fix: make serializeForEntryFunction backward-compatible with older Serializers (DVR-143)

CHANGELOG.md

@@ -6,6 +6,7 @@ All notable changes to the Aptos TypeScript SDK will be captured in this file. T
 
 ## Fixed
 
+- Fix `serializeAsBytes is not a function` error when wallet extensions (e.g. Petra) bundle an older SDK and serialize v6 transaction objects. Added `serializeEntryFunctionBytesCompat()` helper with runtime fallback to the pre-v6 `bcsToBytes()` + `serializeBytes()` pattern (DVR-143)
 - Fix simple function arguments for `Vector<Option<T>>` types: BCS-encoded values (e.g. `AccountAddress.ONE`) passed as elements of `vector<Option<address>>` are now automatically wrapped in `MoveOption` instead of throwing a type mismatch error
 - Resolve moderate security advisories in `confidential-assets` dev tooling by pinning transitive `file-type` and `yauzl` (via `@swc/cli` → `@xhmikosr/downloader`) to patched releases
 - Remove hardcoded `maxGasAmount: 2000` from e2e tests (Account Derivation APIs, WebAuthn submission) that caused `MAX_GAS_UNITS_BELOW_MIN_TRANSACTION_GAS_UNITS` failures after the on-chain minimum gas increase

src/bcs/serializable/movePrimitives.ts

@@ -21,7 +21,13 @@ import {
   MAX_I256_BIG_INT,
 } from "../consts";
 import { Deserializer } from "../deserializer";
-import { Serializable, Serializer, ensureBoolean, validateNumberInRange } from "../serializer";
+import {
+  Serializable,
+  Serializer,
+  ensureBoolean,
+  serializeEntryFunctionBytesCompat,
+  validateNumberInRange,
+} from "../serializer";
 import { TransactionArgument } from "../../transactions/instances/transactionArgument";
 import { AnyNumber, Uint16, Uint32, Uint8, Int8, Int16, Int32, ScriptTransactionArgumentVariants } from "../../types";
 
@@ -76,14 +82,14 @@ export class Bool extends Serializable implements TransactionArgument {
   /**
    * Serializes the current instance for use in an entry function by converting it to a byte sequence.
    * This allows the instance to be properly formatted for serialization in transactions.
-   * Uses the optimized serializeAsBytes method to reduce allocations.
+   * Uses serializeAsBytes when available, with a fallback for older Serializer versions.
    *
    * @param serializer - The serializer instance used to serialize the byte sequence.
    * @group Implementation
    * @category BCS
    */
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   /**
@@ -138,7 +144,7 @@ export class U8 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -174,7 +180,7 @@ export class U16 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -209,7 +215,7 @@ export class U32 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -247,7 +253,7 @@ export class U64 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -283,7 +289,7 @@ export class U128 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -319,7 +325,7 @@ export class U256 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -354,7 +360,7 @@ export class I8 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -390,7 +396,7 @@ export class I16 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -425,7 +431,7 @@ export class I32 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -463,7 +469,7 @@ export class I64 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -499,7 +505,7 @@ export class I128 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -535,7 +541,7 @@ export class I256 extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {

src/bcs/serializable/moveStructs.ts

@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 import { Bool, U128, U16, U256, U32, U64, U8, I8, I16, I32, I64, I128, I256 } from "./movePrimitives";
-import { Serializable, Serializer } from "../serializer";
+import { Serializable, Serializer, serializeEntryFunctionBytesCompat } from "../serializer";
 import { Deserializable, Deserializer } from "../deserializer";
 import { AnyNumber, HexInput, ScriptTransactionArgumentVariants } from "../../types";
 import { Hex } from "../../core/hex";
@@ -69,14 +69,14 @@ export class MoveVector<T extends Serializable & EntryFunctionArgument>
   /**
    * Serializes the current instance into a byte sequence suitable for entry functions.
    * This allows the data to be properly formatted for transmission or storage.
-   * Uses the optimized serializeAsBytes method to reduce allocations.
+   * Uses serializeAsBytes when available, with a fallback for older Serializer versions.
    *
    * @param serializer - The serializer instance used to serialize the byte sequence.
    * @group Implementation
    * @category BCS
    */
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   /**
@@ -493,7 +493,7 @@ export class MoveString extends Serializable implements TransactionArgument {
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   serializeForScriptFunction(serializer: Serializer): void {
@@ -530,7 +530,7 @@ export class MoveOption<T extends Serializable & EntryFunctionArgument>
   }
 
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   /**

src/bcs/serializer.ts

@@ -77,6 +77,25 @@ export abstract class Serializable {
   }
 }
 
+/**
+ * Serialize a Serializable value as length-prefixed bytes into a Serializer,
+ * with backwards compatibility for older Serializer implementations that lack
+ * the `serializeAsBytes` method. This is critical for cross-version compatibility
+ * when SDK objects built with a newer SDK are serialized by an older SDK's Serializer
+ * (e.g., wallet extensions bundling an older SDK version).
+ *
+ * @param serializer - The serializer to write into (may be from any SDK version).
+ * @param value - The Serializable value to serialize as bytes.
+ */
+export function serializeEntryFunctionBytesCompat(serializer: Serializer, value: Serializable): void {
+  if (typeof (serializer as { serializeAsBytes?: unknown }).serializeAsBytes === "function") {
+    serializer.serializeAsBytes(value);
+  } else {
+    const bcsBytes = value.bcsToBytes();
+    serializer.serializeBytes(bcsBytes);
+  }
+}
+
 /**
  * Minimum buffer growth increment to avoid too many small reallocations.
  */

src/core/accountAddress.ts

@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 import { bytesToHex, hexToBytes } from "@noble/hashes/utils";
-import { Serializable, Serializer } from "../bcs/serializer";
+import { Serializable, Serializer, serializeEntryFunctionBytesCompat } from "../bcs/serializer";
 import { Deserializer } from "../bcs/deserializer";
 import { ParsingError, ParsingResult } from "./common";
 import { TransactionArgument } from "../transactions/instances/transactionArgument";
@@ -240,14 +240,14 @@ export class AccountAddress extends Serializable implements TransactionArgument
   /**
    * Serializes the current instance into a byte sequence suitable for entry functions.
    * This allows for the proper encoding of data when interacting with entry functions in the blockchain.
-   * Uses the optimized serializeAsBytes method to reduce allocations.
+   * Uses serializeAsBytes when available, with a fallback for older Serializer versions.
    *
    * @param serializer - The serializer instance used to convert the data into bytes.
    * @group Implementation
    * @category Serialization
    */
   serializeForEntryFunction(serializer: Serializer): void {
-    serializer.serializeAsBytes(this);
+    serializeEntryFunctionBytesCompat(serializer, this);
   }
 
   /**