browser-extension-manifest-fields

Parse and resolve browser extension manifest fields to absolute paths.

Parse a manifest.json and resolve file paths for HTML, icons, JSON, scripts, locales, and web accessible resources.

What it does

• HTML, icons, JSON, and scripts declared in the manifest are resolved to absolute file system paths, with public-root inputs normalized (e.g., /something, /public/something, public/something).
• Browser-prefixed manifest keys are honored using the current target browser (e.g., chromium:action for Chrome vs gecko:action for Firefox/Gecko).
• content_scripts entries include both JS and CSS assets when present, preserving ordering.
• web_accessible_resources are passed through as-is for MV3, or strings for MV2.
• Locales under _locales/* are discovered if present.
• In development, manifest data cooperates with the reload pipeline: CSP and permissions are patched, and minimal background entries are ensured so the reloader can be injected.

Usage

import {getManifestFieldsData} from 'browser-extension-manifest-fields'

// Resolve manifest field paths
const fields = getManifestFieldsData({
  manifestPath: '/abs/path/to/manifest.json'
})

Sample output:

{
  "html": {
    "action/index": "/abs/path/to/public/chrome-popup.html",
    "options_ui/page": "/abs/path/to/public/options.html"
  },
  "icons": {
    "16": "/abs/path/to/icons/16.png",
    "48": "/abs/path/to/icons/48.png"
  },
  "json": {
    "declarative_net_request": [
      { "id": "rules", "enabled": true, "path": "/abs/path/to/rules/rules_1.json" }
    ]
  },
  "scripts": {
    "background": {
      "service_worker": "/abs/path/to/src/background.js",
      "type": "module"
    },
    "content_scripts": [
      {
        "matches": ["<all_urls>"],
        "js": ["/abs/path/to/src/content.js"],
        "css": ["/abs/path/to/src/content.css"]
      }
    ]
  },
  "web_accessible_resources": {
    "resources": [
      {
        "resources": ["/abs/path/to/assets/*"],
        "matches": ["<all_urls>"]
      }
    ]
  }
}

API

// manifest-fields
export interface ManifestFields {
  html: Record<string, any>
  icons: Record<string, any>
  json: Record<string, any>
  scripts: Record<string, any>
  web_accessible_resources: Record<string, any>
}

export function getManifestFieldsData(args: {
  manifestPath: string
  browser?: string
}): ManifestFields

License

MIT (c) Cezar Augusto