Add unit tests for XDR event decoder

[Miracle656]

Background

Wraith's XDR event decoder parses raw Soroban event data into structured transfer records (from, to, amount, token). This decoder runs on every ingested ledger — a bug here silently corrupts the transfer history for all users. It currently has zero test coverage.

What to build

Add Jest unit tests for the XDR decoding logic using fixture data from real Soroban events.

Key files

• src/decoder.ts — the XDR parsing function
• src/__tests__/decoder.test.ts — create this

Suggested execution

git checkout -b test/xdr-decoder-unit-tests

1. Capture 3–5 real Soroban transfer event XDR payloads from testnet (Stellar Laboratory or the Horizon events API)
2. Store them as fixtures in src/__tests__/fixtures/events.json
3. Write tests asserting correct from, to, amount, and contractId for each fixture
4. Write one test with malformed XDR — decoder should throw, not return undefined

Example commit message:
test(decoder): add unit tests for XDR Soroban event decoder with fixtures

Acceptance criteria

• At least 3 valid SAC transfer event fixtures tested
• Malformed XDR input throws (not silent failure)
• No live network calls in tests
• npm test green

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Drips Wave · Complexity: Medium · 150 points
Comment below to request assignment. PR must include Closes #[this issue].

[K1NGD4VID]

@K1NGD4VID has applied to work on this issue as part of the Stellar Wave Program's 4th wave.

Hi!
Please, assign me this issue. I’ve worked on similar XDR decoding and test setups before, so I can add fixture-based Jest tests, cover valid and malformed cases, and ensure reliable parsing without network calls. ETA: 3–4 hours

ℹ️ Repo Maintainers: To accept this application, review their application or assign @K1NGD4VID to this issue.

[drips-wave]

Congratulations, @K1NGD4VID! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on April 29, 2026.

🧑‍💻 @K1NGD4VID: 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

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🌊 Happy Wave 🌊

[drips-wave]

This issue has been marked as completed by a Drips Wave moderator for @K1NGD4VID as part of the Stellar Wave Program's 4th Wave 🥳

Moderator's reason: [Auto-assessed] The contributor successfully addressed the issue by adding comprehensive unit tests and fixtures for the XDR decoder. The PR was merged by the maintainer after a small request for cleanup was addressed, and it explicitly closes the issue.

😎 @K1NGD4VID: You earned 150 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here.

🧑‍💻 Repo maintainers: How'd the contributor do? Leave a review to share your experience working with them.

ℹ️ Note: This issue was marked complete via moderation. Points were issued even though the GitHub issue remains open.