fix: flaky test TestController_watchAccountChanges by making sure

to check the database transfer after removal event is processed.

services/wallet/transfer/controller.go

@@ -150,8 +150,8 @@ func (c *Controller) startAccountWatcher(chainIDs []uint64) {
 		c.accWatcher = accountsevent.NewWatcher(c.accountsDB, c.accountFeed, func(changedAddresses []common.Address, eventType accountsevent.EventType, currentAddresses []common.Address) {
 			c.onAccountsChanged(changedAddresses, eventType, currentAddresses, chainIDs)
 		})
-		c.accWatcher.Start()
 	}
+	c.accWatcher.Start()
 }
 
 func (c *Controller) onAccountsChanged(changedAddresses []common.Address, eventType accountsevent.EventType, currentAddresses []common.Address, chainIDs []uint64) {

services/wallet/transfer/controller_test.go

@@ -80,26 +80,12 @@ func TestController_watchAccountsChanges(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, ranges)
 
-	ch := make(chan accountsevent.Event)
+	c.accWatcher = accountsevent.NewWatcher(c.accountsDB, c.accountFeed, func(changedAddresses []common.Address, eventType accountsevent.EventType, currentAddresses []common.Address) {
-	// Subscribe for account changes
+		c.onAccountsChanged(changedAddresses, eventType, currentAddresses, []uint64{chainID})
-	accountFeed.Subscribe(ch)
 
-	// Watching accounts must start before sending event.
+		// Quit channel event handler before  destroying the channel
-	// To avoid running goroutine immediately, use any delay.
 		go func() {
 			time.Sleep(1 * time.Millisecond)
-
-		accountFeed.Send(accountsevent.Event{
-			Type:     accountsevent.EventTypeRemoved,
-			Accounts: []common.Address{address},
-		})
-	}()
-
-	c.startAccountWatcher([]uint64{chainID})
-
-	// Wait for event
-	<-ch
-
 			// Wait for DB to be cleaned up
 			c.accWatcher.Stop()
 
@@ -121,6 +107,21 @@ func TestController_watchAccountsChanges(t *testing.T) {
 			require.Nil(t, ranges.tokens.FirstKnown)
 			require.Nil(t, ranges.tokens.LastKnown)
 			require.Nil(t, ranges.tokens.Start)
+		}()
+	})
+	c.startAccountWatcher([]uint64{chainID})
+
+	// Watching accounts must start before sending event.
+	// To avoid running goroutine immediately and let the controller subscribe first,
+	// use any delay.
+	go func() {
+		time.Sleep(1 * time.Millisecond)
+
+		accountFeed.Send(accountsevent.Event{
+			Type:     accountsevent.EventTypeRemoved,
+			Accounts: []common.Address{address},
+		})
+	}()
 }
 
 func TestController_cleanupAccountLeftovers(t *testing.T) {