Minor refactor for previous commit

Add nocov around set_temporary_name, since this cannot be branch
covered on Ruby < 3.3.

Use begin/ensure in spec to ensure that the MyApp constant is
removed even if the spec fails.

Update CHANGELOG.

CHANGELOG

@@ -1,5 +1,7 @@
 = master
 
+* Set temporary name on Ruby 3.3 in middleware plugin for middleware class created (janko) (#344)
+
 * Add break plugin, for using break inside a routing block to return from the block and keep routing (jeremyevans)
 
 = 3.75.0 (2023-12-14)

lib/roda/plugins/middleware.rb

@@ -134,7 +134,9 @@ class Forwarder
         # and store +app+ as the next middleware to call.
         def initialize(mid, app, *args, &block)
           @mid = Class.new(mid)
+          # :nocov:
           @mid.set_temporary_name("#{mid.name}(middleware)") if mid.name && RUBY_VERSION >= "3.3"
+          # :nocov:
           if @mid.opts[:middleware_next_if_not_found]
             @mid.plugin(:not_found, &NEXT_PROC)
           end

spec/plugin/middleware_spec.rb

@@ -149,13 +149,16 @@ def call
     end
     body.must_equal 'anonymous'
 
-    Object.const_set(:MyApp, a)
-    app(:bare) do
-      use a
-      route {}
+    begin
+      Object.const_set(:MyApp, a)
+      app(:bare) do
+        use a
+        route {}
+      end
+      body.must_equal 'MyApp(middleware)'
+    ensure
+      Object.send(:remove_const, :MyApp)
     end
-    body.must_equal 'MyApp(middleware)'
-    Object.send(:remove_const, :MyApp)
   end if RUBY_VERSION >= "3.3"
 
   it "should raise error if attempting to use options for Roda application that does not support configurable middleware" do