FIX: `assets:precompile:js_processor` task issue (#23219)

* Fix the reference
* Use mutex in non-prod only (…and don't try to build the processor in runtime in prod)

lib/discourse_js_processor.rb

@@ -110,9 +110,6 @@ class DiscourseJsProcessor
     end
 
     def self.generate_js_processor
-      @processor_mutex.synchronize do
-        if Rails.env.development? || Rails.env.test? ||
-             !File.exist?("#{Rails.root}/#{JS_PROCESSOR_PATH}")
       Discourse::Utils.execute_command(
         "yarn",
         "--silent",
@@ -125,8 +122,6 @@ class DiscourseJsProcessor
         "--outfile=#{JS_PROCESSOR_PATH}",
       )
     end
-      end
-    end
 
     def self.create_new_context
       # timeout any eval that takes longer than 15 seconds
@@ -138,7 +133,10 @@ class DiscourseJsProcessor
       ctx.attach("rails.logger.error", proc { |err| Rails.logger.error(err.to_s) })
 
       # Theme template AST transformation plugins
-      generate_js_processor
+      if Rails.env.development? || Rails.env.test?
+        @processor_mutex.synchronize { generate_js_processor }
+      end
+
       ctx.eval(File.read(JS_PROCESSOR_PATH), filename: "js-processor.js")
 
       ctx

lib/tasks/assets.rake

@@ -301,7 +301,7 @@ task "assets:precompile:compress_js" do
 end
 
 task "assets:precompile:js_processor": "environment" do
-  DiscourseJsProcessor.generate_js_processor
+  DiscourseJsProcessor::Transpiler.generate_js_processor
 end
 
 task "assets:precompile": %w[