npm-packages

• Name packages as single words ("smartart"), joined words ("saveform") or hyphenated ("bootstrap-llm-provider")
• The main file name is package-name.js
• Use ESM ("type": "module")
• Use JavaScript, not TypeScript
• Encourage type definitions

package.json

Include these keys:

• name: package-name
• version: semver
• description: 1-line (how it helps developers)
• homepage: typically "https://github.com/sanand0/repo#readme"
• repository: typically { type: "git", url: "https://github.com/sanand0/repo.git" }
• license: "MIT"
• author: typically "Anand S root.node@gmail.com"
• type: "module"
• prettier: { printWidth: 120 }
• files: [ "LICENSE", "README".md, "dist/" ]
• browser: "dist/package-name.min.js" if meant for browsers
• exports: "dist/package-name.min.js" or { ".": { "default": "./dist/package-name.min.js", "types": "./package-name.d.ts" } }
• bin: only for CLI apps
• scripts: typically includes:

  {
    "build": "npx -y esbuild package-name.js --bundle --format esm --minify --outfile=dist/package-name.min.js",
    "lint:oxlint": "npx -y oxlint@1 --fix",
    "lint:js-md": "npx -y prettier@3.5 --print-width 120 --write '**/*.js' '!**/*.min.js' '!dist/**' '**/*.md'",
    "lint:html": "npx -y js-beautify@1 '**/*.html' --type html --replace --indent-size 2 --max-preserve-newlines 1 --end-with-newline",
    "lint": "npm run lint:oxlint && npm run lint:js-md && npm run lint:html",
    "test": "npx -y vitest@3 run --globals",
    "prepublishOnly": "npm run lint && npm run build && npm test"
    // docs, watch, pretest, ...
  }
  

• dependencies: only if required
• devDependencies: only if required. Prefer npx -y in scripts over devDependencies. Used mainly if tests/utilities need packages, e.g. jsdom, playwright, sharp
• peerDepedencies: only if required. E.g. { "bootstrap": "^5.3.7" }
• keywords: [ ... ]

README.md

Include these H2 headings in order:

• Begin with shields, followed by a 1-line description of the package. Shields include

  [![npm version](https://img.shields.io/npm/v/package-name.svg)](https://www.npmjs.com/package/package-name)
  [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
  [![bundle size](https://img.shields.io/bundlephobia/minzip/package-name)](https://bundlephobia.com/package/package-name)
  

• Installation. Typically:

  Add this to your script:
  
  ```js
  import { something } from "package-name";
  ```
  
  To use via CDN, add this to your HTML file:
  
  ```html
  <script type="importmap">
  {
    "imports": {
      "package-name": "https://cdn.jsdelivr.net/npm/package-name@1"
    }
  }
  </script>
  ```
  
  To use locally, install via `npm`:
  
  ```bash
  npm install package-name
  ```
  
  ... and add this to your HTML file:
  
  ```html
  <script type="importmap">
  {
    "imports": {
      "package-name": ""./node_modules/package-name/dist/package-name.js""
    }
  }
  </script>
  ```
  

• Usage. Provide detailed examples covering all scenarios

  • API. Provide API documentation

• Development. Use this content:

  git clone https://github.com/user/package-name.git
  cd package-name
  
  npm install
  npm run lint && npm run build && npm test
  
  npm publish
  git commit . -m"$COMMIT_MSG"; git tag $VERSION; git push --follow-tags
  

• Release notes. This is a list of [x.y.z](https://npmjs.com/package/package-name/v/x.y.y): dd mmm yyyy: Description of the change

• License. Just mention [MIT](LICENSE)

Follow these conventions:

• Code blocks: add language hints (js, html, bash); keep lines ≤ 120 chars
• Examples: minimal, copy-paste-able; inline comments sparingly
• Links: prefer absolute repo URLs for cross-references

Coding style

• Prefer named exports for utilities; default export for the primary function; avoid classes unless needed
• Use JSDoc for params/returns and typedefs; ship .d.ts for public APIs where feasible

Testing style

• Prefer Vitest with jsdom for browser libraries
• Playwright can be used for end-to-end and screenshot tests
• File naming: *.test.js (or *.spec.ts for Playwright suites)
• Style: BDD (describe/it), deterministic tests, small fixtures; mock network when applicable

.gitignore

node_modules/
dist/