bug: solve history stored in localStorage has no size cap — a speedcuber with thousands of solves will eventually exceed the 5MB localStorage quota, causing a silent QuotaExceededError that wipes the entire session history

[prince-pokharna]

🐛 Problem Statement

CubeIt stores all solve history persistently in the browser's Local Storage:

"All solves and statistics are securely saved in your browser's Local Storage. No database required."

Each solve record likely stores: time, scramble (WCA notation string ~20 chars), timestamp, plus computed Ao5/Ao12 stats. A serious speedcuber might log 10,000+ solves across sessions.

At ~200 bytes per solve × 10,000 solves = ~2 MB. Browsers enforce a 5 MB localStorage quota per origin. When the quota is exceeded, localStorage.setItem() throws a QuotaExceededError (a DOMException). If this exception is not caught, the entire solve attempt is silently lost — no timer result saved, no feedback to the user.

For a speedcuber who just achieved a new personal best, losing that solve to a silent storage error is unacceptable.

💡 Proposed Fix

1. Wrap all localStorage writes in a try/catch with user-facing feedback

// src/utils/storage.js

const MAX_SOLVES = 5000; // configurable cap

export function saveSolve(solve) {
  try {
    const history = loadHistory();

    // Enforce max solve cap — drop oldest entries if needed
    if (history.length >= MAX_SOLVES) {
      history.shift(); // Remove oldest
    }

    history.push(solve);
    localStorage.setItem('cubeit_history', JSON.stringify(history));
  } catch (e) {
    if (e instanceof DOMException && e.name === 'QuotaExceededError') {
      // Notify user — do NOT silently fail
      console.error('[CubeIt] LocalStorage quota exceeded. Pruning oldest 100 solves.');
      pruneOldestSolves(100);
      // Retry once after pruning
      try {
        const pruned = loadHistory();
        pruned.push(solve);
        localStorage.setItem('cubeit_history', JSON.stringify(pruned));
      } catch (retryError) {
        // Storage is critically full — alert user
        alert('⚠️ Storage is full. Please export your history and clear old solves.');
      }
    }
  }
}

function pruneOldestSolves(count) {
  const history = loadHistory();
  history.splice(0, count);
  localStorage.setItem('cubeit_history', JSON.stringify(history));
}

2. Add a storage usage indicator in the Analytics panel

// src/components/Analytics.jsx

function StorageUsageBar() {
  const used = new Blob([localStorage.getItem('cubeit_history') || '']).size;
  const total = 5 * 1024 * 1024; // ~5MB
  const pct = Math.round((used / total) * 100);

  return (
    <div className="storage-indicator">
      <span>Storage: {(used / 1024).toFixed(0)} KB / 5 MB ({pct}%)</span>
      {pct > 80 && (
        <span className="storage-warning">⚠️ Storage nearly full — consider exporting history</span>
      )}
    </div>
  );
}

3. Add a one-click JSON export button

Allow users to export their full history before clearing:

export function exportHistory() {
  const history = loadHistory();
  const blob = new Blob([JSON.stringify(history, null, 2)], { type: 'application/json' });
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = `cubeit_history_${new Date().toISOString().split('T')[0]}.json`;
  a.click();
}

📁 Files to Modify

File	Change
src/utils/storage.js	Add QuotaExceededError handler + auto-pruning
src/components/Analytics.jsx	Add storage usage indicator
src/components/Timer.jsx	Wire export button

Suggested labels: bug, storage, ux

I would like to work on this. Could you please assign it to me?

[prince-pokharna]

Hey @vasanth642 ,
Please assign it to me under GSSoC 2026.
/claim /assign /claim-assignment