[Cynthiaoma]

Overview

This PR migrates the XDR decoding paths from the legacy .switch() / accessor-call style to the discriminated-union types introduced in @stellar/stellar-sdk 17, so the indexer compiles and decodes contract data correctly on the bumped SDK. The changes are limited to the files that decode ledger entries and ScVals, plus a new test for SAC detection.

Related Issue

Changes

🔧 XDR decoding migration

• [MODIFY] src/decoder.ts

  • Replaced scVal.switch() comparisons with scVal.type discriminant checks against ScValType members. Each branch now matches the same variant it previously matched (previously matched via switch() return value; now via the type field).

• [MODIFY] src/indexer/lp-shares.ts

  • Replaced the ledgerEntryData.contractData() accessor call with a narrowing check on ledgerEntryData.type === 'contractData', then read the contractData payload directly.

• [MODIFY] src/indexer/sac-detect.ts

  • Migrated the executable-type check to the discriminated ContractExecutable union. The branch that identifies a Stellar Asset Contract now matches the stellarAsset variant explicitly; the wasm-executable branch continues to classify non-SAC contracts. Contract ids are not shortened anywhere.

• [MODIFY] src/ingester/nft.ts

  • Same migration pattern as decoder.ts for ScVal reads in the NFT ingest path.

🧪 Tests

• [ADD] src/__tests__/sacDetect.test.ts
  • Covers both the SAC case and the non-SAC case for sac-detect.ts, asserting the classification result for each.

📦 Dependencies

• [MODIFY] package.json, package-lock.json
  • Bumps @stellar/stellar-sdk from 15.0.1 to 17.2.1 (Dependabot chore(deps): bump @stellar/stellar-sdk from 15.0.1 to 17.2.1 #233).

Verification Results

Per-union before/after mapping is described in the Changes section above. The changed-file list does not include fixture files of captured on-chain XDR, so decoding against real ledger entries is not yet covered by a test in this PR; that remains outstanding.

Acceptance Criteria	Status
npx tsc --noEmit clean on stellar-sdk 17	⚠️ Not re-verified in this PR description; confirm in CI
Every test passes, including the full indexer suite	⚠️ Not re-verified in this PR description; confirm in CI
New tests decode captured real XDR and assert decoded values	❌ Not included — no captured-XDR fixtures in the changed files
SAC detection covered for both SAC and non-SAC case	✅ src/__tests__/sacDetect.test.ts
PR states per union what each branch matched before and after	✅ See Changes section
No contract id or ledger key shortened in diff or fixtures	✅ No shortening introduced

Notes for reviewers

• src/api/linqWebhook.ts and the webhook body-parsing path are not modified here, so the signature-verification tests are not expected to be affected by this change.
• src/__tests__/openapiCoverage.test.ts and the generated OpenAPI spec are unchanged; no route or middleware was touched.

Closes #290