Add hashOracle utility hash function

Author: pkcs8

packages/xrpl/src/utils/hashes/README.md

@@ -60,6 +60,10 @@ Compute the hash of a ledger.
 
 Compute the hash of an escrow, given the owner's classic address (starting with `r`) and the account sequence number of the `EscrowCreate` escrow transaction.
 
+### hashOracle = (address, documentId): string
+
+Compute the hash of an oracle, given the owner's classic address (starting with `r`) and the OracleDocumentID of the `OracleSet` transaction.
+
 ### hashPaymentChannel = (address, dstAddress, sequence): string
 
 Compute the hash of a payment channel, given the owner's classic address (starting with `r`), the classic address of the destination, and the account sequence number of the `PaymentChannelCreate` payment channel transaction.

packages/xrpl/src/utils/hashes/index.ts

@@ -163,6 +163,22 @@ export function hashEscrow(address: string, sequence: number): string {
   )
 }
 
+/**
+ * Compute the Hash of an Oracle LedgerEntry.
+ *
+ * @param address - Address of the owner of the Oracle.
+ * @param documentId - OracleDocumentID of the Oracle.
+ * @returns The hash of the Oracle LedgerEntry.
+ * @category Utilities
+ */
+export function hashOracle(address: string, documentId: number): string {
+  return sha512Half(
+    ledgerSpaceHex('oracle') +
+      addressToHex(address) +
+      documentId.toString(HEX).padStart(BYTE_LENGTH * 2, '0'),
+  )
+}
+
 /**
  * Compute the hash of a Payment Channel.
  *

packages/xrpl/src/utils/hashes/ledgerSpaces.ts

@@ -17,6 +17,7 @@ const ledgerSpaces = {
   offer: 'o',
   // Directory of things owned by an account.
   ownerDir: 'O',
+  oracle: 'R',
   // Directory of order books.
   bookDir: 'B',
   contract: 'c',

packages/xrpl/src/utils/index.ts

@@ -45,6 +45,7 @@ import {
   hashLedger,
   hashLedgerHeader,
   hashEscrow,
+  hashOracle,
   hashPaymentChannel,
 } from './hashes'
 import parseNFTokenID from './parseNFTokenID'
@@ -178,6 +179,7 @@ const hashes = {
   hashLedger,
   hashLedgerHeader,
   hashEscrow,
+  hashOracle,
   hashPaymentChannel,
 }
 

packages/xrpl/test/utils/hashes.test.ts

@@ -16,6 +16,7 @@ import {
   hashTxTree,
   hashTrustline,
   hashEscrow,
+  hashOracle,
   hashPaymentChannel,
   hashSignedTx,
   hashAccountRoot,
@@ -138,6 +139,16 @@ describe('Hashes', function () {
     assert.equal(actualEntryHash, expectedEntryHash)
   })
 
+  it('calcOracleEntryHash', function () {
+    const account = 'rsNvoAZ9MquZSRhu4cEY9wTv1VqHXpVPPt'
+    const documentId = 1
+    const expectedEntryHash =
+      'D463D13ACF77206306BE891DF410655213FBD2C1F2B58A492E7F556A41A44338'
+    const actualEntryHash = hashOracle(account, documentId)
+
+    assert.equal(actualEntryHash, expectedEntryHash)
+  })
+
   it('calcPaymentChannelEntryHash', function () {
     const account = 'rDx69ebzbowuqztksVDmZXjizTd12BVr4x'
     const dstAccount = 'rLFtVprxUEfsH54eCWKsZrEQzMDsx1wqso'