在 npm 脚本中运行 2 个命令（nodemon && sass --watch）

Question

I have a package.json file looks like this.

"scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node src/app.js",
    "dev": "nodemon src/app.js -e js,hbs ",
    "scss": "sass --watch public/scss:public/css",
    "both": "nodemon src/app.js -e js,hbs && sass --watch public/scss:public/css",
    "both2" : "npm run dev && npm run scss"
  },

I wonder why I cannot run these 2 commands:

"both": "nodemon src/app.js -e js,hbs && sass --watch public/scss:public/css"

by

npm run both

When I try to run it, only the first command is working.

Github repository is below, just in case you need some testing.

https://github.com/tuanphanfi/weather-app-nodejs/

Answer 1

Use a package called concurrently .

npm install concurrently

Then you can make a script called both

"both": "concurrently \"nodemon src/app.js -e js,hbs\" \"sass --watch public/scss:public/css\""

See javascript - How can I run multiple npm scripts in parallel?

Answer 2

On UNIX-like systems you can just use & instead of && to chain your commands. & is used for parallel script execution whereas && causes a sequential execution , meaning the 2nd one starts only when the 1st has finished successfully.

cmd1 &  cmd2 & ...     # parallel 
cmd1 && cmd2 && ...    # sequential 

Whereas on Windows-Systems prepending each of your commands with start and chaining them with && seems to do the trick...

start cmd1 && start cmd2 && start ... 

For cross-platform solutions, see fi either concurrently , like Namko suggests, or npm-run-all . Those solve other problems as well, that might or might not occur when using the above platform-specific solutions (problems like weired/mixed terminal-outputs, multiple terminals/windows, bad control over process/thread-termination etc.)...