test: upgrade to rack 3.x and add workaround to rack 3.1.x

related: pact-foundation/pact-mock_service#152

Gemfile

@@ -26,4 +26,5 @@ group :test do
   gem 'faraday', '~>2.0'
   gem 'faraday-retry', '~>2.0'
   gem 'rackup', '~> 2.1'
+  gem 'rack', '>= 3.0', '< 4.0'
 end

spec/lib/rack/webrick.rb

@@ -0,0 +1,12 @@
+module Rack
+    module Handler
+        begin
+          require 'rack/handler/webrick'
+          WEBrick = Class.new(Rack::Handler::WEBrick)
+        rescue LoadError
+          require 'rackup/handler/webrick'
+          WEBrick = Class.new(Rackup::Handler::WEBrick)
+        end
+    end
+  end
+

spec/support/ssl_server.rb

@@ -32,11 +32,20 @@ def webrick_opts port
   require "webrick"
   require "webrick/https"
   require "rack"
-  require "rackup/handler/webrick"
+  begin
+    # For rack <= 3.0.x
+    require 'rack/handler/webrick'
+    opts = webrick_opts(4444)
+    Rack::Handler::WEBrick.run(app, **opts) do |server|
+      @server = server
+    end
+  rescue LoadError
+    # For rack >= 3.1.x
+    require 'rackup/handler/webrick'
+    opts = webrick_opts(4444)
 
-  opts = webrick_opts(4444)
-
-  Rack::Handler::WEBrick.run(app, **opts) do |server|
-    @server = server
+    Rackup::Handler::WEBrick.run(app, **opts) do |server|
+      @server = server
+    end
   end
 end