Debug Data Loss

Debug Data Loss

When to Use This Skill

Activate this skill when:

• Tasks are mysteriously disappearing without user deletion
• Data loss is suspected but can't be reproduced
• You need to track what code paths are modifying tasks.value
• Cross-tab sync or undo/​redo is suspected of causing data loss

Task Disappearance Logger

Location: src/​utils/​taskDisappearanceLogger.ts

The logger tracks all modifications to the task array and identifies when tasks disappear without explicit user deletion.

Current Status

The logger is auto-enabled on app startup (added for BUG-020 investigation).

• Auto-enable code: src/​main.ts (lines 74-79)
• Periodic snapshots every 30 seconds when enabled
• Persists logs to localStorage

Browser Console API

// Enable/​Disable monitoring
window.taskLogger.enable()
window.taskLogger.disable()

// Check for disappeared tasks (most important!)
window.taskLogger.getDisappearedTasks()

// Get summary of all logging
window.taskLogger.printSummary()

// Search for a specific task in history
window.taskLogger.findTaskInHistory("task title or id")

// Get all logs
window.taskLogger.getLogs()

// Get all snapshots
window.taskLogger.getSnapshots()

// Export logs for analysis
window.taskLogger.exportLogs()

// Clear all history
window.taskLogger.clearHistory()

What Gets Logged

The logger wraps all tasks.value = assignments in these files:

Log Sources

Each log entry includes a source field identifying where the change occurred:

Analyzing Disappearances

When a task disappears, the logger records:

interface DisappearedTask {
  task: { id, title, status, projectId }
  disappearedAt: number      // Timestamp when it vanished
  lastSeenAt: number         // Timestamp of last snapshot containing it
  lastSeenSource: string     // What operation was happening
  disappearedDuring: string  // What operation caused disappearance
  stackTrace?: string        // JavaScript stack trace
  wasUserDeletion: boolean   // false = suspicious disappearance
}

Debugging Workflow

1. Enable logging (auto-enabled for BUG-020):

   window.taskLogger.enable()
   

2. Use the app normally - reproduce the issue if possible

3. Check for disappeared tasks:

   const disappeared = window.taskLogger.getDisappearedTasks()
   console.log(disappeared)
   

4. Analyze the source:

   • Look at disappearedDuring to see what operation caused it
   • Check stackTrace to see the exact code path
   • Compare lastSeenSource vs disappearedDuring

5. Export for detailed analysis:

   const logs = window.taskLogger.exportLogs()
   // Copy/​paste to a file for analysis
   

Removing Auto-Enable

Once BUG-020 is resolved, remove auto-enable from src/​main.ts:

// DELETE these lines (around lines 74-79):
setTimeout(() => {
  taskDisappearanceLogger.enable()
  console.log('%c[TASK-LOGGER] Auto-enabled for BUG-020 investigation', 'color: #4CAF50; font-weight: bold')
}, 2000)

Related

• BUG-020: Tasks randomly disappearing without user deletion
• TASK-022: Task Disappearance Logger & Investigation
• TASK-024: Review Task Disappearance Logs (scheduled review)
• Skill: dev-fix-task-store - General task store debugging