feat!: prevent implicit asset burn

.changeset/wild-avocados-carry.md

@@ -0,0 +1,6 @@
+---
+"@fuel-ts/account": minor
+"@fuel-ts/errors": patch
+---
+
+feat!: prevent implicit asset burn

apps/docs/src/guide/errors/index.md

@@ -24,6 +24,12 @@ When an [`Account`](https://fuels-ts-docs-api.vercel.app/classes/_fuel_ts_accoun
 
 It could be caused during the deployments of contracts when an account is required to sign the transaction. This can be resolved by following the deployment guide [here](../contracts/deploying-contracts.md).
 
+### `ASSET_BURN_DETECTED`
+
+When you are trying to send a transaction that will result in an asset burn.
+
+Add relevant coin change outputs to the transaction, or enable asset burn in the transaction request.
+
 ### `CONFIG_FILE_NOT_FOUND`
 
 When a configuration file is not found. This could either be a `fuels.config.[ts,js,mjs,cjs]` file or a TOML file.

apps/docs/src/guide/transactions/snippets/transaction-request/asset-burn.ts

@@ -0,0 +1,39 @@
+import { InputType, Provider, ScriptTransactionRequest, Wallet } from 'fuels';
+import { ASSET_A } from 'fuels/test-utils';
+
+import { LOCAL_NETWORK_URL, WALLET_PVT_KEY } from '../../../../env';
+
+const provider = new Provider(LOCAL_NETWORK_URL);
+const sender = Wallet.fromPrivateKey(WALLET_PVT_KEY, provider);
+
+// #region asset-burn
+const transactionRequest = new ScriptTransactionRequest();
+
+const {
+  coins: [coin],
+} = await sender.getCoins(ASSET_A);
+
+// Add the coin as an input, without a change output
+transactionRequest.inputs.push({
+  id: coin.id,
+  type: InputType.Coin,
+  owner: coin.owner.toB256(),
+  amount: coin.amount,
+  assetId: coin.assetId,
+  txPointer: '0x00000000000000000000000000000000',
+  witnessIndex:
+    transactionRequest.getCoinInputWitnessIndexByOwner(coin.owner) ??
+    transactionRequest.addEmptyWitness(),
+});
+
+// Fund the transaction
+await transactionRequest.autoCost(sender);
+
+// Send the transaction with asset burn enabled
+const tx = await sender.sendTransaction(transactionRequest, {
+  enableAssetBurn: true,
+});
+// #endregion asset-burn
+
+const { isStatusSuccess } = await tx.waitForResult();
+console.log('Transaction should have been successful', isStatusSuccess);

apps/docs/src/guide/transactions/transaction-request.md

@@ -97,3 +97,11 @@ The transaction ID is a SHA-256 hash of the entire transaction request. This can
 <<< @./snippets/transaction-request/add-witness.ts#transaction-request-11{ts:line-numbers}
 
 > **Note**: Any changes made to a transaction request will alter the transaction ID. Therefore, you should only get the transaction ID after all modifications have been made.
+
+### Burning assets
+
+Assets can be burnt as part of a transaction that has inputs without associated output change. The SDK validates against this behavior, so we need to explicitly enable this by sending the transaction with the `enableAssetBurn` option set to `true`.
+
+<<< @./snippets/transaction-request/asset-burn.ts#asset-burn{ts:line-numbers}
+
+> **Note**: Burning assets is permanent and all assets burnt will be lost. Therefore, be mindful of the usage of this functionality.

packages/account/src/providers/provider.test.ts

@@ -1,11 +1,11 @@
-import { Address } from '@fuel-ts/address';
+import { Address, getRandomB256 } from '@fuel-ts/address';
 import { ZeroBytes32 } from '@fuel-ts/address/configs';
 import { randomBytes, randomUUID } from '@fuel-ts/crypto';
 import { FuelError, ErrorCode } from '@fuel-ts/errors';
 import { expectToThrowFuelError, safeExec } from '@fuel-ts/errors/test-utils';
 import { BN, bn } from '@fuel-ts/math';
 import type { Receipt } from '@fuel-ts/transactions';
-import { InputType, ReceiptType } from '@fuel-ts/transactions';
+import { InputType, OutputType, ReceiptType } from '@fuel-ts/transactions';
 import { DateTime, arrayify, sleep } from '@fuel-ts/utils';
 import { ASSET_A, ASSET_B } from '@fuel-ts/utils/test-utils';
 import { versions } from '@fuel-ts/versions';
@@ -34,7 +34,10 @@ import Provider, {
 } from './provider';
 import type { ExcludeResourcesOption } from './resource';
 import { isCoin } from './resource';
-import type { CoinTransactionRequestInput } from './transaction-request';
+import type {
+  ChangeTransactionRequestOutput,
+  CoinTransactionRequestInput,
+} from './transaction-request';
 import { CreateTransactionRequest, ScriptTransactionRequest } from './transaction-request';
 import { TransactionResponse } from './transaction-response';
 import type { SubmittedStatus } from './transaction-summary/types';
@@ -325,19 +328,27 @@ describe('Provider', () => {
   it('can call()', async () => {
     using launched = await setupTestProviderAndWallets();
     const { provider } = launched;
+    const owner = getRandomB256();
     const baseAssetId = await provider.getBaseAssetId();
 
     const CoinInputs: CoinTransactionRequestInput[] = [
       {
         type: InputType.Coin,
         id: '0xbc90ada45d89ec6648f8304eaf8fa2b03384d3c0efabc192b849658f4689b9c500',
-        owner: baseAssetId,
+        owner,
         assetId: baseAssetId,
         txPointer: '0x00000000000000000000000000000000',
         amount: 500_000,
         witnessIndex: 0,
       },
     ];
+    const ChangeOutputs: ChangeTransactionRequestOutput[] = [
+      {
+        type: OutputType.Change,
+        assetId: baseAssetId,
+        to: owner,
+      },
+    ];
     const transactionRequest = new ScriptTransactionRequest({
       tip: 0,
       gasLimit: 100_000,
@@ -352,6 +363,7 @@ describe('Provider', () => {
         arrayify('0x504000ca504400ba3341100024040000'),
       scriptData: randomBytes(32),
       inputs: CoinInputs,
+      outputs: ChangeOutputs,
       witnesses: ['0x'],
     });
 
@@ -2263,6 +2275,78 @@ Supported fuel-core version: ${mock.supportedVersion}.`
     expect(fetchChainAndNodeInfo).toHaveBeenCalledTimes(2);
   });
 
+  it('should throw error if asset burn is detected', async () => {
+    using launched = await setupTestProviderAndWallets();
+    const {
+      provider,
+      wallets: [sender],
+    } = launched;
+
+    const {
+      coins: [coin],
+    } = await sender.getCoins(ASSET_A);
+
+    const request = new ScriptTransactionRequest();
+
+    // Add the coin as an input, without a change output
+    request.inputs.push({
+      id: coin.id,
+      type: InputType.Coin,
+      owner: coin.owner.toB256(),
+      amount: coin.amount,
+      assetId: coin.assetId,
+      txPointer: '0x00000000000000000000000000000000',
+      witnessIndex:
+        request.getCoinInputWitnessIndexByOwner(coin.owner) ?? request.addEmptyWitness(),
+    });
+
+    const expectedErrorMessage = [
+      'Asset burn detected.',
+      'Add the relevant change outputs to the transaction to avoid burning assets.',
+      'Or enable asset burn, upon sending the transaction.',
+    ].join('\n');
+    await expectToThrowFuelError(
+      () => provider.sendTransaction(request),
+      new FuelError(ErrorCode.ASSET_BURN_DETECTED, expectedErrorMessage)
+    );
+  });
+
+  it('should allow asset burn if enabled', async () => {
+    using launched = await setupTestProviderAndWallets();
+    const {
+      provider,
+      wallets: [sender],
+    } = launched;
+    const {
+      coins: [coin],
+    } = await sender.getCoins(ASSET_A);
+
+    const request = new ScriptTransactionRequest();
+
+    // Add the coin as an input, without a change output
+    request.inputs.push({
+      id: coin.id,
+      type: InputType.Coin,
+      owner: coin.owner.toB256(),
+      amount: coin.amount,
+      assetId: coin.assetId,
+      txPointer: '0x00000000000000000000000000000000',
+      witnessIndex: request.getCoinInputWitnessIndexByOwner(sender) ?? request.addEmptyWitness(),
+    });
+
+    // Fund the transaction
+    await request.autoCost(sender);
+
+    const signedTransaction = await sender.signTransaction(request);
+    request.updateWitnessByOwner(sender.address, signedTransaction);
+
+    const response = await provider.sendTransaction(request, {
+      enableAssetBurn: true,
+    });
+    const { isStatusSuccess } = await response.waitForResult();
+    expect(isStatusSuccess).toBe(true);
+  });
+
   it('submits transaction and awaits status [success]', async () => {
     using launched = await setupTestProviderAndWallets();
     const {

packages/account/src/providers/provider.ts

@@ -49,6 +49,7 @@ import {
   isTransactionTypeCreate,
   isTransactionTypeScript,
   transactionRequestify,
+  validateTransactionForAssetBurn,
 } from './transaction-request';
 import type { TransactionResult, TransactionResultReceipt } from './transaction-response';
 import { TransactionResponse, getDecodedLogs } from './transaction-response';
@@ -363,7 +364,12 @@ export type ProviderCallParams = UTXOValidationParams & EstimateTransactionParam
 /**
  * Provider Send transaction params
  */
-export type ProviderSendTxParams = EstimateTransactionParams;
+export type ProviderSendTxParams = EstimateTransactionParams & {
+  /**
+   * Whether to enable asset burn for the transaction.
+   */
+  enableAssetBurn?: boolean;
+};
 
 /**
  * URL - Consensus Params mapping.
@@ -853,9 +859,11 @@ Supported fuel-core version: ${supportedVersion}.`
    */
   async sendTransaction(
     transactionRequestLike: TransactionRequestLike,
-    { estimateTxDependencies = true }: ProviderSendTxParams = {}
+    { estimateTxDependencies = true, enableAssetBurn }: ProviderSendTxParams = {}
   ): Promise<TransactionResponse> {
     const transactionRequest = transactionRequestify(transactionRequestLike);
+    validateTransactionForAssetBurn(transactionRequest, enableAssetBurn);
+
     if (estimateTxDependencies) {
       await this.estimateTxDependencies(transactionRequest);
     }

packages/account/src/providers/transaction-request/helpers.test.ts

@@ -1,7 +1,9 @@
 import { getRandomB256, Address } from '@fuel-ts/address';
 import { ZeroBytes32 } from '@fuel-ts/address/configs';
+import { ErrorCode, FuelError } from '@fuel-ts/errors';
+import { expectToThrowFuelError } from '@fuel-ts/errors/test-utils';
 import { bn } from '@fuel-ts/math';
-import { InputType } from '@fuel-ts/transactions';
+import { InputType, OutputType } from '@fuel-ts/transactions';
 
 import { generateFakeCoin, generateFakeMessageCoin } from '../../test-utils/resources';
 import {
@@ -20,7 +22,11 @@ import {
   getAssetAmountInRequestInputs,
   cacheRequestInputsResources,
   cacheRequestInputsResourcesFromOwner,
+  getBurnableAssetCount,
+  validateTransactionForAssetBurn,
 } from './helpers';
+import type { TransactionRequestInput } from './input';
+import type { TransactionRequestOutput } from './output';
 import { ScriptTransactionRequest } from './script-transaction-request';
 
 /**
@@ -196,5 +202,125 @@ describe('helpers', () => {
         expect(cached.messages).toStrictEqual([input3.nonce]);
       });
     });
+
+    describe('getBurnableAssetCount', () => {
+      it('should get the number of burnable assets [0]', () => {
+        const inputs: TransactionRequestInput[] = [
+          generateFakeRequestInputCoin({ assetId: ASSET_A, owner: owner.toB256() }),
+          generateFakeRequestInputCoin({ assetId: ASSET_B, owner: owner.toB256() }),
+        ];
+        const outputs: TransactionRequestOutput[] = [
+          { type: OutputType.Change, assetId: ASSET_A, to: owner.toB256() },
+          { type: OutputType.Change, assetId: ASSET_B, to: owner.toB256() },
+        ];
+        const expectedBurnableAssets = 0;
+
+        const burnableAssets = getBurnableAssetCount({ inputs, outputs });
+
+        expect(burnableAssets).toBe(expectedBurnableAssets);
+      });
+
+      it('should get the number of burnable assets [1]', () => {
+        const inputs: TransactionRequestInput[] = [
+          generateFakeRequestInputCoin({ assetId: ASSET_A, owner: owner.toB256() }),
+          generateFakeRequestInputCoin({ assetId: ASSET_B, owner: owner.toB256() }),
+        ];
+        const outputs: TransactionRequestOutput[] = [
+          { type: OutputType.Change, assetId: ASSET_A, to: owner.toB256() },
+        ];
+        const expectedBurnableAssets = 1;
+
+        const burnableAssets = getBurnableAssetCount({ inputs, outputs });
+
+        expect(burnableAssets).toBe(expectedBurnableAssets);
+      });
+
+      it('should get the number of burnable assets [2]', () => {
+        const inputs: TransactionRequestInput[] = [
+          generateFakeRequestInputCoin({ assetId: ASSET_A, owner: owner.toB256() }),
+          generateFakeRequestInputCoin({ assetId: ASSET_B, owner: owner.toB256() }),
+        ];
+        const outputs: TransactionRequestOutput[] = [];
+        const expectedBurnableAssets = 2;
+
+        const burnableAssets = getBurnableAssetCount({ inputs, outputs });
+
+        expect(burnableAssets).toBe(expectedBurnableAssets);
+      });
+    });
+
+    describe('validateTransactionForAssetBurn', () => {
+      it('should successfully validate transactions without burnable assets [enableAssetBurn=false]', () => {
+        const inputs: TransactionRequestInput[] = [
+          generateFakeRequestInputCoin({ assetId: ASSET_A, owner: owner.toB256() }),
+          generateFakeRequestInputCoin({ assetId: ASSET_B, owner: owner.toB256() }),
+        ];
+        const outputs: TransactionRequestOutput[] = [
+          { type: OutputType.Change, assetId: ASSET_A, to: owner.toB256() },
+          { type: OutputType.Change, assetId: ASSET_B, to: owner.toB256() },
+        ];
+        const enableAssetBurn = false;
+
+        expect(() =>
+          validateTransactionForAssetBurn({ inputs, outputs }, enableAssetBurn)
+        ).not.toThrow();
+      });
+
+      it('should throw an error if transaction has burnable assets [enableAssetBurn=false]', async () => {
+        const inputs: TransactionRequestInput[] = [
+          generateFakeRequestInputCoin({ assetId: ASSET_A, owner: owner.toB256() }),
+          generateFakeRequestInputCoin({ assetId: ASSET_B, owner: owner.toB256() }),
+        ];
+        const outputs: TransactionRequestOutput[] = [
+          { type: OutputType.Change, assetId: ASSET_A, to: owner.toB256() },
+        ];
+        const enableAssetBurn = false;
+
+        await expectToThrowFuelError(
+          () => validateTransactionForAssetBurn({ inputs, outputs }, enableAssetBurn),
+          new FuelError(
+            ErrorCode.ASSET_BURN_DETECTED,
+            [
+              `Asset burn detected.`,
+              `Add the relevant change outputs to the transaction to avoid burning assets.`,
+              `Or enable asset burn, upon sending the transaction.`,
+            ].join('\n')
+          )
+        );
+      });
+
+      it('should successfully validate transactions with burnable assets [enableAssetBurn=true]', () => {
+        const inputs: TransactionRequestInput[] = [
+          generateFakeRequestInputCoin({ assetId: ASSET_A, owner: owner.toB256() }),
+          generateFakeRequestInputCoin({ assetId: ASSET_B, owner: owner.toB256() }),
+        ];
+        const outputs: TransactionRequestOutput[] = [];
+        const enableAssetBurn = true;
+
+        expect(() =>
+          validateTransactionForAssetBurn({ inputs, outputs }, enableAssetBurn)
+        ).not.toThrow();
+      });
+
+      it('should validate asset burn by default [enableAssetBurn=undefined]', async () => {
+        const inputs: TransactionRequestInput[] = [
+          generateFakeRequestInputCoin({ assetId: ASSET_A, owner: owner.toB256() }),
+          generateFakeRequestInputCoin({ assetId: ASSET_B, owner: owner.toB256() }),
+        ];
+        const outputs: TransactionRequestOutput[] = [];
+
+        await expectToThrowFuelError(
+          () => validateTransactionForAssetBurn({ inputs, outputs }),
+          new FuelError(
+            ErrorCode.ASSET_BURN_DETECTED,
+            [
+              `Asset burn detected.`,
+              `Add the relevant change outputs to the transaction to avoid burning assets.`,
+              `Or enable asset burn, upon sending the transaction.`,
+            ].join('\n')
+          )
+        );
+      });
+    });
   });
 });