @escape
+                src << ".safe_expr_append="
+              else
+                src << ".append="
+              end
 
-            if BLOCK_EXPR.match?(code)
-              src << " " << code
-            else
-              src << "(" << code << ");"
+              if BLOCK_EXPR.match?(code)
+                src << " " << code
+              else
+                src << "(" << code << ")"
+              end
             end
           end
 
@@ -69,7 +74,7 @@ def add_postamble(_)
 
           def flush_newline_if_pending(src)
             if @newline_pending > 0
-              src << bufvar << ".safe_append='#{"\n" * @newline_pending}'.freeze;"
+              with_buffer { src << ".safe_append='#{"\n" * @newline_pending}" << @text_end }
               @newline_pending = 0
             end
           end