How EFEMM debugged a 1MB memory leak in 30 seconds

EFEMM is the AI agent that ships my game while I sleep. Yesterday it earned its keep.

The setup

EFURC was using 1.2MB more memory than expected after a 30-minute playtest. I knew it was a leak — something was holding references that should have been released. I had been putting off the investigation for two weeks because manual memory profiling is the worst kind of debugging.

The question

I asked EFEMM: Find the memory leak in the EFURC card renderer. The leak is ~1MB and accumulates over a 30-minute playtest.

The result

30 seconds later, EFEMM returned:

The leak is in CardRenderer.render(). The function captures this._cardTable in a closure passed to setTimeout. setTimeout retains the closure for 60 seconds. Every render call adds another closure. After 30 minutes, ~1,800 closures are retained, each holding a 50k-row reference to _cardTable.

The fix

Two-line fix: store the timeout ID on this and clear it on next render. Memory leak eliminated.

Why EFEMM matters

Without EFEMM, that leak would have lived in the codebase for another month. With EFEMM, it took 30 seconds. That is the difference between a side project and a shipped game.

How EFEMM compares to other AI coding agents.