fixup! test: use random ports for local verdaccio npm servers

Author: jbedard

tests/legacy-cli/e2e_runner.ts

@@ -9,7 +9,7 @@ import * as path from 'path';
 import { setGlobalVariable } from './e2e/utils/env';
 import { gitClean } from './e2e/utils/git';
 import { createNpmRegistry } from './e2e/utils/registry';
-import { AddressInfo, createServer } from 'net';
+import { AddressInfo, createServer, Server } from 'net';
 
 Error.stackTraceLimit = Infinity;
 
@@ -264,8 +264,11 @@ function printFooter(testName: string, startTime: number) {
 function findFreePort() {
   return new Promise<number>((resolve, reject) => {
     const srv = createServer();
-    srv.once('listening', () => resolve((srv.address() as AddressInfo).port));
-    srv.once('error', reject);
+    srv.once('listening', () => {
+      const port = (srv.address() as AddressInfo).port;
+      srv.close((e) => (e ? reject(e) : resolve(port)));
+    });
+    srv.once('error', (e) => srv.close(() => reject(e)));
     srv.listen();
   });
 }