End to end test integration

[KAMALDEEN333]

Implemented End-to-End Integration Tests
📌 Overview
Gasless transaction flows involve multiple services, chains, and smart contract interactions. Without end-to-end (E2E) testing, regressions or failures in any component can go undetected, causing unreliable behavior for users.

This task introduces End-to-End Integration Tests to simulate the complete transaction pipeline and validate the reliability of gasless flows.

🎯 Objective
Build a system that:

Simulates full gasless transaction workflows from initiation to completion
Validates interactions across backend API, RPC providers, queue workers, and contracts
Detects potential failures, regressions, and edge cases
Ensures confidence before merging or deploying changes
🛠 Scope of Work
1️⃣ Test Workflow Design
Identify critical gasless transaction flows:

Transaction creation via API
Queuing in BullMQ
Worker execution and RPC interaction
Signature verification and relayer submission
Transaction completion and monitoring
Include failure scenarios:

RPC timeout or failure
Worker retry logic
Insufficient gas or revert errors
Signature expiration
2️⃣ Test Environment Setup
Isolated test environment:

Local blockchain or testnets (e.g., Hardhat, Ganache, Goerli)
Dockerized services for backend and workers
Mock RPC providers if needed
Database reset between test runs to ensure consistency

3️⃣ Test Implementation
Write automated E2E tests using preferred framework:

Jest with Supertest (API endpoints)
Hardhat / Ethers.js for contract interactions
Optional Playwright or Cypress for dashboard flows
Example test case:

test("Gasless transaction completes successfully", async () => {
const tx = await api.createTransaction({ merchantId, to, value });
await worker.processQueue();
const receipt = await blockchain.getTransactionReceipt(tx.hash);
expect(receipt.status).toBe(1);
});

closes #72

[KAMALDEEN333]

Hi @mijinummi pr has been sent kindly review

[KAMALDEEN333]

Hi @mijinummi conflict resolved