feat: support custom mnemonics in in-process testing network

testutil/network/network.go

@@ -80,6 +80,7 @@ type Config struct {
 	TimeoutCommit    time.Duration              // the consensus commitment timeout
 	ChainID          string                     // the network chain-id
 	NumValidators    int                        // the total number of validators to create and bond
+	Mnemonics        []string                   // custom user-provided validator mnemonics
 	BondDenom        string                     // the staking bond denomination
 	MinGasPrices     string                     // the minimum gas prices each validator will accept
 	AccountTokens    sdk.Int                    // the amount of unique validator tokens (e.g. 1000node0)
@@ -327,14 +328,25 @@ func New(l Logger, baseDir string, cfg Config) (*Network, error) {
 		if err != nil {
 			return nil, err
 		}
+
 		tmCfg.P2P.ListenAddress = p2pAddr
 		tmCfg.P2P.AddrBookStrict = false
 		tmCfg.P2P.AllowDuplicateIP = true
 
-		nodeID, pubKey, err := genutil.InitializeNodeValidatorFiles(tmCfg)
+		var (
+			nodeID string
+			pubKey cryptotypes.PubKey
+		)
+
+		if i < len(cfg.Mnemonics) && cfg.Mnemonics[i] != "" {
+			nodeID, pubKey, err = genutil.InitializeNodeValidatorFilesFromMnemonic(tmCfg, cfg.Mnemonics[i])
+		} else {
+			nodeID, pubKey, err = genutil.InitializeNodeValidatorFiles(tmCfg)
+		}
 		if err != nil {
 			return nil, err
 		}
+
 		nodeIDs[i] = nodeID
 		valPubKeys[i] = pubKey