Reuse the exception class name in all places in the wrapper

actionpack/lib/action_dispatch/middleware/exception_wrapper.rb

@@ -45,13 +45,14 @@ class ExceptionWrapper
     def initialize(backtrace_cleaner, exception)
       @backtrace_cleaner = backtrace_cleaner
       @exception = exception
+      @exception_class_name = @exception.class.name
       @wrapped_causes = wrapped_causes_for(exception, backtrace_cleaner)
 
       expand_backtrace if exception.is_a?(SyntaxError) || exception.cause.is_a?(SyntaxError)
     end
 
     def unwrapped_exception
-      if wrapper_exceptions.include?(exception.class.to_s)
+      if wrapper_exceptions.include?(@exception_class_name)
         exception.cause
       else
         exception
@@ -59,7 +60,7 @@ def unwrapped_exception
     end
 
     def rescue_template
-      @@rescue_templates[@exception.class.name]
+      @@rescue_templates[@exception_class_name]
     end
 
     def status_code
@@ -68,7 +69,7 @@ def status_code
 
     def exception_trace
       trace = application_trace
-      trace = framework_trace if trace.empty? && !silent_exceptions.include?(@exception.class.name)
+      trace = framework_trace if trace.empty? && !silent_exceptions.include?(@exception_class_name)
       trace
     end