CODEWITHSUNDEEP
javascriptnode.jspackage.json
Matt
Matt

Reputation: 649

Wait seconds before running next task on scripts package.jscon

What I want to do is when I run npm run dev to execute those both tasks I need to wait for 5 seconds until next task runs.

Run the npm run server wait for 5 seconds and then npm run client

  "scripts": {
    "start": "node ./bin/www",
    "server": "nodemon start",
    "client": "gulp",
    "dev": "concurrently 'npm run server' 'npm run client'", 
}

Upvotes: 23

Views: 18439

Answers (6)

José Antonio Postigo
José Antonio Postigo

Reputation: 2974

Cross platform solution for your particular problem, without installing any additional lib. Just invoking a JS script that waits certain time to end.

"scripts": {
  "start": "node ./bin/www",
  "server": "nodemon start",
  "client": "gulp",
  "sleep5s": "node -e \"setTimeout(() => process.exit(0), 5000)\"",
  "delayed-client": "npm run sleep5s && npm run client",
  "dev": "concurrently npm:server npm:delayed-client",
}

Upvotes: 10

Aryan Arora
Aryan Arora

Reputation: 86

To add onto Littleboy Harry's answer, sleep 5 only works on Linux. For a cross-platform solution, you can use node -e "setTimeout(()=>{},5000)". So you'd want to make your package.json:

"scripts": {
"start": "node ./bin/www",
"server": "nodemon start",
"client": "gulp",
"dev": "npm run server && node -e \"setTimeout(()=>{}, 5000)\" && npm run client", 
}

A couple of points:

  • I added a backslash before the double quotes as an escape sequence since the command takes the script in double quotes too.
  • You can adjust the timeout according to approximately how long it takes to start the server. Right now, it's set to 5000ms (5 seconds).

Upvotes: 0

A Code Cow
A Code Cow

Reputation: 145

node -e "setTimeout(()=>{},5000)" && npm run client

Upvotes: 3

Joshua Pinter
Joshua Pinter

Reputation: 47471

Use Sleep and Background tasks.

Depending on what these tasks do, you might not need concurrently. You might be able to get away with just using & to run one of them as a background task.

The general pattern is as follows:

( sleep 5 && delayed_command ) & immediate_command

So in your case, it would look something like this:

"dev": "( sleep 5 && npm run client ) & npm run server"

If you don't want the output from one of the commands, you can add > /dev/null 2>&1 after the command, like this: 

"dev": "( sleep 5 && npm run client > /dev/null 2>&1 ) & npm run server"

Upvotes: 9

Avantika Saini
Avantika Saini

Reputation: 792

Adding to @TGrif answer, chain scripts with double ampersand && to execute them sequntially. So to execute sleep command first, put && after it and then write npm run client. So the second command(npm run client) will execute only when the first(sleep) is complete.

Upvotes: 1

TGrif
TGrif

Reputation: 5931

Assuming you're on Linux, you can use sleep command:

"dev": "concurrently 'npm run server' 'sleep 5 && npm run client'"

Upvotes: 23

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