How to Run Multiple Scripts in Parallel with Yarn

In Yarn, running multiple scripts in parallel can be achieved through various methods, with common approaches including the use of concurrently, npm-run-all, or simple shell command combinations.

1. Using concurrently: concurrently is an npm package designed to execute multiple commands simultaneously. First, install this package:

   bash
   npm install concurrently --save-dev

   Then, in the package.json scripts section, define the use of concurrently to run multiple scripts:

   json
   {
     "scripts": {
       "start": "concurrently "npm run script1" "npm run script2""
     }
   }

   Here, script1 and script2 represent the names of the scripts you wish to run in parallel. This command launches both scripts, executing them concurrently.

2. Using npm-run-all: Another tool is npm-run-all, which supports running multiple npm scripts either in parallel or sequentially. First, install this utility:

   bash
   npm install npm-run-all --save-dev

   Use it in package.json to run scripts in parallel:

   json
   {
     "scripts": {
       "start": "npm-run-all --parallel script1 script2"
     }
   }

   Applying the --parallel flag ensures that script1 and script2 execute in parallel.

3. Using Shell Commands: If you prefer not to introduce additional dependencies, shell commands can be used to run scripts in parallel:

   json
   {
     "scripts": {
       "start": "npm run script1 & npm run script2"
     }
   }

   The & symbol enables commands to run concurrently on Unix-like systems. On Windows, the start command achieves the same effect.

All these methods facilitate parallel script execution with Yarn, and the choice depends on project requirements and team preferences.