npm 开始不拾取更新的 package.json

Question

I am writing a node app from scratch, with the following package.json , which is pretty boiler-plate.

{
    "name": "myfirstnodeproject",
    "version": "1.0.1",
    "description": "Learning node",
    "main": "index.js",
    "start": "node server.js",
    "scripts": {
        "test": "echo \"Error: no test specified\" && exit 1"
    },
    "license": "ISC",
    "dependencies": {
        "request": "^2.88.2"
    }
}

I created server.js to look like this:

var http = require("http");

http.createServer((inRequest, inResponse) => {
    inResponse.end("Your IP Address is " + inRequest.connection.remoteAddress);
}).listen(9000);

When I started the app using npm start , it worked fine.

Then, I created a new file called server_time.js :

require("http").createServer((inRequest, inResponse) => {
    const requestModule = require("request");
    requestModule(
        "http://worldtimeapi.org/api/timezone/America/New_York",
        function (inErr, inResp, inBody) {
            inResponse.end(
               `Hello from my first Node Web server: ${inBody}`
            );
        }
    );
}).listen(9000);

I changed the following line in my package.json :

"start": "node server_time.js",

However, Node still seems to pick up server.js instead. I tried npm cache verify , npm cache clear --force , rm -rf node_modules , rm package-lock.json , and npm install again, but the problem didn't seem to go away. I even removed package.json and redefined it, but the value of start when I call npm start is still stale.

Here's an output from my shell:

GsMacbookPro:MyFirstNodeProject g$ cat package.json
{
  "name": "myfirstnodeproject",
  "version": "1.0.1",
  "description": "Learning node",
  "main": "index.js",
  "start": "node server_time.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "G",
  "license": "ISC",
  "dependencies": {
    "request": "^2.88.2"
  }
}
GsMacbookPro:MyFirstNodeProject g$ ls
node_modules        package-lock.json   package.json        server.js       server_time.js
GsMacbookPro:MyFirstNodeProject g$ npm start

> myfirstnodeproject@1.0.1 start /Users/g/Repos/MyFirstNodeProject
> node server.js

Before someone asks, node version is v10.16.3 , and npm version is 6.9.0 .

Answer 1

The reason why npm start currently works for you is because npm will default some script values based on package contents.

If there is a server.js file in the root of your package, then npm will default the start command to node server.js .

See here:

• npm.js - default values

So your start field inside package.json wasn't actually doing anything because it was not under scripts , which is where it should belong.

The correct approach is to update your package.json so that it looks like the following:

{
  "name": "myfirstnodeproject",
  "version": "1.0.1",
  "description": "Learning node",
  "main": "index.js",
  "scripts": {
    "start": "node server_time.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "G",
  "license": "ISC",
  "dependencies": {
    "request": "^2.88.2"
  }
}

Answer 2

Try:

{
    "name": "myfirstnodeproject",
    "version": "1.0.1",
    "description": "Learning node",
    "main": "server_time.js",
    "scripts": {
        "test": "echo \"Error: no test specified\" && exit 1",
        "start": "node server_time.js"
    },
    "license": "ISC",
    "dependencies": {
        "request": "^2.88.2"
    }
}

and then npm run start .