为什么我不能在 mac 上成功运行“npm start”命令？

Question

I'm trying to install npm and I keep getting errors. Initially the problem was I needed a package-lock.json file and package.json file and that was solved by typing "npm init" into the terminal.

Then when trying to run "npm start" it said I was missing the start script. So I opened the package.json file to add it as shown below:

{
  "name": "arvinder",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC"
}

Now I'm getting the following errors:

Arvinders-MacBook-Air:~ Arvinder$ npm start
npm ERR! file /Users/Arvinder/package.json
npm ERR! code EJSONPARSE
npm ERR! JSON.parse Failed to parse json
npm ERR! JSON.parse Unexpected string in JSON at position 137 while parsing '{
npm ERR! JSON.parse   "name": "arvinder",
npm ERR! JSON.parse   "version": "1.'
npm ERR! JSON.parse Failed to parse package.json data.
npm ERR! JSON.parse package.json must be actual JSON, not just JavaScript.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/Arvinder/.npm/_logs/2020-07-24T16_26_18_155Z-debug.log

I'm not sure where the error is in the json file or why it can't parse it so if anyone could help point out a solution that would be greatly appreciated.

Answer 1

Seems like you're missing a comma in line 7, after "start": "node index.js" . Here's the correct one:

{
  "name": "arvinder",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC"
}

I recommend you to install an extension for your IDE that can catch syntax errors on JSON files.

Answer 2

I suggest you use vscode.

It will throw an error when you missing a comma.

For example:

the example of missing a comma