npm run all Command

The npm run-all is a powerful command used in Node.js projects to execute multiple npm scripts sequentially or in parallel. This approach is especially useful for automating tasks such as linting, testing, building, and deploying the application.

By organizing these tasks into the separate scripts in the package.json file and combining them with the npm run all developers can streamline their workflow and improve productivity.

Prerequisites

• Node.js
• npm

Installation of npm-run-all

To install the npm-run-all package run the following command in the project’s root directory:

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

This will add npm-run-all to the project as a development dependency in which can then be used to the orchestrate multiple npm scripts.

Features of npm-run-all

Some of the key features of the npm-run-all include:

• Run scripts sequentially: Execute tasks one after the other in the defined order.
• Run scripts in parallel: The Execute multiple tasks simultaneously.
• Cross-platform support: Works seamlessly across the different operating systems like Windows, macOS and Linux.
• Task failure detection: Automatically stops the execution of the further tasks if one fails.
• Comprehensive CLI options: Includes options like --parallel, --sequential and --race.

Example: Defining Scripts in package.json

Let's take a simple example where we define multiple npm scripts in package.json file.

{
    "name": "npm-run-all-demo",
    "version": "1.0.0",
    "scripts": {
        "clean": "rm -rf dist/",
        "build": "webpack --config webpack.config.js",
        "test": "jest",
        "lint": "eslint .",
        "start": "node app.js",
        "all": "npm-run-all clean build test lint"
    },
    "devDependencies": {
        "npm-run-all": "^4.1.5",
        "webpack": "^5.0.0",
        "jest": "^26.6.0",
        "eslint": "^7.9.0"
    }
}

Explanation:

• clean: Removes the dist/ directory.
• build: Runs the Webpack build process.
• test: Executes the test cases using the Jest.
• lint: Runs ESLint to the lint the code.
• start: Starts the Node.js application.
• all: Combines all the above tasks using the npm-run-all to execute them sequentially.

Running Scripts Sequentially

To run all the tasks in the order specified in the all script we can run:

npm run all

The tasks will be executed in the following order:

• clean
• build
• test
• lint

Running Scripts in Parallel

If we want to run some tasks in parallel we can use the --parallel flag. For instance, modify the package.json to include the script for the parallel execution:

"scripts": {
    "all:parallel": "npm-run-all --parallel clean build"
}

Now, running:

npm run all:parallel

Output:

npm run all

Running parallel tasks

npm run all:parallel

Example Code: Let's say we have a package.json file with the following scripts defined:

{
    "name": "npm-run-all-example",
    "version": "1.0.0",
    "scripts": {
        "build": "echo 'Building project...'",
        "test": "echo 'Running tests...'",
        "deploy": "echo 'Deploying project...'",
        "all": "npm-run-all build test deploy"
    },
    "devDependencies": {
        "npm-run-all": "^4.1.5"
    }
}

In this example, we have three scripts: build, test and deploy. The all script uses npm-run-all package to the execute all three scripts sequentially.

How to Run the Scripts

Install npm-run-all: First, ensure we have npm-run-all installed in the project. We can do this by the running:

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

Run the all script: After defining the scripts in the package.json we can execute the all script with following command:

npm run all

Output :