package.json 中的多个命令

Question

This command: "start": "node server/server.js" starts my server, but before running this I also want a command to run automatically: 'webpack' .

I want to build a script that can be run with npm run someCommand - it should first run webpack in the terminal, followed by node server/server.js .

(I know how configure this with gulp, but I don't want to use it)

Answer 1

If I understood you correctly, you want firstly run webpack and after compile run nodejs. Maybe try this:

"start": "webpack && node server/server.js"

Answer 2

The following should work:

"start": "webpack && node server/server.js"

Though, for readability (and especially if you plan on adding additional tasks in the future), you may want to consider creating separate entries for each task and then calling each of those from start . Something like:

{
    "init-assets": "webpack",
    "init-server": "node server/server.js",
    "start": "npm run init-assets && npm run init-server"
}

Answer 3

You can also chain commands like this:

"scripts": {
    "clean": "npm cache clean --force",
    "clean:complete": "npm run clean && npm uninstall -g @angular/cli && rmdir /Q /S node_modules",
    "clean:complete:install": "npm run clean:complete && npm i -g @angular/cli && npm i && npm install --save-dev @angular/cli@latest"
}

Answer 4

Better understand the && operator

In my case the && didn't worked well because one of my commands exited with 1 (error) or 0 (success) depending on the situation AND the && chaining operator works only if the previous command succeeds .

So, to add to other answers here are the options you get to separate commands:

• && run second command only if first succeeds
• || run second command only if first fails

So if you want the second command to run whatever the first has outputted the best way is to do something like (command1 && command2) || command 2 (command1 && command2) || command 2

OS specific chaining operators

Other options are different in unix (linux, macos) and windows environnement

• ; UNIX run the second command whatever the first has outputted
• ; WIN separate command arguments
• & UNIX run first command in the background parallel to the second one
• & WIN run the second command whatever the first has outputted

All chaining operators for windows here and for unix here

Answer 5

Also, along with the accepted answer and @pdoherty926's answer, in case you want to have run two command prompts, you can add "start" before each command:

{
    "init-assets": "webpack",
    "init-server": "node server/server.js",
    "start": "start npm run init-assets && start npm run init-server"
}

Answer 6

You can use a tool like script-launcher to extend the features of you package.json file.

With script-launcher you can use arrays as scripts and reference another script with different arguments, and many more.

Example using script arrays

{
  "scripts": {
    "init": [
      "webpack",
      "node server/server.js"
    ]
  }
}

Use the examples from the Table of Contents on how to implement this.