- 1 year ago
Check file exists before launch it in webpack npm scripts
In webpack's npm scripts, you can use the fs
module from Node.js to check if a file exists before launching it. Here's an example of how you can do this:
Install the
fs
module: Ensure that thefs
module is installed in your project. If it's not already installed, you can install it by running the following command in your project's root directory:npm install fs
Update your npm script: In your
package.json
file, update the script you want to modify to include a check for file existence. For example, let's assume you have anstart
script that launches a file namedapp.js
. Modify the script as follows:json"scripts": {
"start": "node checkFile.js && node app.js"
}
Create
checkFile.js
script: Create a new JavaScript file namedcheckFile.js
in your project's root directory. This file will contain the logic to check if the file exists. Here's an example implementation:javascriptconst fs = require('fs');
const fileToCheck = 'app.js'; // Update with your file name
if (fs.existsSync(fileToCheck)) {
process.exit(0); // File exists, exit with code 0 (success)
} else {
console.error(`File ${fileToCheck} does not exist.`);
process.exit(1); // File does not exist, exit with code 1 (failure)
}
Customize
fileToCheck
with the name of the file you want to check for existence.Run the npm script: To execute the modified script, run the following command in your project's root directory:
sqlnpm start
This will trigger the
checkFile.js
script first to check if the file exists, and if it does, it will launchapp.js
.
By adding the checkFile.js
script before launching the desired file, you can ensure that the file exists before executing it within your webpack npm script. If the file does not exist, the script will log an error and exit with a non-zero status code, indicating a failure.
Remember to customize the file name and paths to match your specific project structure.