refactor(sdk-coin-apt): delegation pool transaction subclass

Ticket: SC-3600
Ticket: SC-3601

First, we isolate `recipients` concept to transfer-based transactions.
For delegation pool operations, the transaction sender is not always
correlated with inputs and outputs (e.g. withdraw).

Then we create delegation pool-based transactions with
`validatorAddress` and `amount`.

Author: haritkapadia

modules/sdk-coin-apt/src/lib/iface.ts

@@ -17,7 +17,7 @@ export interface TxData {
   id: string;
   sender: string;
   /** @deprecated - use `recipients`. */
-  recipient: TransactionRecipient;
+  recipient?: TransactionRecipient;
   recipients: TransactionRecipient[];
   sequenceNumber: number;
   maxGasAmount: number;
@@ -28,6 +28,14 @@ export interface TxData {
   assetId: string;
 }
 
+/**
+ * The transaction data returned from the toJson() function of a delegation pool transaction
+ */
+export interface DelegationPoolTxData extends TxData {
+  validatorAddress: string | null;
+  amount: string | null;
+}
+
 export interface RecipientsValidationResult {
   recipients: {
     deserializedAddresses: string[];

modules/sdk-coin-apt/src/lib/transaction/abstractDelegationPoolAmountBasedTransaction.ts

@@ -0,0 +1,70 @@
+import {
+  AccountAddress,
+  EntryFunctionABI,
+  InputGenerateTransactionPayloadData,
+  MoveFunctionId,
+  TransactionPayload,
+  TransactionPayloadEntryFunction,
+  TypeTagAddress,
+  TypeTagU64,
+} from '@aptos-labs/ts-sdk';
+import { AbstractDelegationPoolTransaction } from './abstractDelegationPoolTransaction';
+import { BaseCoin } from '@bitgo/statics';
+import { InvalidTransactionError } from '@bitgo/sdk-core';
+import utils from '../utils';
+import { APTOS_COIN } from '../constants';
+
+/**
+ * This is a convenience class for delegation pool functions with arguments [address, amount].
+ *
+ * Assume this class can be deleted at any time (concrete implementations remain the same).
+ * Therefore, do not store objects as this type.
+ * Good: `export abstract class DelegationPoolWithdrawTransaction extends AbstractDelegationPoolAmountBasedTransaction`
+ * Good: `const transaction: AbstractDelegationPoolTransaction = DelegationPoolWithdrawTransaction()`
+ * Bad: `const transaction: AbstractDelegationPoolAmountBasedTransaction = DelegationPoolWithdrawTransaction()`
+ */
+export abstract class AbstractDelegationPoolAmountBasedTransaction extends AbstractDelegationPoolTransaction {
+  constructor(coinConfig: Readonly<BaseCoin>) {
+    super(coinConfig);
+    this._assetId = APTOS_COIN;
+  }
+
+  abstract moveFunctionId(): MoveFunctionId;
+
+  protected override parseTransactionPayload(payload: TransactionPayload): void {
+    if (!this.isValidPayload(payload)) {
+      throw new InvalidTransactionError('Invalid transaction payload');
+    }
+    const { entryFunction } = payload;
+    const addressArg = entryFunction.args[0];
+    const amountArg = entryFunction.args[1];
+    const [{ address, amount }] = utils.parseRecipients(addressArg, amountArg);
+    this.validatorAddress = address;
+    this.amount = amount.toString();
+  }
+
+  protected override getTransactionPayloadData(): InputGenerateTransactionPayloadData {
+    const { validatorAddress, amount } = this;
+    if (validatorAddress === undefined) throw new Error('validatorAddress is undefined');
+    if (amount === undefined) throw new Error('amount is undefined');
+    return {
+      function: this.moveFunctionId(),
+      typeArguments: [],
+      functionArguments: [AccountAddress.fromString(validatorAddress), amount],
+      abi: this.abi,
+    };
+  }
+
+  private isValidPayload(payload: TransactionPayload): payload is TransactionPayloadEntryFunction {
+    return (
+      payload instanceof TransactionPayloadEntryFunction &&
+      payload.entryFunction.args.length === 2 &&
+      payload.entryFunction.type_args.length === 0
+    );
+  }
+
+  private abi: EntryFunctionABI = {
+    typeParameters: [],
+    parameters: [new TypeTagAddress(), new TypeTagU64()],
+  };
+}

modules/sdk-coin-apt/src/lib/transaction/abstractDelegationPoolTransaction.ts

@@ -0,0 +1,23 @@
+import { DelegationPoolTxData } from '../iface';
+import { Transaction } from './transaction';
+import { BaseCoin } from '@bitgo/statics';
+
+/**
+ * This is for transactions where one delegator participates in a delegation pool.
+ */
+export abstract class AbstractDelegationPoolTransaction extends Transaction {
+  public validatorAddress?: string = undefined;
+  public amount?: string = undefined;
+
+  constructor(coinConfig: Readonly<BaseCoin>) {
+    super(coinConfig);
+  }
+
+  override toJson(): DelegationPoolTxData {
+    return {
+      ...super.toJson(),
+      validatorAddress: this.validatorAddress ?? null,
+      amount: this.amount ?? null,
+    };
+  }
+}

modules/sdk-coin-apt/src/lib/transaction/abstractTransferTransaction.ts

@@ -0,0 +1,37 @@
+import BigNumber from 'bignumber.js';
+import { InputsAndOutputs, Transaction } from './transaction';
+import { TxData } from '../iface';
+
+/**
+ * This is for transactions where one sender sends coins to recipients.
+ */
+export abstract class AbstractTransferTransaction extends Transaction {
+  override inputsAndOutputs(): InputsAndOutputs {
+    const totalAmount = this._recipients.reduce(
+      (accumulator, current) => accumulator.plus(current.amount),
+      new BigNumber('0')
+    );
+    const inputs = [
+      {
+        address: this.sender,
+        value: totalAmount.toString(),
+        coin: this._coinConfig.name,
+      },
+    ];
+    const outputs = this._recipients.map((recipient) => {
+      return {
+        address: recipient.address,
+        value: recipient.amount as string,
+        coin: this._coinConfig.name,
+      };
+    });
+    return { inputs, outputs, externalOutputs: this._recipients };
+  }
+
+  override toJson(): TxData {
+    return {
+      ...super.toJson(),
+      recipient: this.recipient,
+    };
+  }
+}

modules/sdk-coin-apt/src/lib/transaction/customTransaction.ts

@@ -1,31 +1,31 @@
-import { Transaction } from './transaction';
-import { BaseCoin as CoinConfig } from '@bitgo/statics';
-import { InvalidTransactionError, TransactionType } from '@bitgo/sdk-core';
 import {
   AccountAddress,
   EntryFunctionABI,
   EntryFunctionArgumentTypes,
-  SimpleEntryFunctionArgumentTypes,
   InputGenerateTransactionPayloadData,
+  SimpleEntryFunctionArgumentTypes,
   TransactionPayload,
   TransactionPayloadEntryFunction,
   TypeTagAddress,
   TypeTagBool,
-  TypeTagU8,
+  TypeTagU128,
   TypeTagU16,
+  TypeTagU256,
   TypeTagU32,
   TypeTagU64,
-  TypeTagU128,
-  TypeTagU256,
+  TypeTagU8,
 } from '@aptos-labs/ts-sdk';
+import { InvalidTransactionError, TransactionType } from '@bitgo/sdk-core';
+import { BaseCoin as CoinConfig } from '@bitgo/statics';
 import { CustomTransactionParams } from '../iface';
-import { validateModuleName, validateFunctionName } from '../utils/validation';
 import utils from '../utils';
+import { validateFunctionName, validateModuleName } from '../utils/validation';
+import { AbstractTransferTransaction } from './abstractTransferTransaction';
 
 /**
  * Transaction class for custom Aptos transactions.
  */
-export class CustomTransaction extends Transaction {
+export class CustomTransaction extends AbstractTransferTransaction {
   private _moduleName: string;
   private _functionName: string;
   private _typeArguments: string[] = [];

modules/sdk-coin-apt/src/lib/transaction/delegationPoolAddStakeTransaction.ts

@@ -1,55 +1,47 @@
-import { Transaction } from './transaction';
-import { InvalidTransactionError, TransactionType } from '@bitgo/sdk-core';
-import {
-  AccountAddress,
-  EntryFunctionABI,
-  InputGenerateTransactionPayloadData,
-  TransactionPayload,
-  TransactionPayloadEntryFunction,
-  TypeTagAddress,
-  TypeTagU64,
-} from '@aptos-labs/ts-sdk';
+import { MoveFunctionId } from '@aptos-labs/ts-sdk';
+import { TransactionType } from '@bitgo/sdk-core';
 
 import { BaseCoin as CoinConfig } from '@bitgo/statics';
-import { APTOS_COIN, DELEGATION_POOL_ADD_STAKE_FUNCTION } from '../constants';
-import utils from '../utils';
+import { DELEGATION_POOL_ADD_STAKE_FUNCTION } from '../constants';
+import { AbstractDelegationPoolAmountBasedTransaction } from './abstractDelegationPoolAmountBasedTransaction';
+import { InputsAndOutputs } from './transaction';
 
-export class DelegationPoolAddStakeTransaction extends Transaction {
+export class DelegationPoolAddStakeTransaction extends AbstractDelegationPoolAmountBasedTransaction {
   constructor(coinConfig: Readonly<CoinConfig>) {
     super(coinConfig);
     this._type = TransactionType.StakingDelegate;
-    this._assetId = APTOS_COIN;
   }
 
-  protected parseTransactionPayload(payload: TransactionPayload): void {
-    if (!this.isValidPayload(payload)) {
-      throw new InvalidTransactionError('Invalid transaction payload');
-    }
-    const { entryFunction } = payload;
-    const addressArg = entryFunction.args[0];
-    const amountArg = entryFunction.args[1];
-    this.recipients = utils.parseRecipients(addressArg, amountArg);
+  override moveFunctionId(): MoveFunctionId {
+    return DELEGATION_POOL_ADD_STAKE_FUNCTION;
   }
 
-  protected getTransactionPayloadData(): InputGenerateTransactionPayloadData {
+  override inputsAndOutputs(): InputsAndOutputs {
+    const { sender, validatorAddress, amount } = this;
+    if (sender === undefined) throw new Error('sender is undefined');
+    if (validatorAddress === undefined) throw new Error('validatorAddress is undefined');
+    if (amount === undefined) throw new Error('amount is undefined');
     return {
-      function: DELEGATION_POOL_ADD_STAKE_FUNCTION,
-      typeArguments: [],
-      functionArguments: [AccountAddress.fromString(this.recipients[0].address), this.recipients[0].amount],
-      abi: this.abi,
+      inputs: [
+        {
+          address: sender,
+          value: amount,
+          coin: this._coinConfig.name,
+        },
+      ],
+      outputs: [
+        {
+          address: validatorAddress,
+          value: amount,
+          coin: this._coinConfig.name,
+        },
+      ],
+      externalOutputs: [
+        {
+          address: validatorAddress,
+          amount: amount,
+        },
+      ],
     };
   }
-
-  private isValidPayload(payload: TransactionPayload): payload is TransactionPayloadEntryFunction {
-    return (
-      payload instanceof TransactionPayloadEntryFunction &&
-      payload.entryFunction.args.length === 2 &&
-      payload.entryFunction.type_args.length === 0
-    );
-  }
-
-  private abi: EntryFunctionABI = {
-    typeParameters: [],
-    parameters: [new TypeTagAddress(), new TypeTagU64()],
-  };
 }

modules/sdk-coin-apt/src/lib/transaction/digitalAssetTransfer.ts

@@ -1,4 +1,3 @@
-import { Transaction } from './transaction';
 import {
   AccountAddress,
   EntryFunctionABI,
@@ -14,12 +13,13 @@ import {
 import { InvalidTransactionError, TransactionRecipient, TransactionType } from '@bitgo/sdk-core';
 import { BaseCoin as CoinConfig } from '@bitgo/statics';
 import {
-  DIGITAL_ASSET_TYPE_ARGUMENT,
-  DIGITAL_ASSET_TRANSFER_FUNCTION,
   DIGITAL_ASSET_TRANSFER_AMOUNT,
+  DIGITAL_ASSET_TRANSFER_FUNCTION,
+  DIGITAL_ASSET_TYPE_ARGUMENT,
 } from '../constants';
+import { AbstractTransferTransaction } from './abstractTransferTransaction';
 
-export class DigitalAssetTransfer extends Transaction {
+export class DigitalAssetTransfer extends AbstractTransferTransaction {
   constructor(coinConfig: Readonly<CoinConfig>) {
     super(coinConfig);
     this._type = TransactionType.SendNFT;

modules/sdk-coin-apt/src/lib/transaction/fungibleAssetTransfer.ts

@@ -1,4 +1,3 @@
-import { Transaction } from './transaction';
 import {
   AccountAddress,
   EntryFunctionABI,
@@ -13,15 +12,16 @@ import {
 import { InvalidTransactionError, TransactionType } from '@bitgo/sdk-core';
 import { BaseCoin as CoinConfig } from '@bitgo/statics';
 import {
-  FUNGIBLE_ASSET_TYPE_ARGUMENT,
-  FUNGIBLE_ASSET_TRANSFER_FUNCTION,
-  FUNGIBLE_ASSET_BATCH_TRANSFER_FUNCTION,
-  FUNBIGLE_ASSET_TYPE_TAG,
   BATCH_FUNGIBLE_ASSET_TYPE_TAG,
+  FUNBIGLE_ASSET_TYPE_TAG,
+  FUNGIBLE_ASSET_BATCH_TRANSFER_FUNCTION,
+  FUNGIBLE_ASSET_TRANSFER_FUNCTION,
+  FUNGIBLE_ASSET_TYPE_ARGUMENT,
 } from '../constants';
 import utils from '../utils';
+import { AbstractTransferTransaction } from './abstractTransferTransaction';
 
-export class FungibleAssetTransfer extends Transaction {
+export class FungibleAssetTransfer extends AbstractTransferTransaction {
   constructor(coinConfig: Readonly<CoinConfig>) {
     super(coinConfig);
     this._type = TransactionType.SendToken;