Dev ii

backend/.env.example

@@ -7,10 +7,6 @@ NGROK_URL=
 # For ngrok testing, set your ngrok URL here (e.g., https://abc123.ngrok-free.app)
 # NGROK_URL=https://your-ngrok-url.ngrok-free.app
 
-# ── Active chain ──────────────────────────────────────────────────────────────
-# Set to "base" or "celo" to select which chain the backend operates on.
-ACTIVE_CHAIN=base
-
 # ── Shared ────────────────────────────────────────────────────────────────────
 BACKEND_PRIVATE_KEY=0x...
 ADMIN_SECRET=change-me-in-production

backend/src/__tests__/chain.service.spec.ts

@@ -37,14 +37,19 @@ vi.mock('@/utils/logger.ts', () => ({
 
 // Mock chain config - use a simple implementation
 vi.mock('../config/chains.ts', () => ({
-  getActiveChainConfig: vi.fn(() => ({
-    chainId: 8453,
-    label: 'Base',
-    rpcUrl: 'https://test-rpc.example.com',
-    contractAddress: '0x2222222222222222222222222222222222222222',
-    usdcAddress: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913',
-    explorerUrl: 'https://basescan.org',
-  })),
+  getChainConfig: vi.fn((chainId: number) => {
+    if (chainId === 8453) {
+      return {
+        chainId: 8453,
+        label: 'Base',
+        rpcUrl: 'https://test-rpc.example.com',
+        contractAddress: '0x2222222222222222222222222222222222222222',
+        usdcAddress: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913',
+        explorerUrl: 'https://basescan.org',
+      };
+    }
+    throw new Error(`Unknown chain: ${chainId}`);
+  }),
 }));
 
 describe('ChainService', () => {
@@ -60,7 +65,6 @@ describe('ChainService', () => {
     originalEnv = { ...process.env };
 
     // Set required env vars
-    process.env.ACTIVE_CHAIN = 'base';
     process.env.BASE_RPC_URL = 'https://test-rpc.example.com';
     process.env.BACKEND_PRIVATE_KEY =
       '0x1111111111111111111111111111111111111111111111111111111111111111';
@@ -97,8 +101,8 @@ describe('ChainService', () => {
   });
 
   describe('constructor', () => {
-    it('should initialize with environment variables', () => {
-      const service = new ChainService();
+    it('should initialize with chainId parameter', () => {
+      const service = new ChainService(8453);
 
       expect(ethers.JsonRpcProvider).toHaveBeenCalledWith(
         'https://test-rpc.example.com'
@@ -117,21 +121,25 @@ describe('ChainService', () => {
       expect(service.contract).toBe(mockContract);
     });
 
+    it('should throw error if chainId is not provided', () => {
+      expect(() => new ChainService(undefined as any)).toThrow();
+    });
+
     it('should throw error if BACKEND_PRIVATE_KEY is missing', () => {
       delete process.env.BACKEND_PRIVATE_KEY;
 
-      expect(() => new ChainService()).toThrow(/BACKEND_PRIVATE_KEY/);
+      expect(() => new ChainService(8453)).toThrow(/BACKEND_PRIVATE_KEY/);
     });
 
     it('should throw error if BASE_AVIATOR_CONTRACT_ADDRESS is missing', () => {
-      // Skipping this test as it requires complex mocking of getActiveChainConfig
+      // Skipping this test as it requires complex mocking of getChainConfig
       // which causes circular dependency issues. The actual error handling is tested
       // in integration tests.
       expect(true).toBe(true);
     });
 
-    it('should throw error if ACTIVE_CHAIN is unknown', () => {
-      // Skipping this test as it requires complex mocking of getActiveChainConfig
+    it('should throw error if chain is unknown', () => {
+      // Skipping this test as it requires complex mocking of getChainConfig
       // which causes circular dependency issues. The actual error handling is tested
       // in integration tests.
       expect(true).toBe(true);
@@ -142,7 +150,7 @@ describe('ChainService', () => {
     let chainService: ChainService;
 
     beforeEach(() => {
-      chainService = new ChainService();
+      chainService = new ChainService(8453);
     });
 
     it('should handle empty player arrays (no submission)', async () => {
@@ -294,7 +302,7 @@ describe('ChainService', () => {
     let chainService: ChainService;
 
     beforeEach(() => {
-      chainService = new ChainService();
+      chainService = new ChainService(8453);
     });
 
     it('should convert amount to USDC units (6 decimals)', async () => {
@@ -356,7 +364,7 @@ describe('ChainService', () => {
     let chainService: ChainService;
 
     beforeEach(() => {
-      chainService = new ChainService();
+      chainService = new ChainService(8453);
     });
 
     it('should scale multiplier correctly (× 100)', async () => {

backend/src/__tests__/game-engine.service.spec.ts

@@ -262,13 +262,19 @@ describe('GameEngine', () => {
       };
     });
 
+    it('should throw error when chainId is not provided', async () => {
+      await expect(gameEngine.placeBet('0x111', 50, undefined as any)).rejects.toThrow(
+        'chainId is required'
+      );
+    });
+
     it('should create bet in current round', async () => {
       const betData = { id: 1, address: '0x111', amount: 50 };
       mockBetRepo.create.mockReturnValue(betData);
       mockBetRepo.save.mockResolvedValue(betData);
       mockRoundRepo.save.mockResolvedValue({});
 
-      await gameEngine.placeBet('0x111', 50);
+      await gameEngine.placeBet('0x111', 50, 8453);
 
       expect(mockBetRepo.create).toHaveBeenCalledWith(
         expect.objectContaining({
@@ -283,23 +289,23 @@ describe('GameEngine', () => {
     it('should throw error when no active round', async () => {
       (gameEngine as any).currentRound = null;
 
-      await expect(gameEngine.placeBet('0x111', 50)).rejects.toThrow('Betting closed');
+      await expect(gameEngine.placeBet('0x111', 50, 8453)).rejects.toThrow('Betting closed');
     });
 
     it('should throw error during flying phase', async () => {
       (gameEngine as any).currentRound.phase = 'FLYING';
 
-      await expect(gameEngine.placeBet('0x111', 50)).rejects.toThrow('Betting closed');
+      await expect(gameEngine.placeBet('0x111', 50, 8453)).rejects.toThrow('Betting closed');
     });
 
     it('should validate bet amount (minimum)', async () => {
-      await expect(gameEngine.placeBet('0x111', 0.05)).rejects.toThrow(
+      await expect(gameEngine.placeBet('0x111', 0.05, 8453)).rejects.toThrow(
         'Invalid bet amount'
       );
     });
 
     it('should validate bet amount (maximum)', async () => {
-      await expect(gameEngine.placeBet('0x111', 1001)).rejects.toThrow(
+      await expect(gameEngine.placeBet('0x111', 1001, 8453)).rejects.toThrow(
         'Invalid bet amount'
       );
     });
@@ -310,7 +316,7 @@ describe('GameEngine', () => {
       mockBetRepo.save.mockResolvedValue(betData);
       mockRoundRepo.save.mockResolvedValue({});
 
-      await gameEngine.placeBet('0x111', 50);
+      await gameEngine.placeBet('0x111', 50, 8453);
 
       expect(mockRoundRepo.save).toHaveBeenCalledWith(
         expect.objectContaining({
@@ -325,7 +331,7 @@ describe('GameEngine', () => {
       mockBetRepo.save.mockResolvedValue(betData);
       mockRoundRepo.save.mockResolvedValue({});
 
-      await gameEngine.placeBet('0x111', 50);
+      await gameEngine.placeBet('0x111', 50, 8453);
 
       expect(gameEngine.leaderboardService.updateFromBet).toHaveBeenCalledWith({
         address: '0x111',
@@ -353,6 +359,22 @@ describe('GameEngine', () => {
       };
     });
 
+    it('should throw error when chainId is not provided', async () => {
+      const bet = {
+        id: 1,
+        address: '0x111',
+        amount: 100,
+        cashedOut: false,
+        round: { id: 1 },
+      };
+
+      mockBetRepo.findOne.mockResolvedValue(bet);
+
+      await expect(gameEngine.cashOutById(1, undefined as any)).rejects.toThrow(
+        'chainId is required'
+      );
+    });
+
     it('should update bet with cashout data', async () => {
       const bet = {
         id: 1,
@@ -366,7 +388,7 @@ describe('GameEngine', () => {
       mockBetRepo.save.mockImplementation((b: any) => Promise.resolve(b));
       mockRoundRepo.save.mockResolvedValue({});
 
-      const result = await gameEngine.cashOutById(1);
+      const result = await gameEngine.cashOutById(1, 8453);
 
       expect(result.cashedOut).toBe(true);
       expect(result.cashoutMultiplier).toBe(2.5);
@@ -385,15 +407,15 @@ describe('GameEngine', () => {
       mockBetRepo.save.mockImplementation((b: any) => Promise.resolve(b));
       mockRoundRepo.save.mockResolvedValue({});
 
-      const result = await gameEngine.cashOutById(1);
+      const result = await gameEngine.cashOutById(1, 8453);
 
       expect(result.payout).toBe(250); // 100 * 2.5
     });
 
     it('should throw error when bet not found', async () => {
       mockBetRepo.findOne.mockResolvedValue(null);
 
-      await expect(gameEngine.cashOutById(999)).rejects.toThrow('Bet not found');
+      await expect(gameEngine.cashOutById(999, 8453)).rejects.toThrow('Bet not found');
     });
 
     it('should throw error for already cashed out bets', async () => {
@@ -407,7 +429,7 @@ describe('GameEngine', () => {
 
       mockBetRepo.findOne.mockResolvedValue(bet);
 
-      await expect(gameEngine.cashOutById(1)).rejects.toThrow('Already cashed out');
+      await expect(gameEngine.cashOutById(1, 8453)).rejects.toThrow('Already cashed out');
     });
 
     it('should throw error when not in flying phase', async () => {
@@ -423,7 +445,7 @@ describe('GameEngine', () => {
 
       mockBetRepo.findOne.mockResolvedValue(bet);
 
-      await expect(gameEngine.cashOutById(1)).rejects.toThrow('Cannot cash out now');
+      await expect(gameEngine.cashOutById(1, 8453)).rejects.toThrow('Cannot cash out now');
     });
 
     it('should update round totalPayouts', async () => {
@@ -439,7 +461,7 @@ describe('GameEngine', () => {
       mockBetRepo.save.mockImplementation((b: any) => Promise.resolve(b));
       mockRoundRepo.save.mockResolvedValue({});
 
-      await gameEngine.cashOutById(1);
+      await gameEngine.cashOutById(1, 8453);
 
       expect(mockRoundRepo.save).toHaveBeenCalledWith(
         expect.objectContaining({
@@ -461,7 +483,7 @@ describe('GameEngine', () => {
       mockBetRepo.save.mockImplementation((b: any) => Promise.resolve(b));
       mockRoundRepo.save.mockResolvedValue({});
 
-      await gameEngine.cashOutById(1);
+      await gameEngine.cashOutById(1, 8453);
 
       expect(gameEngine.leaderboardService.updateFromBet).toHaveBeenCalledWith({
         address: '0x111',

backend/src/config/chains.ts

@@ -37,24 +37,17 @@ const CHAIN_REGISTRY: Record<string, BackendChainConfig> = {
 };
 
 /**
- * Returns the chain config for the active chain, determined by ACTIVE_CHAIN env var.
- * Defaults to "base" to preserve existing behaviour.
+ * Returns the chain config for a given chainId.
+ * If no chainId is provided, throws an error (chainId must be provided by frontend).
  */
-export function getActiveChainConfig(): BackendChainConfig {
-    const key = (process.env.ACTIVE_CHAIN || "base").toLowerCase();
-    const config = CHAIN_REGISTRY[key];
-    if (!config) {
+export function getActiveChainConfig(chainId?: number | string): BackendChainConfig {
+    if (!chainId) {
         throw new Error(
-            `Unknown ACTIVE_CHAIN="${key}". Supported values: ${Object.keys(CHAIN_REGISTRY).join(", ")}`
+            'chainId is required. The backend now uses the chain connected in the frontend. ' +
+            'Pass chainId in your request body or socket event.'
         );
     }
-    if (!config.contractAddress) {
-        throw new Error(
-            `Contract address not set for chain "${key}". ` +
-            `Set ${key.toUpperCase()}_AVIATOR_CONTRACT_ADDRESS in your .env`
-        );
-    }
-    return config;
+    return getChainConfig(chainId);
 }
 
 /**

backend/src/routes/admin.ts

@@ -30,7 +30,8 @@ const verifyAdmin = (req: Request, res: Response, next: () => void) => {
 // Helper to get chain service for a specific chain
 const getChainServiceForRequest = (req: Request): ChainService => {
   const chainId = req.body?.chainId || req.query?.chainId;
-  return new ChainService(chainId ? Number(chainId) : undefined);
+  const numChainId = chainId ? Number(chainId) : 8453; // Default to Base mainnet
+  return new ChainService(numChainId);
 };
 
 // GET /api/admin/house/balance - Get current house balance

backend/src/services/chain.service.ts

@@ -1,7 +1,7 @@
 import { ethers, type InterfaceAbi } from 'ethers';
 import { computePlayersMerkleRoot } from './merkle.js';
 import aviatorAbi from '../abi/aviator.json' with { type: 'json' };
-import { getActiveChainConfig, getChainConfig } from '../config/chains.js';
+import { getChainConfig } from '../config/chains.js';
 
 const aviatorAbiTyped = aviatorAbi as unknown as InterfaceAbi;
 import type { Round } from '../entities/round.entity.js';
@@ -14,8 +14,8 @@ export class ChainService {
   contract: ethers.Contract;
   chainId: number;
 
-  constructor(chainId?: number) {
-    const chainConfig = chainId ? getChainConfig(chainId) : getActiveChainConfig();
+  constructor(chainId: number) {
+    const chainConfig = getChainConfig(chainId);
     this.chainId = chainConfig.chainId;
     const key = process.env.BACKEND_PRIVATE_KEY;