test: Switch from leaked-handles to wtfnode (#2604)

See my comments at
https://github.com/cdr/code-server/pull/2563#issuecomment-763394741

test/socket.test.ts

@@ -1,14 +1,16 @@
 import { field, logger } from "@coder/logger"
 import * as fs from "fs-extra"
-import "leaked-handles"
 import * as net from "net"
 import * as path from "path"
 import * as tls from "tls"
 import { Emitter } from "../src/common/emitter"
 import { SocketProxyProvider } from "../src/node/socket"
 import { generateCertificate, tmpdir } from "../src/node/util"
+import * as wtfnode from "./wtfnode"
 
 describe("SocketProxyProvider", () => {
+  wtfnode.setup()
+
   const provider = new SocketProxyProvider()
 
   const onServerError = new Emitter<{ event: string; error: Error }>()

test/wtfnode.ts

@@ -0,0 +1,19 @@
+import * as wtfnode from "wtfnode"
+
+let active = false
+
+export function setup(): void {
+  if (active) {
+    return
+  }
+  active = true
+
+  const interval = 5000
+  const wtfnodeDump = () => {
+    wtfnode.dump()
+    const t = setTimeout(wtfnodeDump, interval)
+    t.unref()
+  }
+  const t = setTimeout(wtfnodeDump, interval)
+  t.unref()
+}