DEV: Allow webmock to intercept FinalDestination::HTTP requests (#20575)

lib/final_destination/http.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
-class FinalDestination::HTTP < Net::HTTP
+class FinalDestination
+  module SSRFSafeNetHTTP
     def connect
       original_open_timeout = @open_timeout
       return super if @ipaddr
@@ -10,7 +11,8 @@ class FinalDestination::HTTP < Net::HTTP
       # This iteration through addresses would normally happen in Socket#tcp
       # We do it here because we're tightly controlling addresses rather than
       # handing Socket#tcp a hostname
-    ips = FinalDestination::SSRFDetector.lookup_and_filter_ips(@address, timeout: @connect_timeout)
+      ips =
+        FinalDestination::SSRFDetector.lookup_and_filter_ips(@address, timeout: @connect_timeout)
 
       ips.each_with_index do |ip, index|
         debug "[FinalDestination] Attempting connection to #{ip}..."
@@ -37,4 +39,9 @@ class FinalDestination::HTTP < Net::HTTP
     def current_time
       Process.clock_gettime(Process::CLOCK_MONOTONIC)
     end
+  end
+
+  class HTTP < ::Net::HTTP
+    include SSRFSafeNetHTTP
+  end
 end

spec/support/final_destination_helper.rb

@@ -7,7 +7,15 @@ WebMock::HttpLibAdapterRegistry.instance.register(
 
     def self.enable!
       FinalDestination.send(:remove_const, :HTTP)
-      FinalDestination.send(:const_set, :HTTP, Net::HTTP)
+
+      # At this point, `Net::HTTP` has already been patched by WebMock so we need to re-declare `FinalDestination::HTTP`
+      # but inherit from the patched `Net::HTTP` class. This is to allow requests made using `FinalDestination::HTTP` to be
+      # intercepted by WebMock.
+      FinalDestination.send(
+        :const_set,
+        :HTTP,
+        Class.new(Net::HTTP) { include FinalDestination::SSRFSafeNetHTTP },
+      )
     end
 
     def self.disable!