fix Autofill validation of DeliverMax and Amount

packages/xrpl/HISTORY.md

@@ -4,6 +4,12 @@ Subscribe to [the **xrpl-announce** mailing list](https://groups.google.com/g/xr
 
 ## Unreleased Changes
 
+### Added
+* New util `areAmountsEqual` to check if 2 amounts are strictly equal
+
+### Fixed
+* `autofill` function in client not validating amounts correctly
+
 ## 4.1.0 (2024-12-23)
 
 ### Added

packages/xrpl/src/client/index.ts

@@ -47,6 +47,7 @@ import type {
   OnEventToListenerMap,
 } from '../models/methods/subscribe'
 import type { SubmittableTransaction } from '../models/transactions'
+import { areAmountsEqual } from '../models/transactions/common'
 import { setTransactionFlagsToNumber } from '../models/utils/flags'
 import {
   ensureClassicAddress,
@@ -699,7 +700,7 @@ class Client extends EventEmitter<EventTypes> {
       // eslint-disable-next-line @typescript-eslint/ban-ts-comment -- ignore type-assertions on the DeliverMax property
       // @ts-expect-error -- DeliverMax property exists only at the RPC level, not at the protocol level
       // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition -- This is a valid null check for Amount
-      if (tx.Amount != null && tx.Amount !== tx.DeliverMax) {
+      if (tx.Amount != null && !areAmountsEqual(tx.Amount, tx.DeliverMax)) {
         return Promise.reject(
           new ValidationError(
             'PaymentTransaction: Amount and DeliverMax fields must be identical when both are provided',

packages/xrpl/src/models/transactions/common.ts

@@ -1,5 +1,6 @@
 /* eslint-disable max-lines -- common utility file */
 import { HEX_REGEX } from '@xrplf/isomorphic/utils'
+import BigNumber from 'bignumber.js'
 import { isValidClassicAddress, isValidXAddress } from 'ripple-address-codec'
 import { TRANSACTION_TYPES } from 'ripple-binary-codec'
 
@@ -191,6 +192,46 @@ export function isAmount(amount: unknown): amount is Amount {
   )
 }
 
+/**
+ * Check if two amounts are equal.
+ *
+ * @param amount1 - The first amount to compare.
+ * @param amount2 - The second amount to compare.
+ * @returns Whether the two amounts are equal.
+ * @throws When the amounts are not valid.
+ */
+export function areAmountsEqual(amount1: unknown, amount2: unknown): boolean {
+  const isAmount1Invalid = !isAmount(amount1)
+  if (isAmount1Invalid || !isAmount(amount2)) {
+    throw new ValidationError(
+      `Amount: invalid field. Expected Amount but received ${JSON.stringify(
+        isAmount1Invalid ? amount1 : amount2,
+      )}`,
+    )
+  }
+
+  if (isString(amount1) && isString(amount2)) {
+    return new BigNumber(amount1).eq(amount2)
+  }
+
+  if (isIssuedCurrency(amount1) && isIssuedCurrency(amount2)) {
+    return (
+      amount1.currency === amount2.currency &&
+      amount1.issuer === amount2.issuer &&
+      new BigNumber(amount1.value).eq(amount2.value)
+    )
+  }
+
+  if (isMPTAmount(amount1) && isMPTAmount(amount2)) {
+    return (
+      amount1.mpt_issuance_id === amount2.mpt_issuance_id &&
+      new BigNumber(amount1.value).eq(amount2.value)
+    )
+  }
+
+  return false
+}
+
 /**
  * Verify the form and type of an XChainBridge at runtime.
  *

packages/xrpl/test/client/autofill.test.ts

@@ -6,6 +6,7 @@ import {
   EscrowFinish,
   Payment,
   Transaction,
+  IssuedCurrencyAmount,
 } from '../../src'
 import { ValidationError } from '../../src/errors'
 import rippled from '../fixtures/rippled'
@@ -98,6 +99,25 @@ describe('client.autofill', function () {
     assert.strictEqual('DeliverMax' in txResult, false)
   })
 
+  it('Validate Payment transaction API v2: Payment Transaction: identical DeliverMax and Amount fields using amount objects', async function () {
+    // @ts-expect-error -- DeliverMax is a non-protocol, RPC level field in Payment transactions
+    paymentTx.DeliverMax = {
+      currency: 'USD',
+      value: AMOUNT,
+      issuer: 'r9vbV3EHvXWjSkeQ6CAcYVPGeq7TuiXY2X',
+    }
+    paymentTx.Amount = {
+      currency: 'USD',
+      value: AMOUNT,
+      issuer: 'r9vbV3EHvXWjSkeQ6CAcYVPGeq7TuiXY2X',
+    }
+
+    const txResult = await testContext.client.autofill(paymentTx)
+
+    assert.strictEqual((txResult.Amount as IssuedCurrencyAmount).value, AMOUNT)
+    assert.strictEqual('DeliverMax' in txResult, false)
+  })
+
   it('Validate Payment transaction API v2: Payment Transaction: differing DeliverMax and Amount fields', async function () {
     // @ts-expect-error -- DeliverMax is a non-protocol, RPC level field in Payment transactions
     paymentTx.DeliverMax = '6789'
@@ -106,6 +126,22 @@ describe('client.autofill', function () {
     await assertRejects(testContext.client.autofill(paymentTx), ValidationError)
   })
 
+  it('Validate Payment transaction API v2: Payment Transaction: differing DeliverMax and Amount fields using objects', async function () {
+    // @ts-expect-error -- DeliverMax is a non-protocol, RPC level field in Payment transactions
+    paymentTx.DeliverMax = {
+      currency: 'USD',
+      value: '31415',
+      issuer: 'r9vbV3EHvXWjSkeQ6CAcYVPGeq7TuiXY2X',
+    }
+    paymentTx.Amount = {
+      currency: 'USD',
+      value: '27182',
+      issuer: 'r9vbV3EHvXWjSkeQ6CAcYVPGeq7TuiXY2X',
+    }
+
+    await assertRejects(testContext.client.autofill(paymentTx), ValidationError)
+  })
+
   it('should not autofill if fields are present', async function () {
     const tx: Transaction = {
       TransactionType: 'DepositPreauth',