@milencode/bundlewatch-parsers

Parse existing bundle analyzer outputs instead of re-analyzing files.

Why?

Existing tools like webpack-bundle-analyzer and rollup-plugin-visualizer already do excellent analysis and visualization. Instead of duplicating that work, BundleWatch parses their output and adds:

• ✅ Time-series tracking (git-based storage)
• ✅ Build comparisons
• ✅ Trend analysis
• ✅ CI/CD integration
• ✅ Alerting

Result: 10-100x faster than re-analyzing files!

Supported Formats

Webpack Stats

import { parseWebpackStats } from '@milencode/bundlewatch-parsers';
import stats from './stats.json';

const metrics = parseWebpackStats(stats, {
  branch: 'main',
  commit: 'abc123',
  estimateCompression: true, // Estimate gzip/brotli sizes
});

// metrics is now in BuildMetrics format
// Ready for comparison, storage, etc.

Coming Soon

• parseRollupVisualizer() - Parse rollup-plugin-visualizer output
• parseViteManifest() - Parse Vite's .vite/manifest.json
• parseNextjsStats() - Parse Next.js build output

Usage with Webpack

// webpack.config.js
const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');

module.exports = {
  plugins: [
    new BundleAnalyzerPlugin({
      analyzerMode: 'json',      // Generate stats.json
      generateStatsFile: true,
      statsFilename: 'stats.json',
    }),
  ],
};

Then in your CI/post-build:

import { parseWebpackStats } from '@milencode/bundlewatch-parsers';
import { GitStorage } from '@milencode/bundlewatch-core';
import fs from 'fs';

// Read their stats
const stats = JSON.parse(fs.readFileSync('dist/stats.json', 'utf-8'));

// Parse to our format (< 1ms)
const metrics = parseWebpackStats(stats);

// Add our layer (time-series tracking)
const storage = new GitStorage();
await storage.save(metrics);

// Compare against baseline
const baseline = await storage.load('main');
const comparison = compare(metrics, baseline);

console.log(comparison); // See what changed!

Performance

Before (re-analyzing files):

• Read all files from disk: ~500ms
• Compress with gzip: ~800ms
• Compress with brotli: ~600ms
• Total: ~2 seconds

After (parsing stats):

• Parse JSON: <1ms
• Total: <1ms ⚡

~2000x faster!

API

parseWebpackStats(stats, options)

Converts webpack stats.json to BuildMetrics format.

Parameters:

• stats - Webpack stats object (from stats.json)
• options (optional):
  • branch - Git branch name
  • commit - Git commit hash
  • estimateCompression - Estimate gzip/brotli sizes (default: true)

Returns: BuildMetrics object

License

MIT