accounts + main: Allow new accounts with 0 balance

accounts/service_test.go

@@ -571,9 +571,10 @@ func TestAccountService(t *testing.T) {
 			acct := &OffChainBalanceAccount{
 				ID:             testID,
 				Type:           TypeInitialBalance,
-				CurrentBalance: 1234,
+				CurrentBalance: 0,
 				Invoices: AccountInvoices{
-					testHash: {},
+					testHash:  {},
+					testHash2: {},
 				},
 				Payments: make(AccountPayments),
 			}
@@ -589,7 +590,7 @@ func TestAccountService(t *testing.T) {
 				AddIndex:    12,
 				SettleIndex: 12,
 				Hash:        testHash,
-				AmountPaid:  777,
+				AmountPaid:  1000,
 				State:       invpkg.ContractSettled,
 			}
 
@@ -598,7 +599,25 @@ func TestAccountService(t *testing.T) {
 				acct, err := s.store.Account(testID)
 				require.NoError(t, err)
 
-				return acct.CurrentBalance == (1234 + 777)
+				return acct.CurrentBalance == 1000
+			})
+
+			// Then settle a second invoice.
+			lnd.invoiceChan <- &lndclient.Invoice{
+				AddIndex:    13,
+				SettleIndex: 13,
+				Hash:        testHash2,
+				AmountPaid:  777,
+				State:       invpkg.ContractSettled,
+			}
+
+			// Ensure that the balance now adds up to the sum of
+			// both invoices.
+			assertEventually(t, func() bool {
+				acct, err := s.store.Account(testID)
+				require.NoError(t, err)
+
+				return acct.CurrentBalance == (1000 + 777)
 			})
 		},
 	}, {

accounts/store.go

@@ -107,10 +107,6 @@ func (s *BoltStore) NewAccount(balance lnwire.MilliSatoshi,
 	expirationDate time.Time, label string) (*OffChainBalanceAccount,
 	error) {
 
-	if balance == 0 {
-		return nil, fmt.Errorf("a new account cannot have balance of 0")
-	}
-
 	// If a label is set, it must be unique, as we use it to identify the
 	// account in some of the RPCs. It also can't be mistaken for a hex
 	// encoded account ID to avoid confusion and make it easier for the CLI

accounts/store_test.go

@@ -16,13 +16,8 @@ func TestAccountStore(t *testing.T) {
 	store, err := NewBoltStore(t.TempDir(), DBFilename)
 	require.NoError(t, err)
 
-	// An initial balance of 0 is not allowed, but later we can reach a
-	// zero balance.
-	_, err = store.NewAccount(0, time.Time{}, "")
-	require.ErrorContains(t, err, "cannot have balance of 0")
-
 	// Create an account that does not expire.
-	acct1, err := store.NewAccount(123, time.Time{}, "foo")
+	acct1, err := store.NewAccount(0, time.Time{}, "foo")
 	require.NoError(t, err)
 	require.False(t, acct1.HasExpired())
 

cmd/litcli/accounts.go

@@ -114,10 +114,6 @@ func createAccount(ctx *cli.Context) error {
 		args = args.Tail()
 	}
 
-	if initialBalance <= 0 {
-		return fmt.Errorf("initial balance cannot be smaller than 1")
-	}
-
 	req := &litrpc.CreateAccountRequest{
 		AccountBalance: initialBalance,
 		ExpirationDate: expirationDate,