add hw2

node_modules/pino/lib/worker-pipeline.js

@@ -0,0 +1,38 @@
+'use strict'
+
+const EE = require('events')
+const loadTransportStreamBuilder = require('./transport-stream')
+const { pipeline, PassThrough } = require('stream')
+
+// This file is not checked by the code coverage tool,
+// as it is not reliable.
+
+/* istanbul ignore file */
+
+module.exports = async function ({ targets }) {
+  const streams = await Promise.all(targets.map(async (t) => {
+    const fn = await loadTransportStreamBuilder(t.target)
+    const stream = await fn(t.options)
+    return stream
+  }))
+  const ee = new EE()
+
+  const stream = new PassThrough({
+    autoDestroy: true,
+    destroy (_, cb) {
+      ee.on('error', cb)
+      ee.on('closed', cb)
+    }
+  })
+
+  pipeline(stream, ...streams, function (err) {
+    if (err && err.code !== 'ERR_STREAM_PREMATURE_CLOSE') {
+      ee.emit('error', err)
+      return
+    }
+
+    ee.emit('closed')
+  })
+
+  return stream
+}