browser-native

Scan your JavaScript project's dependencies and find which ones can be replaced with modern browser/runtime built-in APIs.

Zero dependencies. This tool practices what it preaches.

Install as a Copilot Skill

npx skills add https://github.com/soderlind/browser-native --skill browser-native -g

Once installed, ask Copilot to scan your project:

"Scan my dependencies for browser-native replacements"

Install as a CLI

npm install -g @soderlind/browser-native

Or run directly with npx:

npx @soderlind/browser-native

CLI Usage

# Scan current project
browser-native

# Scan a specific directory
browser-native ../my-app

# Output as Markdown with before/after code examples
browser-native --md

# Save markdown report to file
browser-native --md --out report.md

# Output as JSON (pipe to jq, etc.)
browser-native --json
browser-native --json | jq '.summary'

# Show help
browser-native --help

What it detects

The tool checks your dependencies and devDependencies against a database of 100+ npm packages that have native browser/runtime equivalents:

| Category | Example packages | Native replacement | |---|---|---| | HTTP | axios, node-fetch, request, unfetch | fetch() | | URL / Query | query-string, qs, url-parse, url-search-params-polyfill | URL, URLSearchParams | | Object Utils | lodash.clonedeep, object-assign, object.values, object.hasown | structuredClone(), Object.assign(), Object.values(), Object.hasOwn() | | Array Utils | lodash.flatten, lodash.find, lodash.uniq | .flat(), .find(), [...new Set()] | | UUID | uuid, nanoid, shortid | crypto.randomUUID() | | Date | moment, moment-timezone | Intl.DateTimeFormat | | Promises | bluebird, q, promise-polyfill, promise.allsettled | Promise, Promise.allSettled() | | Strings | left-pad, repeat-string, string.prototype.matchall | .padStart(), .repeat(), .matchAll() | | Type checks | is-number, isarray, is-promise | typeof, Array.isArray() | | Encoding | base-64, js-base64 | btoa(), atob() | | Polyfills | abort-controller, text-encoding, globalthis | Native globals | | Observers | intersection-observer, resize-observer-polyfill | Native APIs | | Crypto | crypto-js (partial) | crypto.subtle | | Streams | web-streams-polyfill | ReadableStream | | FormData | form-data, formdata-polyfill | FormData |

Output formats

Terminal (default)

Colored table with package name, category, replacement API, and confidence level.

Markdown (--md)

Detailed report grouped by category, with:

• Before/after code examples
• Browser support tables (Chrome, Firefox, Safari, Edge, Node.js)
• Confidence indicators and caveats

JSON (--json)

Structured output for piping into other tools:

{
  "summary": {
    "scannedFiles": 1,
    "totalDependencies": 42,
    "replaceableCount": 8,
    "fullReplacements": 5,
    "partialReplacements": 3
  },
  "replaceable": [...]
}

Confidence levels

• Full — drop-in replacement. The native API covers the same functionality.
• Partial — covers most common use cases, but the package may have features the native API doesn't (e.g., qs supports nested objects, URLSearchParams does not).

CI usage

The tool exits with code 1 if replaceable dependencies are found, 0 if none. Use in CI to flag outdated polyfills:

- run: npx @soderlind/browser-native
  continue-on-error: true

Monorepo support

Automatically scans packages/, apps/, libs/, and modules/ subdirectories for additional package.json files.

Requirements

Node.js 18+

Project structure

skills/
  browser-native/
    SKILL.md                        # Copilot skill definition
    scripts/
      cli.js                        # CLI entry point
      scanner.js                    # Package.json scanner
      replacements.js               # Database of 100+ replaceable packages
      formatters/
        table.js                    # ANSI terminal table
        markdown.js                 # Markdown report with code examples
        json.js                     # JSON output
    references/
      replacements-guide.md         # Detailed replacement reference

License

MIT