fix(dev): drain connections before force-closing the dev server

Author: danielroe

packages/nuxt-cli/src/dev/listen.ts

@@ -69,6 +69,9 @@ const ANY_HOSTS = new Set(['', '0.0.0.0', '::'])
 constLOOPBACK_HOSTS=newSet(['localhost','127.0.0.1','::1'])
 constDEFAULT_PORTS={http: 80,https: 443}asconst
 
+/** How long in-flight requests have to finish before their sockets are killed. */
+constCONNECTION_DRAIN_TIMEOUT_MS=1000
+
 /**
  * Render a URL for display: the port is omitted when it is the protocol
  * default, and percent-encoding is decoded so a non-ASCII `baseURL` is
@@ -270,8 +273,23 @@ export async function listen(handler: RequestListener, options: ListenOptions =
 close: async()=>{
 awaittunnel?.close()
 returnnewPromise<void>((resolve,reject)=>{
-server.close(error=>(error ? reject(error) : resolve()))
-server.closeAllConnections?.()
+letforceClose: NodeJS.Timeout|undefined
+server.close((error)=>{
+if(forceClose){
+clearTimeout(forceClose)
+}
+if(error){
+reject(error)
+}
+else{
+resolve()
+}
+})
+// Sockets waiting on keep-alive are closed at once, so shutdown is only
+// delayed while a request is actually being served.
+server.closeIdleConnections?.()
+forceClose=setTimeout(()=>server.closeAllConnections?.(),CONNECTION_DRAIN_TIMEOUT_MS)
+forceClose.unref()
 })
 },
 }

packages/nuxt-cli/test/unit/listen.spec.ts

@@ -202,6 +202,35 @@ describe('listen', () => {
 })
 })
 
+describe('listener.close',()=>{
+it('should let an in-flight request finish',async()=>{
+letrespond: (()=>void)|undefined
+constlistener=awaitlisten((_req,res)=>{
+respond=()=>res.end('done')
+},{port: 0,hostname: '127.0.0.1',showURL: false})
+
+constresponse=fetch(listener.url)
+awaitvi.waitFor(()=>expect(respond).toBeDefined())
+
+constclosed=listener.close()
+respond!()
+
+awaitexpect((awaitresponse).text()).resolves.toBe('done')
+awaitclosed
+})
+
+it('should not wait for idle keep-alive connections',async()=>{
+constlistener=awaitlisten((_req,res)=>res.end('ok'),{port: 0,hostname: '127.0.0.1',showURL: false})
+
+awaitfetch(listener.url).then(response=>response.text())
+
+conststart=Date.now()
+awaitlistener.close()
+
+expect(Date.now()-start).toBeLessThan(500)
+})
+})
+
 describe('copyURL',()=>{
 afterEach(()=>{
 restoreEnvironment()