Function TestWantConn_RaceConditionNilContext

internal/pool/want_conn_test.go:457–505

TestWantConn_RaceConditionNilContext tests the race condition where getCtxForDial can return nil after the context is cancelled. This test verifies that the fix in newConn handles nil context gracefully.

(t *testing.T)

// getCtxForDial can return nil after the context is cancelled.
// This test verifies that the fix in newConn handles nil context gracefully.
func TestWantConn_RaceConditionNilContext(t *testing.T) {
	// This test simulates the race condition described in the issue:
	// 1. Main goroutine creates a wantConn with a context
	// 2. Background goroutine starts but hasn't called getCtxForDial yet
	// 3. Main goroutine times out and calls cancel(), setting w.ctx to nil
	// 4. Background goroutine calls getCtxForDial() and gets nil
	// 5. Background goroutine calls newConn(nil, true) which should not panic

	dialCtx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancel()

	w := &wantConn{
		ctx:       dialCtx,
		cancelCtx: cancel,
		result:    make(chan wantConnResult, 1),
	}

	// Simulate the race condition by canceling the context
	// and then trying to get it
	var wg sync.WaitGroup
	wg.Add(1)

	go func() {
		defer wg.Done()
		// Small delay to ensure cancel happens first
		time.Sleep(10 * time.Millisecond)

		// This should return nil after cancel
		ctx := w.getCtxForDial()

		// Verify that we got nil context
		if ctx != nil {
			t.Errorf("Expected nil context after cancel, got %v", ctx)
		}
	}()

	// Cancel the context immediately
	w.cancel()

	wg.Wait()

	// Verify the wantConn state
	if w.isOngoing() {
		t.Error("wantConn should be marked as done after cancel")
	}
	if w.getCtxForDial() != nil {
		t.Error("wantConn.ctx should be nil after cancel")
	}
}

// TestWantConnQueue_dropFrontDone_EmptyQueue tests dropFrontDone on an empty queue.
func TestWantConnQueue_dropFrontDone_EmptyQueue(t *testing.T) {