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go.channel_never_closed

Stability Medium

Detects channels that are created but never closed, causing goroutines waiting on them to leak.

Why It Matters

Unclosed channels cause:

Goroutine leaks — Receivers block forever waiting
Memory leaks — Blocked goroutines hold references
Deadlocks — Range loops never terminate
Resource exhaustion — Slow accumulation of leaked goroutines

Example

// ❌ Before (channel never closed)
func producer(ch chan int) {
    for i := 0; i < 10; i++ {
        ch <- i
    }
    // Channel never closed - consumers block forever!
}

func consumer(ch chan int) {
    for v := range ch { // Blocks forever after producer done
        process(v)
    }
}

// ✅ After (channel closed)
func producer(ch chan int) {
    defer close(ch)
    for i := 0; i < 10; i++ {
        ch <- i
    }
}

func consumer(ch chan int) {
    for v := range ch { // Terminates when channel closed
        process(v)
    }
}

What Unfault Detects

make(chan T) without corresponding close()
Channels passed to functions without closing
Range loops over channels that are never closed

Auto-Fix

Unfault adds defer close(ch):

func produce(ch chan<- int) {
    defer close(ch)
    // ... produce values
}