Cyber Typing is a typing-speed test that is part of the pablobanker.dev ecosystem — it reuses the portfolio's design tokens (the same dark background, cyan accent and Geist typography). Across three screens (home, test, results) it measures net and gross WPM, accuracy and consistency, tracks your progress and levels you up as you go. The core principle is that no business logic lives inside Svelte components. A pure, framework-agnostic TypingEngine class takes keystrokes and exposes immutable snapshots; metrics, level progression and the WPM rank are pure modules; and a services layer orchestrates everything without touching the UI. Progression is infinite: each level scales word count, word length, capital letters, punctuation and numbers, and you only advance by hitting the 90% accuracy goal. The rank is derived from the average net WPM of the 10 most recent tests. There is no backend: history, preferences and the current level live in LocalStorage under versioned keys, and every record is re-validated on load with hand-written type guards. Input capture is accent- and IME-safe (dead keys and composition events are handled explicitly), paste is blocked so metrics can't be gamed, and the whole thing is covered by Vitest unit tests plus a Playwright end-to-end flow running against the production build.
No business logic inside Svelte components: a pure TypingEngine class holds the test state and exposes immutable snapshots, pure modules compute metrics, progression and rank, and a services layer orchestrates results, stats and persistence — components only render.
Dead keys (ABNT2) and IME composition fire events in different orders across browsers, which can lose or double-count accented characters.
Input is read from a transparent overlaid input's buffer: during a composition the buffer is not cleared and the commit happens on compositionend, with NFC normalization and code-point iteration.
Typing logic tangled into components is hard to test and easy to break.
The engine is a pure class that knows nothing about Svelte: it takes press/space/backspace, holds internal state and exposes an immutable snapshot the UI mirrors — so the core runs and is tested entirely in Node.
All history lives in LocalStorage, where data can be stale, malformed or from an older version of the app.
Versioned keys plus hand-written type guards that re-validate every record on load: invalid entries are dropped individually, old results are back-filled instead of discarded, and history is capped at the 100 most recent.
