add hw2

node_modules/thread-stream/test/to-file-on-destroy.js

@@ -0,0 +1,23 @@
+'use strict'
+
+const fs = require('fs')
+const { Writable } = require('stream')
+
+function run (opts) {
+  let data = ''
+  return new Writable({
+    autoDestroy: true,
+    write (chunk, enc, cb) {
+      data += chunk.toString()
+      cb()
+    },
+    destroy (err, cb) {
+      // process._rawDebug('destroy called')
+      fs.writeFile(opts.dest, data, function (err2) {
+        cb(err2 || err)
+      })
+    }
+  })
+}
+
+module.exports = run