Fix original url instanceOf url.URL (#4955)

packages/datadog-instrumentations/src/url.js

@@ -59,6 +59,10 @@ addHook({ name: names }, function (url) {
           isURL: true
         })
       }
+
+      static [Symbol.hasInstance] (instance) {
+        return instance instanceof URL
+      }
     }
   })
 

packages/datadog-instrumentations/test/url.spec.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const agent = require('../../dd-trace/test/plugins/agent')
+const { assert } = require('chai')
 const { channel } = require('../src/helpers/instrument')
 const names = ['url', 'node:url']
 
@@ -68,6 +69,13 @@ names.forEach(name => {
           }, sinon.match.any)
         })
 
+        it('instanceof should work also for original instances', () => {
+          const OriginalUrl = Object.getPrototypeOf(url.URL)
+          const originalUrl = new OriginalUrl('https://www.datadoghq.com')
+
+          assert.isTrue(originalUrl instanceof url.URL)
+        })
+
         ;['host', 'origin', 'hostname'].forEach(property => {
           it(`should publish on get ${property}`, () => {
             const urlObject = new url.URL('/path', 'https://www.datadoghq.com')