Updated the files.

my-app/node_modules/karma/lib/utils/net-utils.js

@@ -0,0 +1,27 @@
+'use strict'
+
+const net = require('net')
+
+const NetUtils = {
+  bindAvailablePort (port, listenAddress) {
+    return new Promise((resolve, reject) => {
+      const server = net.createServer()
+
+      server
+        .on('error', (err) => {
+          server.close()
+          if (err.code === 'EADDRINUSE' || err.code === 'EACCES') {
+            server.listen(++port, listenAddress)
+          } else {
+            reject(new Error(`Failed to bind ${port}: ` + (err.stack || err)))
+          }
+        })
+        .on('listening', () => {
+          resolve(server)
+        })
+        .listen(port, listenAddress)
+    })
+  }
+}
+
+module.exports = NetUtils