Small fixes in operation (#200)

* Small fixes in operation

* Move length encoding to Extrinsic

packages/api-observable/src/Base.ts

@@ -52,7 +52,7 @@ export default class ApiBase {
         try {
           const meta = await this._api.state.getMetadata().toPromise();
 
-          this._genesisHash = await this._api.state.getBlockHash(0).toPromise();
+          this._genesisHash = await this._api.chain.getBlockHash(0).toPromise();
           ApiBase.extrinsics = extrinsicsFromMeta(meta);
           ApiBase.storage = storageFromMeta(meta);
 

packages/types/src/Extrinsic.ts

@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the ISC license. See the LICENSE file for details.
 
+import u8aToHex from '@polkadot/util/u8a/toHex';
 import blake2Asu8a from '@polkadot/util-crypto/blake2/asU8a';
 
 import Bytes from './Bytes';
@@ -18,4 +19,12 @@ export default class Extrinsic extends Bytes {
       blake2Asu8a(this.toU8a(), 256)
     );
   }
+
+  toHex (): string {
+    return u8aToHex(this.toU8a());
+  }
+
+  toJSON (): any {
+    return this.toHex();
+  }
 }