dsh-pwa-plugin

DSH PWA Plugin

PWA plugin for DeepSeek Harness that adds offline support and install-as-app capability.

Features

• Service Worker with smart caching strategy
• PWA Manifest with proper maskable icons
• Automatic updates — new versions activate silently and reload the page exactly once (a first-ever visit never reloads)
• Versioned caches — cache names carry the package version, so upgrading the plugin purges stale caches automatically
• Offline-first for static assets
• Official DSH whale icon — derived from the upstream SVG favicon

Installation

1. Add as a dependency

From npm (once published):

npm install dsh-pwa-plugin

Or, for a local checkout, in your DSH web profile's package.json:

{
  "dependencies": {
    "dsh-pwa-plugin": "file:~/workspace/dsh-pwa-plugin"
  }
}

2. Register the plugin

In your profile's cordis.patch.yml:

- insert:
    - id: dsh-pwa
      name: 'dsh-pwa-plugin'

3. Restart DSH

dsh web

Generate PNG Icons

The plugin ships pre-built PNG icons. To regenerate (requires sharp):

cd dsh-pwa-plugin
node scripts/generate-icons.js

This reads the official public/favicon.svg and produces:

File	Size	Purpose
icon-192.png	192×192	Regular (any)
icon-192-maskable.png	192×192	Maskable (20% safe zone)
icon-512.png	512×512	Regular (any)
icon-512-maskable.png	512×512	Maskable (20% safe zone)

How It Works

1. The host plugin serves /sw.js (stamped with the package version), /manifest.webmanifest, and icon files
2. It injects a service worker registration script into the HTML
3. The service worker pre-caches static assets (one failing URL never aborts the install) and caches them for offline use
4. The manifest enables installing the app as a PWA
5. Updates are detected automatically and silently activated; the page reloads once per update
6. DSH's built-in /favicon.svg is used as-is (not overridden)

Caching Strategy

Resource Type	Strategy	Description
HTML	Network-first	Always fetches the latest version; only storable 200 responses become the offline fallback
JS/CSS/Fonts/Images	Cache-first	Kept in a cache named after the package version, so an upgrade invalidates it without a manual version bump
Dynamic DSH routes	Not intercepted	/api, /auth-api, /oauth, /open-in-app, /plugins, /ws, /hooks and /dsh-pwa always reach the network
Cache-Control: no-store	Never cached	The server's directive wins over the service worker
API/WebSocket	Not cached	Always goes to the network

Limitations

• Requires HTTPS to work (except localhost)
• Service worker cannot cache API calls
• Updates require a page reload (automatic after detection)

Project Structure

dsh-pwa-plugin/
├── src/
│   ├── host/
│   │   └── index.js          # Host plugin (Node.js)
│   └── sw.js                 # Service Worker
├── public/
│   ├── manifest.webmanifest  # PWA Manifest
│   ├── favicon.svg           # DSH whale icon (same as upstream)
│   └── icons/                # PWA icons (maskable + regular)
├── scripts/
│   ├── generate-icons.js     # Icon generator (sharp)
│   ├── install.js            # Verification script
│   └── verify.js             # Verification
├── cordis.patch.yml          # Plugin registration
├── LICENSE
└── package.json

Testing

npm test

Zero-dependency suite on Node's built-in runner (node --test):

• test/manifest.test.mjs — manifest required fields, icon densities (regular + maskable at 192/512) and that every icon file exists on disk.
• test/sw.test.mjs — the service worker evaluated against a fake self: install/activate cache lifecycle (per-URL resilient pre-cache, versioned cache names, orphan cleanup), the bypass rules (non-GET, non-HTTP schemes, /api, /auth-api, /oauth, /open-in-app, /plugins, /ws, /hooks, /dsh-pwa, websocket upgrades), network-first HTML with its offline fallbacks, cache-first statics with the store guard (200/basic/ no-store), and the GET_VERSION / SKIP_WAITING messages.
• test/host.test.mjs — route registration (sw, manifest, 4 icons, version), response headers, the package-version stamping of /sw.js, the index-HTML script injection, the registration script's reload guard (executed in a sandboxed VM), and the effect cleanup used on HMR unmounts.

License

MIT