无法部署云功能

Question

我尝试部署示例函数，但显示错误

该函数的代码如下

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

// Listens for new messages added to /message/:pushId/original and creates an
// uppercase version of the message to /message/:pushId/uppercase
exports.makeUppercase = functions.database.ref('/message/{pushId}/original')
    .onCreate((snapshot, context) => {
      // Grab the current value of what was written to the Realtime Database.
      const original = snapshot.val();
      console.log('Uppercasing', context.params.pushId, original);
      const uppercase = original.toUpperCase();
      // You must return a Promise when performing asynchronous tasks inside a Functions such as
      // writing to the Firebase Realtime Database.
      // Setting an "uppercase" sibling in the Realtime Database returns a Promise.
      return snapshot.ref.parent.child('uppercase').set(uppercase);
    });

我的firebase.json文件

{
  "functions": {
    "predeploy": [
      "npm --prefix \"$RESOURCE_DIR\" run lint"
   ],
    "source": "functions"
  }
}