mtg-online-drafter/docs/development/devlog/2024-12-18-191500_fix_strict_action_payload.md

2024-12-18 - Fix Strict Action Payload Construction

Problem

The user reported a server crash/error: Rule Violation [UNKNOWN]: Cannot read properties of undefined (reading 'type'). This occurred when resolving lands or casting spells. The error log "UNKNOWN" indicated the server received a null/undefined action object within the game_strict_action event payload. The server expects socket.emit('game_strict_action', { action: { type: '...' } }). The client was emitting socket.emit('game_strict_action', { type: '...' }) (missing the action wrapper).

Root Cause

When refactoring for the Strict Actions, the frontend calls for handleZoneDrop (Battlefield), handleCardDrop, and handlePlayerDrop were updated to emit the new event name game_strict_action, but the payload structure was not updated to wrap the data in an { action: ... } object as expected by server/index.ts.

Solution

Updated GameView.tsx in three locations (handleZoneDrop, handleCardDrop, handlePlayerDrop) to correctly wrap the payload:

socketService.socket.emit('game_strict_action', {
  action: {
    type: '...',
    ...
  }
});

Outcome

Client strict actions now match the server's expected payload structure. Actions like playing lands or casting spells should now execute defined logic instead of crashing or being treated as unknown.