Danger JS - File Size Check

fileSize.danger.ts

/**
 * This script serves as a mechanism to ensure that no files exceeding a size of 50MB are committed to the repository.
 * It checks the size of each file that has been modified or created in the current git commit, and alerts the developer if any oversized files are found.
 * 
 * Requirement:
 * 1. **File Size Check**: Before committing files, it's crucial to ensure that file sizes are within reasonable limits to prevent bloating the repository.
 * 
 * Note:
 * - This script can be executed either locally or as part of a CI/CD pipeline.
 * - When executed locally, it can be run with the `danger local` option or integrated with git hooks using tools such as Husky to perform checks when a developer executes a git commit.
 * - When integrated into a CI/CD pipeline, it utilizes the `danger` library to report oversized files and fail the pipeline if necessary.
 */

import { fail, danger } from 'danger';
import fs from 'fs';

// Get the list of modified and created files from the git diff

const modifiedFiles = danger.git.modified_files || [];
const createdFiles = danger.git.created_files || [];
const allFiles = [...modifiedFiles, ...createdFiles];

const sizeLimit = 50 // In MBs

function generateFailMessage(file: string, fileSizeInMB: number): string {
    return `🚨 ${file} is ${fileSizeInMB.toFixed(2)} MB and exceeds 50MB limit. Please reduce file size. 🚨`;
}

function checkForFileSize(file: string) {
    if (fs.existsSync(file)) {
        // Get file stats to retrieve its size
        const stats = fs.statSync(file);
        const fileSizeInBytes = stats.size;
        const fileSizeInMB = fileSizeInBytes / (1024 * 1024);  // Convert size to Megabytes (MB)

        if (fileSizeInMB > 50) {
            const failMessage = generateFailMessage(file, fileSizeInMB);
            fail(failMessage);
            process.exit(1);
        }
    }
}

// Iterate through all the files and check their sizes
allFiles.forEach(file => {
    checkForFileSize(file);
});