Cloud Functions模拟器要求安装模块“ firebase-admin”

Question

当我做firebase serve时，我会得到

✔  functions: Using node@6 from host.
✔  functions: Emulator started at http://localhost:5001
i  functions: Watching "/Users/peter/dev/myapp/functions" for Cloud Functions...
i  hosting: Serving hosting files from: public
✔  hosting: Local server: http://localhost:5000
⚠  The Cloud Functions emulator requires the module "firebase-admin" to be installed. This package is in your package.json, but it's not available. You probably need to run "npm install" in your functions directory.
i  functions: Your functions could not be parsed due to an issue with your node_modules (see above)`

my package.json is

`{
  "name": "functions",
  "description": "Cloud Functions for Firebase",
  "scripts": {
    "lint": "eslint .",
    "serve": "firebase serve --only functions",
    "shell": "firebase functions:shell",
    "start": "npm run shell",
    "deploy": "firebase deploy --only functions",
    "logs": "firebase functions:log"
  },
  "engines": {
    "node": "6"
  },
  "dependencies": {
    "cookie-parser": "~1.4.4",
    "debug": "~2.6.9",
    "ejs": "~2.6.1",
    "express": "~4.16.1",
    "firebase-admin": "^7.3.0",
    "firebase-functions": "^2.3.0",
    "http-errors": "~1.6.3",
    "morgan": "~1.9.1"
  },
  "devDependencies": {
    "eslint": "^5.12.0",
    "eslint-plugin-promise": "^4.0.1",
    "firebase-functions-test": "^0.1.6"
  },
  "private": true
}