Adjust inspect for ExtrinsicPayload (#4862)

* Adjust inspect for ExtrinsicPayload

* Adjust

packages/types/src/extrinsic/v4/ExtrinsicPayload.spec.ts

@@ -0,0 +1,35 @@
+// Copyright 2017-2022 @polkadot/types authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+import rpcMetadata from '@polkadot/types-support/metadata/static-substrate';
+
+import { TypeRegistry } from '../../create';
+import { decorateExtrinsics, Metadata } from '../../metadata';
+import { GenericExtrinsicPayloadV4 as ExtrinsicPayload } from '.';
+
+const registry = new TypeRegistry();
+const metadata = new Metadata(registry, rpcMetadata);
+
+registry.setMetadata(metadata);
+
+const tx = decorateExtrinsics(registry, metadata.asLatest, metadata.version);
+
+describe('ExtrinsicPayload', (): void => {
+  it('has a sane inspect', (): void => {
+    // we don't expect this to fail, however it is actually a good
+    // reference for the ordering in base Substrate
+    expect(new ExtrinsicPayload(registry, { method: tx.timestamp.set(0).toHex() } as never).inspect()).toEqual({
+      inner: [
+        { name: 'method', outer: [new Uint8Array([3, 0, 0])] },
+        { name: 'era', outer: [new Uint8Array([0]), new Uint8Array([0])] },
+        { name: 'nonce', outer: [new Uint8Array([0])] },
+        { name: 'tip', outer: [new Uint8Array([0])] },
+        { name: 'assetId', outer: [new Uint8Array([0])] },
+        { name: 'specVersion', outer: [new Uint8Array([0, 0, 0, 0])] },
+        { name: 'transactionVersion', outer: [new Uint8Array([0, 0, 0, 0])] },
+        { name: 'genesisHash', outer: [new Uint8Array(32)] },
+        { name: 'blockHash', outer: [new Uint8Array(32)] }
+      ]
+    });
+  });
+});

packages/types/src/extrinsic/v4/ExtrinsicPayload.ts

@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 import type { SignOptions } from '@polkadot/keyring/types';
-import type { Registry } from '@polkadot/types-codec/types';
+import type { Inspect, Registry } from '@polkadot/types-codec/types';
 import type { HexString } from '@polkadot/util/types';
 import type { ExtrinsicEra } from '../../interfaces/extrinsics';
 import type { Hash } from '../../interfaces/runtime';
@@ -37,6 +37,13 @@ export class GenericExtrinsicPayloadV4 extends Struct {
     };
   }
 
+  /**
+   * @description Returns a breakdown of the hex encoding for this Codec
+   */
+  public override inspect (): Inspect {
+    return super.inspect({ method: true });
+  }
+
   /**
    * @description The block [[Hash]] the signature applies to (mortal/immortal)
    */