refactor(BUX-461): small changes after self-review

chainstate/broadcast_client_init.go

@@ -38,8 +38,7 @@ func (c *Client) broadcastClientInit(ctx context.Context) error {
 				Bytes:    int(fee.MiningFee.Bytes),
 			}
 		}
-		lowest := utils.LowestFee(fees, c.options.config.feeUnit)
-		c.options.config.feeUnit = lowest
+		c.options.config.feeUnit = utils.LowestFee(fees, c.options.config.feeUnit)
 	}
 
 	return nil

chainstate/client.go

@@ -100,7 +100,7 @@ func NewClient(ctx context.Context, opts ...ClientOps) (ClientInterface, error)
 	case finalFeeUnit == nil:
 		return nil, errors.New("no fee unit found")
 	case finalFeeUnit.IsZero():
-		return nil, errors.New("fee unit suggests no fees (free)")
+		client.options.logger.Info().Msg("fee unit suggests no fees (free)")
 	default:
 		client.options.logger.Info().Msgf("using fee unit: %s", finalFeeUnit)
 	}

utils/fees_test.go

@@ -57,6 +57,19 @@ func TestIsLowerThan(t *testing.T) {
 		assert.True(t, one.IsLowerThan(&two))
 		assert.False(t, two.IsLowerThan(&one))
 	})
+
+	t.Run("zero as bytes in denominator", func(t *testing.T) {
+		one := FeeUnit{
+			Satoshis: 1,
+			Bytes:    0,
+		}
+		two := FeeUnit{
+			Satoshis: 2,
+			Bytes:    0,
+		}
+		assert.False(t, one.IsLowerThan(&two))
+		assert.False(t, two.IsLowerThan(&one))
+	})
 }
 
 func TestLowestFee(t *testing.T) {