设置engines似乎没什么用？

> https://docs.npmjs.com/cli/v9/configuring-npm/package-json#engines

You can specify(指定) the version of node that your stuff works on:

```json

{

  "engines": {

    "node": ">=0.10.3 <15"

  }

}

```

And, like with dependencies, if you don't specify(指定) the version (or if you specify(指定) "*" as the version), then any version of node will do.

You can also use the "engines" field to specify(指定) which versions of npm are capable of properly installing your program. For example:

```json

{

  "engines": {

    "npm": "~1.0.20"

  }

}

```

Unless the user has set the [`engine-strict` config](https://docs.npmjs.com/cli/v9/using-npm/config#engine-strict) flag, 

this field is advisory only and will only produce <font color='orange'>warnings</font> when your package is installed as a dependency.

用于指定运行环境，可以不用。