ngc-rs

A native Rust replacement for ng build in Angular projects. Drop-in swap, ~10× faster on real-world apps.

Benchmarks

Project	ngc-rs	ng build	Speedup
Production Angular v21 app (~1,200 modules, 14 lazy chunks)	~380 ms	~3,800 ms	~10×

Measured with hyperfine on Apple Silicon, -c production (source maps, minification, tree shaking, content-hashed filenames).

Status: v0.7.18 — parallel build pipeline ngc-rs reads angular.json, compiles templates to Ivy, bundles with code splitting, and emits production-ready output with source maps, minified code, tree-shaken exports, and content-hashed filenames. Every hot stage — project resolution, template compilation, TS transform, npm dependency crawl, Angular linker, tree-shaking, bundling, and minification — runs across rayon worker threads. See the milestones for the roadmap toward a full ng build replacement.

Why is it faster?

The Angular CLI build pipeline runs on Node.js and is largely single-threaded. ngc-rs replaces it with a Rust binary that is multi-threaded end-to-end:

• oxc for native JS/TS parsing, codegen, and minification
• rayon for parallel per-file work at every stage
• petgraph for the file dependency graph
• dashmap for a shared canonicalize() cache across worker threads — collapses duplicate filesystem stat syscalls

Additional wins on the critical path:

• PostCSS/Tailwind subprocess overlaps with bundling rather than running after it — ~200 ms of wallclock absorbed
• Per-chunk bundling, minification, and tree-shake all fan out to worker threads
• npm dependency BFS resolves each frontier level in parallel
• Linker (ɵɵngDeclare* → ɵɵdefine* for partially-compiled npm packages) processes all three of its passes in parallel

Type-checking is delegated to tsc --noEmit as a subprocess — we don't reimplement the TypeScript type system.

Installation

cargo install --git https://github.com/lukekania/ngc-rs

Or build from source:

git clone https://github.com/lukekania/ngc-rs.git
cd ngc-rs
cargo build --release

The binary will be at target/release/ngc-rs.

Usage

ngc-rs info

Resolve the project file graph and print a summary:

ngc-rs info --project tsconfig.json

ngc-rs project info
  Files:          1247
  Entry points:   3
  Edges:          4891
  Unresolved:     12

ngc-rs build

Compile templates, transform TypeScript, and produce browser-ready output:

ngc-rs build --project tsconfig.app.json

When an angular.json is found, ngc-rs reads styles, assets, polyfills, and file replacements from it automatically. Output includes:

• dist/main.{hash}.js — ESM bundle with Ivy-compiled templates (content-hashed in production)
• dist/chunk-*.{hash}.js — lazy-loaded route chunks
• dist/main.{hash}.js.map — source maps (production: external files, development: inline)
• dist/index.html — with injected script/style tags
• dist/styles.css — concatenated global stylesheets
• dist/polyfills.js — polyfill imports
• dist/assets/ — copied static assets
• dist/3rdpartylicenses.txt — third-party license texts

Additional flags:

# Production build (minification, source maps, content hashes, npm bundling)
ngc-rs build --project tsconfig.app.json -c production

# Development build (no optimizations, fast iteration)
ngc-rs build --project tsconfig.app.json

# Machine-readable JSON output
ngc-rs build --project tsconfig.app.json --output-json

Benchmark comparison

Reproduce the headline number against ng build with hyperfine:

cargo build --release

hyperfine --warmup 3 \
  "./target/release/ngc-rs build --project /path/to/tsconfig.app.json --out-dir /tmp/ngc-rs-out -c production" \
  "npx ng build --configuration production"

Run the ng build invocation from inside the Angular project directory, or pass a cwd flag. Both commands include full production optimizations.

Development

# Run tests
cargo test --workspace

# Lint
cargo clippy --workspace --all-targets -- -D warnings

# Format
cargo fmt --all

# All checks (CI runs this)
cargo test --workspace && cargo clippy --workspace --all-targets -- -D warnings && cargo fmt --check

Roadmap

See the GitHub milestones for the full plan:

• v0.1 — Project Resolver ✅
• v0.2 — TS Transform ✅ (strip types with oxc, emit plain JS)
• v0.3 — Bundling ✅ (ESM concatenation with dependency ordering)
• v0.4 — Angular Template Compiler ✅ (Ivy codegen, pest parser)
• v0.5 — Build Output Completeness ✅ (angular.json, index.html, styles, assets, polyfills, fileReplacements)
• v0.6 — Code Splitting & Lazy Routes ✅ (dynamic import detection, chunk graph, multi-file output)
• v0.7 — Source Maps & Optimization ✅ (source maps, minification, content hashing, npm bundling)
• v0.7.x — Angular 21 & Performance ✅ (full-pipeline rayon parallelism, overlapped PostCSS, canonicalize cache — 4.2× → ~10× vs ng build)
• v0.8 — Watch Mode & Dev Server
• v1.0 — Angular CLI Drop-in (swap one line in angular.json). Angular linker for partially-compiled npm packages already landed.

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.

License

MIT