NPM中缺少启动脚本

Question

First, sorry for my bad english. I'm trying to deploy an app to Heroku using the command heroku local web in terminal, but I'm getting ERR! missing script: start ERR! missing script: start , even though I have the script in my json file. And if I try to run npm start in terminal the same error appears. I searched for similar problems in Stack Overflow but I couldn't solve. My .json is:

{
  "name": "server",
  "version": "1.0.0",
  "lockfileVersion": 1,
  "requires": true,
  "dependencies": {
    .
    .
    My dependencies here
    .
    .
  },
  "scripts": {
    "start": "node index.js",
    "test": "echo \"Error: nko test specified\" && exit 1"
  }
}

PS.: When I run npm install in terminal, the json file just erases the script and everything I wrote, for example I added "config" : { "port" : "3000" } , but after running npm install it just disappeared.

Answer 1

I think you confused yarn and npm

If you want to use yarn and if you package.json contain a key like start you can call yarn start

But, if you want to work with npm you need to use npm run start the run it's important because npm can't understand.