NPM 启动错误 - 文件路径找不到 JSON 包文件

Question

First time poster, thanks in advance for the help!

I'm trying to complete my first project and am running into a few issues. The main one being that when I hit npm start I get hit with this error message -

I've tried hitting npm install before I run it but to no avail. Does anyone have any ideas?!

Thanks!

Answer 1

Without the contents of the package.json I can only guess... As some of the comments have pointed our as well, make sure your node or npm command can navigate to/see your script file

---

Context:

But there are 2 concepts here. node & npm

1. Node is a runtime:

In order to run a node script you'll need the node command (within the context of the project your working on, so make sure your cli is in the root of your project) like this:

node ./folder/to/your-script.js

2. NPM is a package manager.

...and it relies on having a package.json in the same directory as where you're running the npm command for most of it's commands other than init (which creates the package.json file for you)

---

Problem:

The second screenshot is the clue here.

You tried running npm start , where the error message is:

missing script: start

This means that your scripts block does not contain a start property

Thus it seems to me as if you are mixing the 2 concepts.

1. If you wanted to run the script without a package.json you can use the node <filename.js> command
2. If you have dependencies, and want to make your life a little more convenient if you have a lot of other commands and dependencies, you can use the npm run <script> command.

(Side-note: npm start is a special case that seems to be able to run or without the run keyword, which I didn't know as well until I just tested it now :P)

---

Solution:

Therefor to get closer to what your expecting, we can modify the package.json as per below:

You can also create custom aliases for commands within the scripts block (inside the package.json ):

 "scripts": {
   "start": "node ./some-path/to/your-script.js"
   "bar": "npm run foo",
   "foo": "node ./folder/to/your-script.js"
 }

You'll notice, you can reference sibling script aliases in other script commands as well (you can also add non node commands in here, like git , etc..)

Thus with the above in your package.json you'll have access to the following commands when running npm in the same directory as the package.json .

npm start , npm run foo or npm run bar