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go.uncancelled_context

Stability Medium

Detects context.WithCancel() and context.WithTimeout() without calling the cancel function, leaking resources.

Why It Matters

Uncancelled contexts cause:

Memory leaks — Context goroutines never terminate
Resource exhaustion — Over time, leaks accumulate
Timer leaks — WithTimeout/WithDeadline leak timers
Goroutine leaks — Background goroutines never stop

Example

// ❌ Before (cancel never called)
func process() {
    ctx, _ := context.WithTimeout(context.Background(), time.Second)
    doWork(ctx)
    // Timer goroutine leaked!
}

// ✅ After (cancel called)
func process() {
    ctx, cancel := context.WithTimeout(context.Background(), time.Second)
    defer cancel() // Always call cancel!
    doWork(ctx)
}

What Unfault Detects

context.WithCancel() with unused cancel func
context.WithTimeout() without defer cancel
context.WithDeadline() without cleanup
Ignored cancel functions (_)

Auto-Fix

Unfault adds defer cancel():

ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()