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@davidfirst davidfirst commented Sep 16, 2025

Summary

This PR implements esbuild-based bundling for the Bit CLI, continuing the work from #7180. The bundled version provides faster startup times and simplified deployment while maintaining full compatibility with Bit's component system.

Key Changes

  • Merged master into bit-bundle branch with careful preservation of bundling-specific modifications
  • Fixed module resolution issues for @teambit packages with problematic exports configuration
  • Added ESM bridge files (esm.mjs) for components using node-babel-mocha environment to support ESM imports in bundled context
  • Preserved bundling optimizations including manifestsMap conversion to function for proper hoisting
  • Maintained compatibility with both bundled and unbundled execution modes

Performance Comparison

Approach Bundle Size Startup Time Status
Unbundled (baseline) N/A 0.57s ✅ Works
Attempt 1: Bundle all (eager) 92MB 2.2s ❌ Too slow
Attempt 2: Externalize 5 big pkgs ~50MB 1.8s ⚠️ Still slower
Attempt 3: Babel lazy loading ~50MB Unknown ❌ Dependency issues
Attempt 5: Bundle @teambit only 11MB Unknown ⚠️ Runtime error

Key Takeaways

  1. Bundle size ≠ startup speed - 46% size reduction only gave 18% speed improvement (Attempt 1 → 2)
  2. Eager loading is the main problem - esbuild loads all modules at startup regardless of bundle size
  3. Lazy loading is crucial - but we couldn't verify its actual impact due to implementation issues

Testing

Bundle builds successfully and runs without errors:

node node_modules/@teambit/bit/dist/bundle/bundle.js

Related Work

Continuation of #7180

This implementation builds upon Gilad's original bundling work, bringing it up to date with current master and resolving compatibility issues that arose from recent ESM adoption across the codebase.

# Conflicts:
#	scopes/harmony/bit/manifests.ts
# Conflicts:
#	scopes/harmony/bit/load-bit.ts
#	scopes/harmony/bit/manifests.ts
# Conflicts:
#	scopes/harmony/bit/manifests.ts
GiladShoham and others added 18 commits December 16, 2024 13:19
# Conflicts:
#	.gitignore
#	package.json
#	scopes/harmony/bit/app.ts
#	scopes/harmony/bit/bootstrap.ts
#	scopes/harmony/bit/load-bit.ts
#	scopes/harmony/cli/cli-parser.ts
#	scopes/harmony/config/config.main.runtime.ts
#	scopes/react/react-native/react-native.main.runtime.ts
#	scopes/react/react/jest/jest.base.config.js
#	scopes/react/react/jest/jest.cjs.config.js
Fix path resolution for @teambit packages that have problematic exports adding .ts extension. Use createRequire from working directory and check for files with common extensions to avoid resolution errors.
- Keep bundling-specific logic in app.ts for bundle functionality
- Update manifests.ts to latest version from master with all new aspects
- Preserve esbuild dependencies and bundle script in package.json
- Use master versions for improved type imports and path resolution
- Maintain bundling output directory in gitignore
- Convert manifestsMap to function for bundling hoisting support
- Use explicit aspect paths (.aspect) for all imports in manifests.ts
- Comment out requireAspects calls (incompatible with bundled environment)
- Comment out yargs import in cli-parser (bundling issue)
- Use regular import for SchemaExtractor (not just type)
- Remove ObjectsAspect (package doesn't exist)
- Fix VueAspect import path to vue.aspect
- Maintain original pattern: const manifestsMap = getManifestsMap() at top
Add esm.mjs files to components that use node-babel-mocha env to support
ESM imports when components are imported in bundled environment.
@davidfirst davidfirst marked this pull request as draft September 16, 2025 15:33
@davidfirst davidfirst changed the title Bit bundle2 feat: implement esbuild bundling for Bit CLI with ESM support Sep 16, 2025
- Add config-store, version-history, ci, and cli-mcp-server aspects to core-aspects-ids.ts
- Update core-aspects-exports.ts with corresponding exports
- Ensures all recent core aspects are included in esbuild bundle generation
- Add esm.mjs files for config-store, ci, and cli-mcp-server aspects
- Enables proper ESM module resolution during bundle generation
- Fixes esbuild errors for missing esm.mjs files
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3 participants