add Previewnet codeword for address generation (#703)

Author: nvdtf

address.go

@@ -108,6 +108,8 @@ func chainCustomizer(chain ChainID) uint64 {
 		return 0
 	case Testnet:
 		return invalidCodeTestNetwork
+	case Previewnet:
+		return invalidCodePreviewNetwork
 	case Emulator, Localnet, Benchnet, BftTestnet:
 		return invalidCodeTransientNetwork
 	default:
@@ -271,6 +273,9 @@ const (
 
 	// invalidCodeTransientNetwork  is the invalid codeword used for transient test networks.
 	invalidCodeTransientNetwork = uint64(0x1cb159857af02018)
+
+	// invalidCodePreviewNetwork is the invalid codeword used for Preview networks.
+	invalidCodePreviewNetwork = uint64(0x5211829E88528817)
 )
 
 // Rows of the generator matrix G of the [64,45]-code used for Flow addresses.

address_test.go

@@ -95,6 +95,7 @@ func TestAddressConstants(t *testing.T) {
 		Mainnet,
 		Testnet,
 		Emulator,
+		Previewnet,
 	}
 
 	for _, net := range networks {
@@ -135,6 +136,7 @@ func TestAddressGeneration(t *testing.T) {
 		Mainnet,
 		Testnet,
 		Emulator,
+		Previewnet,
 	}
 
 	for _, net := range networks {