From e22c3464036f97eee3c617d3790aac35b3d95379 Mon Sep 17 00:00:00 2001
From: Dhruv Kelawala <dhruvrk2000@gmail.com>
Date: Wed, 15 Jun 2022 18:51:48 +0530
Subject: [PATCH] feat: add calculateContractAddressFromHash

---
 __tests__/utils/utils.test.ts | 25 +++++++++++++++++++++++++
 src/utils/hash.ts             | 24 +++++++++++++++++++++++-
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/__tests__/utils/utils.test.ts b/__tests__/utils/utils.test.ts
index decef618e..2d87385ed 100644
--- a/__tests__/utils/utils.test.ts
+++ b/__tests__/utils/utils.test.ts
@@ -1,6 +1,7 @@
 import fs from 'fs';
 
 import { constants, hash, json, number, stark } from '../../src';
+import { pedersen } from '../../src/utils/hash';
 
 const { IS_BROWSER } = constants;
 
@@ -87,3 +88,27 @@ describe('estimatedFeeToMaxFee()', () => {
     expect(res).toBe(11_500);
   });
 });
+
+describe('Deterministic Address calculation', () => {
+  // This test just show how to use calculateContractAddressFromHash for new devs
+
+  test.only('calculate hash', () => {
+    const ethAddress = '0x049d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7';
+
+    const daiAddress = '0x03e85bfbb8e2a42b7bead9e88e9a1b19dbccf661471061807292120462396ec9';
+    const factoryAddress = '0x249827618A01858A72B7D04339C47195A324D20D6037033DFE2829F98AFF4FC';
+    const classHash = '0x55187E68C60664A947048E0C9E5322F9BF55F7D435ECDCF17ED75724E77368F';
+
+    // Any type of salt can be used. It depends on the dApp what kind of salt it wants to use.
+    const salt = pedersen([ethAddress, daiAddress]);
+
+    const res = hash.calculateContractAddressFromHash(
+      salt,
+      classHash,
+      [ethAddress, daiAddress, factoryAddress],
+      factoryAddress
+    );
+
+    expect(res).not.toBeNull();
+  });
+});
diff --git a/src/utils/hash.ts b/src/utils/hash.ts
index 7df83cafd..5bcf02c6c 100644
--- a/src/utils/hash.ts
+++ b/src/utils/hash.ts
@@ -11,9 +11,10 @@ import {
   TransactionHashPrefix,
   ZERO,
 } from '../constants';
+import { RawCalldata } from '../types/lib';
 import { ec } from './ellipticCurve';
 import { addHexPrefix, buf2hex, utf8ToArray } from './encode';
-import { BigNumberish, toBN, toHex } from './number';
+import { BigNumberish, toBN, toFelt, toHex } from './number';
 
 export const transactionVersion = 0;
 export const feeTransactionVersion = toBN(2).pow(toBN(128)).add(toBN(transactionVersion));
@@ -132,3 +133,24 @@ export function calculcateTransactionHash(
     chainId
   );
 }
+
+export function calculateContractAddressFromHash(
+  salt: BigNumberish,
+  classHash: BigNumberish,
+  constructorCalldata: RawCalldata,
+  deployerAddress: BigNumberish
+) {
+  const constructorCalldataHash = computeHashOnElements(constructorCalldata);
+
+  const CONTRACT_ADDRESS_PREFIX = toFelt('0x535441524b4e45545f434f4e54524143545f41444452455353'); // Equivalent to 'STARKNET_CONTRACT_ADDRESS'
+
+  const dataToHash = [
+    CONTRACT_ADDRESS_PREFIX,
+    deployerAddress,
+    salt,
+    classHash,
+    constructorCalldataHash,
+  ];
+
+  return computeHashOnElements(dataToHash);
+}