Add tests for oracle freshness check (stale data)

[Levi-Ojukwu]

Description:

The oracle freshness check in fund_invoice needs tests for stale data scenarios.

Why it matters: Stale oracle data is a security risk that could allow funding of unverified payers.

Acceptance Criteria:

• Test fund_invoice rejection when oracle data is stale
• Test fund_invoice success when oracle data is fresh
• Test with max_oracle_age_ledgers = 0 (check disabled)
• Test with no oracle configured (fail-open)

Relevant Files: contracts/invoice_liquidity/src/tests_oracle_freshness.rs

---

[jchinedu]

I'm a Backend/Full Stack Engineer with experience building secure backend systems and writing comprehensive tests for critical business logic. This issue aligns well with my experience, and I understand the importance of validating oracle freshness since it directly impacts the security and integrity of the funding process. I'll add thorough test coverage for stale and fresh oracle data, disabled freshness checks, and the no-oracle scenario while ensuring the tests remain consistent with the project's existing patterns and conventions.

[ekwe7]

I will love to work on this project

[Ivenkili]

@Ivenkili has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

hey maintainer
i would lot to work on thid issue kindly assign

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

[cristianooR7]

@cristianooR7 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

hello maintainer, i'd lik to work on this

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[DeFiVC]

@DeFiVC has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I would love to work on this issue.

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

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Congratulations, @DeFiVC! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

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This issue has been completed by @DeFiVC as part of the Stellar Wave Program's 7th Wave 🥳

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