support hexseed when creating keypair

Author: AlaaElattar

packages/signer/lib/src/sign.dart

@@ -30,10 +30,11 @@ class Signer {
     }
   }
 
-  void fromHexSeed(String hexSeed, KPType type) {
+  KeyPair? fromHexSeed(String hexSeed, KPType type) {
     try {
       final seed = HEX.decode(hexSeed.replaceAll('0x', ''));
       keypair = fromSeed(Uint8List.fromList(seed), type);
+      return keypair;
     } catch (e) {
       throw Exception("Failed to create keyPair from hex seed. Error: $e");
     }

packages/tfchain_client/lib/src/client.dart

@@ -174,12 +174,22 @@ class Client extends QueryClient {
     _checkInputs();
     final Signer.Signer signer = Signer.Signer();
     if (keypairType == "sr25519") {
-      keypair = await signer.fromMnemonic(
-          mnemonicOrSecretSeed, Signer.KPType.sr25519);
+      if (validateMnemonic(mnemonicOrSecretSeed)) {
+        keypair = await signer.fromMnemonic(
+            mnemonicOrSecretSeed, Signer.KPType.sr25519);
+      } else {
+        keypair = await signer.fromHexSeed(
+            mnemonicOrSecretSeed, Signer.KPType.sr25519);
+      }
       address = keypair!.address;
     } else {
-      keypair = await signer.fromMnemonic(
-          mnemonicOrSecretSeed, Signer.KPType.ed25519);
+      if (validateMnemonic(mnemonicOrSecretSeed)) {
+        keypair = await signer.fromMnemonic(
+            mnemonicOrSecretSeed, Signer.KPType.ed25519);
+      } else {
+        keypair = await signer.fromHexSeed(
+            mnemonicOrSecretSeed, Signer.KPType.ed25519);
+      }
       address = keypair!.address;
     }
   }