A Chrome extension for Berrus RPG that tracks idle job timers, item prices, hiscores, and session statistics.

• Idle Job Timers — Live countdown timers for active jobs with desktop notifications on completion
• Price Tracker — Historical price data with min/max/current and sparkline charts for items seen in shops and the mercadillo
• Hiscore Lookup — Search the Berrus leaderboard by player name and skill category
• Session Stats — Tracks XP gains, items collected, pesetas earned/spent, combat kills/deaths, and jobs completed per session

• TypeScript (strict mode, noUncheckedIndexedAccess)
• Bun (build, test runner, package manager)
• Chrome Extension Manifest V3
• HappyDOM for DOM testing

• Bun v1.3+
• A Chromium-based browser

bun install

bun run build

The extension is output to dist/. Load it in Chrome via chrome://extensions → "Load unpacked" → select the dist/ directory.

bun run build:watch

Rebuilds automatically on file changes in src/.

bun run build -- --prod

Enables minification and strips console.log calls.

src/
├── background/     Service worker — message routing, alarms, notifications, session management
├── content/        Content scripts — DOM extraction (jobs, prices), network interception, session tracking
├── popup/          Extension popup — 4-tab UI (timers, prices, hiscores, session)
├── types/          Shared type definitions (Result, messages, storage schema, domain types)
├── utils/          Shared utilities (storage, alarms, DOM helpers, type guards, logger)
└── test-utils/     Test infrastructure (Chrome API mock, fixture builders)

public/
├── manifest.json   Chrome Extension Manifest V3
└── icons/          Extension icons (16, 48, 128)

scripts/
└── build.ts        Custom Bun-based bundler (4 entry points, static asset copying)

The extension uses Manifest V3 with four entry points:

1. Background service worker (background.js) — Handles all message routing, chrome alarm timers, notifications, session state, and hiscore fetching via a central message handler.
2. Content script (content.js) — Observes the Berrus DOM for jobs, prices, and session events. Sends structured messages to the background worker.
3. Interceptor (interceptor.js) — Runs in the MAIN world at document_start to intercept fetch/XHR responses from the Berrus API before the page processes them.
4. Popup (popup.js) — Read-only UI that queries the background worker for current state and renders four tabs: Timers, Prices, Hiscores, and Session.

Uses a Result<T, E> pattern for all fallible operations. Functions return { ok: true, value } or { ok: false, error } instead of throwing.

Storage, alarms, and notifications use a port pattern — each module defines an interface (e.g. ChromeStoragePort) with a default implementation that wraps the Chrome API, allowing tests to inject in-memory fakes.

bun test

133 tests across 14 files covering:

• Integration tests — Full message → storage → response pipeline, alarm handling, session lifecycle
• Unit tests — Hiscore HTML parsing, notification service, install handler, content script extractors
• Type/utility tests — Result type, type guards, time formatting, DOM builder

Tests use an in-memory Chrome API mock (src/test-utils/chrome-mock.ts) and HappyDOM for DOM operations.

Host permission: https://www.berrus.app/*