Principle:Mlc ai Web llm Package Build Pipeline

Knowledge Sources	npm package.json Rollup Documentation Mlc_ai_Web_llm
Domains	Build_System, Package_Management
Last Updated	2026-02-14 22:30 GMT

Overview

Technique for defining the build, test, and distribution pipeline of a TypeScript npm package through declarative configuration in package.json.

Description

A package build pipeline orchestrates the transformation of TypeScript source code into a distributable npm package. For web-llm, this involves:

• Bundling -- Rollup compiles and bundles TypeScript source files from src/ into ES module output in lib/
• Type generation -- TypeScript compiler emits .d.ts declaration files alongside the JavaScript output
• Artifact cleanup -- A post-build script removes unnecessary build artifacts
• Quality gates -- ESLint enforces code style rules, Prettier enforces formatting, and Husky runs checks on git commit via hooks
• Testing -- Jest runs unit and integration tests with coverage reporting
• Distribution -- The files field restricts the published package to only the lib/ directory

The pipeline defines the complete lifecycle from source code to published package.

Usage

Use this principle when understanding how web-llm is built, tested, and published. The build pipeline is the entry point for:

• Setting up a local development environment
• Contributing code changes (lint, test, format must pass)
• Building the library for local consumption
• Understanding what artifacts are published to npm

Theoretical Basis

ES Module Package Design

The package is configured as "type": "module", meaning all .js files are treated as ES modules. The entry points are:

• main: "lib/index.js" -- The primary JavaScript entry point
• types: "lib/index.d.ts" -- TypeScript type declarations

Build Stages

Pseudo-code logic:

# Abstract build pipeline description
1. rollup -c              # Bundle src/ → lib/ using rollup.config.js
2. cleanup-index-js.sh    # Remove duplicate/unnecessary index files
3. eslint + prettier      # Verify code quality (lint stage)
4. jest --coverage        # Run tests (test stage)
5. npm publish            # Publish lib/ to npm registry (release stage)

Dependency Categories

• Runtime dependencies -- Shipped with the package; kept minimal (only loglevel)
• Dev dependencies -- Used only during development and build; not included in published package
• Peer dependencies -- None; the MLC AI runtime packages are dev dependencies bundled into the output

Related Pages

• Implementation:Mlc_ai_Web_llm_Package_Configuration