Add `packages/test-utils/` shared testing utilities

[Levi-Ojukwu]

Description
The SDK, CLI, indexer, and notifications tests all need similar utilities: mock Stellar keypairs, mock contract responses, mock Horizon clients, and fake invoice data factories. Centralising these in a shared test-utils package eliminates duplication and makes tests easier to write.

Requirements and context

• Create packages/test-utils/src/ with:
  • mockKeypair() — generate deterministic test Stellar keypairs
  • mockInvoice(overrides?) — create fake Invoice objects
  • mockHorizonClient() — mock Horizon streaming and REST responses
  • mockContractResponse(method, result) — mock Soroban simulation responses
  • mockReputationScore(overrides?) — create fake reputation data
• Export everything from packages/test-utils/index.ts
• Each package in the monorepo should import from @invoice-liquidity/test-utils in tests

Suggested execution

git checkout -b feat/shared-test-utils

• Create packages/test-utils/ package
• Migrate duplicate mock utilities from each package's tests
• Update all affected test files to use the shared package

Example commit message
feat: add shared test-utils package with mock factories for all packages

[adepoju2006]

@adepoju2006 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I have experience building shared test utility packages for monorepos. I'll create packages/test-utils/src/ with mockKeypair(), mockInvoice(), and mockHorizonClient() helpers, centralizing common mocking patterns across SDK, CLI, indexer, and notification tests to eliminate duplication and make writing new tests significantly faster.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @adepoju2006 to this issue.

[Gabugo-tech]

@Gabugo-tech has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi Maintainers,

I'd like to take on this issue. I have experience working with monorepos, shared testing utilities, and test refactoring. I understand the goal is to centralize common mocks and factories into a reusable @invoice-liquidity/test-utils package and migrate existing tests to use it.

I'll ensure the utilities are deterministic, well-documented, easy to extend, and that all affected tests continue to pass after the migration.

Thanks for considering my assignment.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Gabugo-tech to this issue.

[Bellamzy]

@Bellamzy has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I'd really like the chance to work on this issue — I've been actively looking to contribute and gain real experience, and I have hands-on skills in debugging and GitHub workflows to back it up.
My plan: reproduce the problem, implement and test a clean fix, then open a focused PR for review.
This opportunity means a lot to me right now, and I'd put in the time to get it done right and quickly.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Bellamzy to this issue.

[attyolu]

@attyolu has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Good evening Maintainer. I would love to work on this issue quickly. Please assign to me. Thank you

ℹ️ Repo Maintainers: To accept this application, review their application or assign @attyolu to this issue.

[QwinDivy]

@QwinDivy has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi Maintainer, I'd love to take this one on. I've gone through the codebase and I'm comfortable with the approach needed here. I'll keep the change focused, add tests, and make sure CI stays green. Happy to open a draft early so we can align on direction.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @QwinDivy to this issue.

[Ultra-Tech-code]

@Ultra-Tech-code has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

hello, I'd like to work on this issue.

I'll create the shared packages/test-utils package with reusable testing utilities for the ILN monorepo. I'll add deterministic Stellar keypair generation, fake invoice and reputation score factories, mocked Horizon client helpers, and Soroban contract response mocks. I'll export the utilities through packages/test-utils/index.ts, migrate duplicated test helpers from existing packages, and update tests across the SDK, CLI, indexer, and notifications services to use @invoice-liquidity/test-utils.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Ultra-Tech-code to this issue.

[Caneryy]

@Caneryy has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi there, can I work on this issue?

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Caneryy to this issue.

[drips-wave]

Congratulations, @Ultra-Tech-code! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @Ultra-Tech-code: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊

[grantfox-oss]

🦊 GrantFox — @Ultra-Tech-code has been assigned to this issue!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #367)
2. Your PR will be reviewed by the Invoice-Liquidity-Network maintainers

Good luck! Track your progress on GrantFox.