This PR implements comprehensive package size optimization strategies for kr-corekit, addressing the issue of reducing bundle size while maintaining full functionality.

🔧 Problems Fixed

Missing Utility Exports

The README documentation showed formatUtil and deviceUtil in import examples, but these modules were not exported in package/index.ts, causing import errors:

// This was failing before the fix
import { formatUtil, deviceUtil } from "kr-corekit";

Limited Tree-shaking Support

The package lacked proper configuration for modern bundlers to perform optimal dead code elimination, resulting in larger than necessary bundle sizes for users who only needed specific utilities.

✨ Optimizations Implemented

1. Tree-shaking Ready Configuration

Added "sideEffects": false to package.json, enabling aggressive dead code elimination by modern bundlers:

{
  "sideEffects": false
}

2. Individual Module Exports

Implemented granular export paths for all 10 utility modules, allowing users to import specific modules:

{
  "exports": {
    "./stringUtil": {
      "types": "./dist/types/stringUtil/index.d.ts",
      "require": "./dist/types/stringUtil/index.js",
      "import": "./dist/types/stringUtil/index.js"
    }
  }
}

3. Bundle Analysis Tooling

Added monitoring capabilities with npm run analyze:bundle script that provides:

• File sizes of built bundles
• Gzipped size calculations
• Ongoing size monitoring for regression prevention

4. Enhanced Documentation

Updated README with comprehensive tree-shaking usage examples:

// Full import (8.34 kB)
import { stringUtil, numberUtil } from 'kr-corekit';

// Tree-shaken import (only includes used functions)
import { escapeHtml, sum } from 'kr-corekit';

// Module-specific import (maximum optimization)
import { escapeHtml } from 'kr-corekit/stringUtil';
import { sum } from 'kr-corekit/numberUtil';

📊 Bundle Size Impact

• Before: 6.72 kB (2.32 kB gzipped) - missing formatUtil/deviceUtil
• After: 8.34 kB (2.88 kB gzipped) - complete functionality with tree-shaking support
• Tree-shaken: Users only pay for the code they actually use

🧪 Quality Assurance

• ✅ All 140 existing tests continue to pass
• ✅ No security vulnerabilities introduced
• ✅ Backward compatibility maintained
• ✅ TypeScript definitions complete for all export patterns

🎯 Benefits for Users

For Library Users:

• Can now import all documented utilities without errors
• Optimal bundle sizes through selective imports
• Modern bundler compatibility

For Application Developers:

• Smaller production bundles when using specific utilities
• Clear guidance on optimization strategies
• Built-in monitoring tools

Example optimization impact:

// Instead of importing everything (8.34 kB)
import { stringUtil, numberUtil, objectUtil, validationUtil, commonUtil, formatUtil, searchQueryUtil, typeUtil, deviceUtil, cookieUtil } from "kr-corekit";

// Users can now import only what they need
import { escapeHtml, sum, isEmail } from "kr-corekit"; // Much smaller bundle

This implementation follows modern JavaScript packaging best practices while maintaining the library's ease of use and comprehensive functionality.

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.