From 545e3dfb1ad15f723b0cf55f1bdf188cf7dc45ab Mon Sep 17 00:00:00 2001
From: NostrDev <support@nostrdev.com>
Date: Fri, 20 Dec 2024 15:32:52 +0100
Subject: [PATCH] #226 Update Project ID Derivation (#18)

* feat(mempool-ui): adds initial component files

* fix: interface importing

* chore: local dev setup

* adds angor ui components and interfaces

* feat(ui): adds blockchain view

* feature(angor-search): adds angor to search bar

* feat(ui): updates angor module structure

* feat(ui): adds pagination - part 1

* feat(ui): adds pagination to the list

* feat(ui): adds no-data skeleton

* fix: updates the project component

* fix: return empty array if no investments

* chore: restores local dev settings

* chore: removes redundant description

* fix: adds missed mock (#14)

* #144 - Extract NostrEventId instead Npub (#16)

* fix: updates signet challenge

* feat(eventId): initial commit

* feat(event-id): removes npub from query

* feat(eventId): updates unit tests

* fix: reverse order of projects

* feat(derivation): implements new derivation

* fix: removes uneeded import

* fix: removes unneeded import

* fix: restores back from local dev settings
---
 backend/src/angor/AngorTransactionDecoder.ts  |  5 +++--
 .../tests/AngorTransactionDecoder.test.ts     | 22 ++-----------------
 2 files changed, 5 insertions(+), 22 deletions(-)

diff --git a/backend/src/angor/AngorTransactionDecoder.ts b/backend/src/angor/AngorTransactionDecoder.ts
index 377f7905fe..2770b2bd84 100644
--- a/backend/src/angor/AngorTransactionDecoder.ts
+++ b/backend/src/angor/AngorTransactionDecoder.ts
@@ -357,8 +357,9 @@ export class AngorTransactionDecoder {
    * @returns an integer that is derived from integer representation of founder key hash.
    */
   private getProjectIdDerivation(founderKeyHashInt: number): number {
-    // The max size of bip32 derivation range is 2,147,483,648 (2^31) the max number of uint is 4,294,967,295 so we must to divide by 2 and round it to the floor.
-    const retention = Math.floor(founderKeyHashInt / 2);
+    const intMaxValue = 0x7FFFFFFF;
+
+    const retention = founderKeyHashInt & intMaxValue;
 
     if (retention > Math.pow(2, 31)) {
       throw new Error(
diff --git a/backend/src/angor/tests/AngorTransactionDecoder.test.ts b/backend/src/angor/tests/AngorTransactionDecoder.test.ts
index 29c6361874..92f5c96c9e 100644
--- a/backend/src/angor/tests/AngorTransactionDecoder.test.ts
+++ b/backend/src/angor/tests/AngorTransactionDecoder.test.ts
@@ -6,7 +6,6 @@ import {
 import * as bitcoinJS from 'bitcoinjs-lib';
 import AngorProjectRepository from '../../repositories/AngorProjectRepository';
 import AngorInvestmentRepository from '../../repositories/AngorInvestmentRepository';
-import DB from '../../database';
 
 describe('AngorTransactionDecoder', () => {
   describe('Decoding transaction for Angor project creation', () => {
@@ -18,8 +17,8 @@ describe('AngorTransactionDecoder', () => {
       founderKeyHashHex:
         '68828edc1c6312c915c8967475be57f42d45764105af8216f2da7170d033240a',
       founderKeyHashInt: 3493012490,
-      projectIdDeriviation: 1746506245,
-      projectId: 'angor1qzkfpckm2vnhdvfcwr7vdhwt7ns3rd95gr0age0',
+      projectIdDeriviation: 1345528842,
+      projectId: 'angor1quc59k4kt0nv62xhj72xtqfmzk55cexxmf6pkz7',
       nostrEventId: '0f2d8db8568bd3e12bdab1faa217fffc80459053967eff8bde0a65f14e2b7079',
       addressOnFeeOutput: 'tb1quc59k4kt0nv62xhj72xtqfmzk55cexxmae8lyc',
       txid: '0d28976a42bf7618ad9470cf0202e2eb06d6072e75e139eab012a160b7b480aa',
@@ -261,23 +260,6 @@ describe('AngorTransactionDecoder', () => {
           data.projectIdDeriviation
         );
       });
-
-      it('should throw an error if the retention is greater than 2 in power of 31', () => {
-        jest
-          .spyOn(angorDecoder as any, 'hashToInt')
-          .mockImplementation(() => Math.pow(2, 31) * 2 + 2);
-
-        const keyHash = angorDecoder['getKeyHash'](keyHex);
-        const keyHashInt = angorDecoder['hashToInt'](keyHash);
-
-        expect(() =>
-          angorDecoder['getProjectIdDerivation'](keyHashInt)
-        ).toThrow(
-          new Error(
-            `Retention is too large. The max number is 2^31 (2,147,483,648).`
-          )
-        );
-      });
     });
 
     describe('getProjectId', () => {