add hw2

node_modules/thread-stream/test/never-drain.test.js

@@ -0,0 +1,55 @@
+const { test } = require('tap')
+const ThreadStream = require('../index')
+const { join } = require('path')
+
+function retryUntilTimeout (fn, timeout) {
+  const start = Date.now()
+  return new Promise((resolve, reject) => {
+    async function run () {
+      if (fn()) {
+        resolve()
+        return
+      }
+
+      if (Date.now() - start >= timeout) {
+        reject(new Error('timeout'))
+        return
+      }
+      setTimeout(run, 10)
+    }
+
+    run()
+  })
+}
+
+test('emit warning when the worker gracefully exit without the stream ended', async function (t) {
+  const expectedWarning = 'ThreadStream: process exited before destination stream was drained. this may indicate that the destination stream try to write to a another missing stream'
+  const stream = new ThreadStream({
+    filename: join(__dirname, 'to-next.js')
+  })
+  stream.unref()
+
+  let streamWarning
+  function saveWarning (e) {
+    if (e.message === expectedWarning) {
+      streamWarning = e
+    }
+  }
+  process.on('warning', saveWarning)
+
+  const data = 'hello'.repeat(10)
+  for (let i = 0; i < 1000; i++) {
+    if (streamWarning?.message === expectedWarning) {
+      break
+    }
+    stream.write(data)
+    await new Promise((resolve) => {
+      setTimeout(resolve, 1)
+    })
+  }
+
+  process.off('warning', saveWarning)
+  t.equal(streamWarning?.message, expectedWarning)
+
+  await retryUntilTimeout(() => stream.worker.exited === true, 3000)
+})