Ensure assetId is handled correctly when addSignature is used (#6083)

* Ensure assetId is handled correctly when addSignature is used

* Adjust test to mirror real failure

* test empty input on GenericExtrinsicPayload

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

@@ -95,4 +95,22 @@ describe('ExtrinsicPayload', (): void => {
       '0x940600ffd7568e5f0a7eda67a82691ff379ac4bba4f9c9b859fe779b5d46363b61ad2db9e56c0703d148e25901007b000000dcd1346701ca8396496e52aa2785b1748deb6db09551b72159dcb3e08991025bde8f69eeb5e065e18c6950ff708d7e551f68dc9bf59a07c52367c0280f805ec7'
     );
   });
+
+  it('has a sane inspect of an empty value', (): void => {
+    const reg = new TypeRegistry();
+
+    reg.setSignedExtensions(fallbackExtensions.concat(['ChargeAssetTxPayment']));
+    expect(new ExtrinsicPayload(reg, undefined).inspect()).toEqual({
+      inner: [
+        { name: 'method', outer: [new Uint8Array()] },
+        { inner: undefined, 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: 'genesisHash', outer: [new Uint8Array(32)] },
+        { name: 'blockHash', outer: [new Uint8Array(32)] }
+      ]
+    });
+  });
 });

packages/types/src/extrinsic/ExtrinsicPayload.ts

@@ -39,6 +39,33 @@ const PREAMBLES = {
   general: 'ExtrinsicPayloadV5'
 };
 
+/**
+ * HACK: In order to change the assetId from `number | object` to HexString (While maintaining the true type ie Option<TAssetConversion>),
+ * to allow for easier generalization of the SignerPayloadJSON interface the below check is necessary. The ExtrinsicPayloadV4 class does not like
+ * a value passed in as an Option, and can't decode it properly. Therefore, we ensure to convert the following below, and then pass the option as a unwrapped
+ * JSON value.
+ *
+ * ref: https://github.com/polkadot-js/api/pull/5968
+ * ref: https://github.com/polkadot-js/api/pull/5967
+ */
+export function decodeAssetId (registry: Registry, payload?: ExtrinsicPayloadValue | Uint8Array | HexString) {
+  const maybeAsset = (payload as ExtrinsicPayloadValue)?.assetId;
+
+  if (maybeAsset && isHex(maybeAsset)) {
+    const assetId = registry.createType('TAssetConversion', hexToU8a(maybeAsset));
+
+    // we only want to adjust the payload if the hex passed has the option
+    if (maybeAsset === '0x00' || maybeAsset === '0x01' + assetId.toHex().slice(2)) {
+      return {
+        ...(payload as ExtrinsicPayloadValue),
+        assetId: assetId.toJSON()
+      };
+    }
+  }
+
+  return payload;
+}
+
 /** @internal */
 function decodeExtrinsicPayload (registry: Registry, value?: GenericExtrinsicPayload | ExtrinsicPayloadValue | Uint8Array | string, version = LATEST_EXTRINSIC_VERSION, preamble: Preamble = DEFAULT_PREAMBLE): ExtrinsicPayloadVx {
   if (value instanceof GenericExtrinsicPayload) {
@@ -46,32 +73,9 @@ function decodeExtrinsicPayload (registry: Registry, value?: GenericExtrinsicPay
   }
 
   const extVersion = version === 5 ? PREAMBLES[preamble] : VERSIONS[version] || VERSIONS[0];
+  const payload = decodeAssetId(registry, value as ExtrinsicPayloadValue);
 
-  /**
-   * HACK: In order to change the assetId from `number | object` to HexString (While maintaining the true type ie Option<TAssetConversion>),
-   * to allow for easier generalization of the SignerPayloadJSON interface the below check is necessary. The ExtrinsicPayloadV4 class does not like
-   * a value passed in as an Option, and can't decode it properly. Therefore, we ensure to convert the following below, and then pass the option as a unwrapped
-   * JSON value.
-   *
-   * ref: https://github.com/polkadot-js/api/pull/5968
-   * ref: https://github.com/polkadot-js/api/pull/5967
-   */
-  if (value && (value as ExtrinsicPayloadValue).assetId && isHex((value as ExtrinsicPayloadValue).assetId)) {
-    const assetId = registry.createType('TAssetConversion', hexToU8a((value as ExtrinsicPayloadValue).assetId));
-
-    // we only want to adjust the payload if the hex passed has the option
-    if ((value as ExtrinsicPayloadValue).assetId === '0x00' ||
-      (value as ExtrinsicPayloadValue).assetId === '0x01' + assetId.toHex().slice(2)) {
-      const adjustedPayload = {
-        ...(value as ExtrinsicPayloadValue),
-        assetId: assetId.toJSON()
-      };
-
-      return registry.createTypeUnsafe(extVersion, [adjustedPayload, { version }]);
-    }
-  }
-
-  return registry.createTypeUnsafe(extVersion, [value, { version }]);
+  return registry.createTypeUnsafe(extVersion, [payload, { version }]);
 }
 
 /**

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

@@ -38,24 +38,24 @@ describe('ExtrinsicPayload', (): void => {
     });
   });
 
-  it('correctly decodes assetId', () => {
-    const TEST_WITH_ASSET = {
-      address: '5DTestUPts3kjeXSTMyerHihn1uwMfLj8vU8sqF7qYrFabHE',
-      assetId: '0x0002043205011f' as `0x${string}`,
-      blockHash: '0xde8f69eeb5e065e18c6950ff708d7e551f68dc9bf59a07c52367c0280f805ec7',
-      era: '0x0703',
-      genesisHash: '0xdcd1346701ca8396496e52aa2785b1748deb6db09551b72159dcb3e08991025b',
-      method: '0x0600ffd7568e5f0a7eda67a82691ff379ac4bba4f9c9b859fe779b5d46363b61ad2db9e56c',
-      nonce: '0x00001234',
-      specVersion: 123,
-      tip: '0x00000000000000000000000000005678',
-      transactionVersion: '0x00'
+  it('Correctly decodes assetId', () => {
+    const TEST_VALUE = {
+      address: 'J97drEQy6sYPXf2D1uj1hJfeHsxjvwr4tVGKs9o8VDSht8r',
+      assetId: '0x010002043205011f' as `0x${string}`,
+      blockHash: '0x28a464e6b40fccec3b9e7989db97d2627d3653c644a3c801f8239910eaaa58a8',
+      era: '0x4401',
+      genesisHash: '0x48239ef607d7928874027a43a67689209727dfb3d3dc5e5b03a39bdc2eda771a',
+      method: '0x0a0300d27001b334c34489c67b81dfbbdc86eba5b433163bd08226d89b081914e9aa490284d717',
+      nonce: '0x0000000a',
+      specVersion: '0x000f4dfc',
+      tip: '0x00000000000000000000000000000000',
+      transactionVersion: '0x0000000f'
     };
 
     const reg = new TypeRegistry();
 
     reg.setSignedExtensions(fallbackExtensions.concat(['ChargeAssetTxPayment']));
-    const ext = new ExtrinsicPayload(reg, TEST_WITH_ASSET);
+    const ext = new ExtrinsicPayload(reg, TEST_VALUE);
 
     expect(ext.assetId.toJSON()).toEqual({
       interior: {

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

@@ -13,6 +13,7 @@ import type { ExtrinsicPayloadValue, ICompact, IKeyringPair, INumber, IOption }
 import { Enum, Struct } from '@polkadot/types-codec';
 import { objectSpread } from '@polkadot/util';
 
+import { decodeAssetId } from '../ExtrinsicPayload.js';
 import { sign } from '../util.js';
 
 /**
@@ -29,7 +30,7 @@ export class GenericExtrinsicPayloadV4 extends Struct {
       { method: 'Bytes' },
       registry.getSignedExtensionTypes(),
       registry.getSignedExtensionExtra()
-    ), value);
+    ), decodeAssetId(registry, value));
 
     // Do detection for the type of extrinsic, in the case of MultiSignature
     // this is an enum, in the case of AnySignature, this is a Hash only