refactor: rewrite redirect implementation for agent

lib/agent.js

@@ -3,6 +3,7 @@
 const { InvalidArgumentError } = require('./core/errors')
 const { kClients, kRunning, kClose, kDestroy, kDispatch } = require('./core/symbols')
 const DispatcherBase = require('./dispatcher-base')
+const RedirectHandler = require('./handler/RedirectHandler')
 const Pool = require('./pool')
 const Client = require('./client')
 const util = require('./core/util')
@@ -94,6 +95,18 @@ class Agent extends DispatcherBase {
       this[kClients].set(key, dispatcher)
     }
 
+    if (this[kMaxRedirections] > 0) {
+      return dispatcher.dispatch(
+        opts,
+        new RedirectHandler(
+          dispatcher.dispatch.bind(dispatcher),
+          this[kMaxRedirections],
+          opts,
+          handler
+        )
+      )
+    }
+
     return dispatcher.dispatch(opts, handler)
   }