refactor: use WaitGroup.Go to simplify code

cmd/chain-receipts/main.go

@@ -154,9 +154,7 @@ func listener(provider *ethrpc.Provider, monitorOptions ethmonitor.Options, rece
 	)
 
 	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
+	wg.Go(func() {
 		for {
 			select {
 			case receipt := <-sub.TransactionReceipt():
@@ -187,7 +185,7 @@ func listener(provider *ethrpc.Provider, monitorOptions ethmonitor.Options, rece
 				return
 			}
 		}
-	}()
+	})
 
 	wg.Wait()
 

cmd/chain-watch/main.go

@@ -178,9 +178,7 @@ func chainWatch(provider *ethrpc.Provider, monitorOptions ethmonitor.Options) (*
 	count := 0
 
 	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
+	wg.Go(func() {
 		for {
 			select {
 			case blocks := <-sub.Blocks():
@@ -210,7 +208,7 @@ func chainWatch(provider *ethrpc.Provider, monitorOptions ethmonitor.Options) (*
 				return
 			}
 		}
-	}()
+	})
 
 	// TODO: we can implement a program, chain-watch-test
 	// which will assert ethmonitor behaviour

ethreceipts/ethreceipts.go

@@ -358,9 +358,7 @@ func (l *ReceiptsListener) FetchTransactionReceiptWithFilter(ctx context.Context
 	// TODO/NOTE: perhaps in an extended node failure. could there be a scenario
 	// where filterer.Exhausted is never hit? and this subscription never unsubscribes..?
 	// don't think so, but we can double check.
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
+	wg.Go(func() {
 		defer sub.Unsubscribe()
 		defer close(mined)
 		defer close(finalized)
@@ -433,7 +431,7 @@ func (l *ReceiptsListener) FetchTransactionReceiptWithFilter(ctx context.Context
 				}
 			}
 		}
-	}()
+	})
 
 	// Wait for the first mined receipt or an exit signal
 	select {

ethreceipts/ethreceipts_test.go

@@ -742,15 +742,13 @@ func TestFiltersAddDeadlock(t *testing.T) {
 
 	// Now try to access the subscriber's filters from another goroutine
 	// This should deadlock if AddFilter is stuck holding the lock
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
+	wg.Go(func() {
 		time.Sleep(100 * time.Millisecond)
 
 		// This will try to acquire s.mu.Lock()
 		filters := sub.Filters()
 		t.Logf("Got %d filters", len(filters))
-	}()
+	})
 
 	done := make(chan struct{})
 	go func() {