[Testing] Offline Horizon RPC Mocking for Stellar SDK

[AlAfiz]

Description: Implement a robust HTTP mocking layer intercepting outbound requests from the @stellar/stellar-sdk to the Horizon RPC.
Context / Motivation: Running backend tests shouldn't require an active internet connection or rely on the rate-limited public testnet Horizon nodes. Offline mocking ensures our CI pipelines run blazingly fast and predictably.
Acceptance Criteria: - [ ] Integrate a mocking library like nock or msw (Mock Service Worker).

• Capture and store raw JSON responses from Horizon for standard calls (e.g., fetching account balances, fee stats).
• Configure the test suite to intercept SDK network calls and return these stored JSON fixtures instead.
• Write a test asserting that API handles a mocked 504 Gateway Timeout from Horizon gracefully.
  Technical Pointers: The Stellar SDK relies heavily on standard HTTP requests under the hood. You will need to explicitly mock the exact URL paths (e.g., https://horizon-testnet.stellar.org/accounts/...) that the server utilizes.

[whitezaddy]

I have experience for this and have reviewed the code; I can submit a PR within 2 days.

[Menjay7]

Hi! I came across this issue and would love to work on it. I have experience with similar tasks and I'm confident I can investigate, implement a clean solution, and thoroughly test it before submitting a PR. If the issue is still open, I would appreciate it if you could assign it to me. Thank you!

[clintjeff2]

Hello, I have 6 years of experience working on tasks like this and handling similar challenges across backend, frontend, and smart-contract development. I have carefully read and fully understood the task requirements, and I am confident I can deliver a clean, efficient, and well-tested solution promptly. I always ensure high-quality implementation, maintainability, and adherence to best practices.

Pull request in 5 hours.

[gloskull]

Hi, I would love to work on this Issue.
I have 4 years of experience delivering solutions for projects like this, covering backend, frontend, full-stack and smart contract development. After carefully reviewing your requirements, I have a clear understanding of the task and am confident in my ability to deliver a clean, efficient, and thoroughly tested solution on time. I prioritize code quality, maintainability, and industry best practices throughout the development process.
My PR will be submitted in under 10hours.

[gloskull]

Hi, I would love to work on this Issue.
I have 4 years of experience delivering solutions for projects like this, covering backend, frontend, full-stack and smart contract development. After carefully reviewing your requirements, I have a clear understanding of the task and am confident in my ability to deliver a clean, efficient, and thoroughly tested solution on time. I prioritize code quality, maintainability, and industry best practices throughout the development process.
My PR will be submitted in under 10hours.