Backend - Refactor duplicated contract-error normalization between contracts.ts and errors.ts

[1nonlypiece]

Backend - Refactor duplicated contract-error normalization between contracts.ts and errors.ts

Description

src/lib/backend/services/contracts.ts defines a local normalizeContractError that overlaps with normalizeBackendError in src/lib/backend/errors.ts, and the two are mixed inconsistently across functions (some catch blocks use one, others the other). Consolidate into a single normalization path to ensure consistent retryable classification.

Requirements and context

• Must be secure, tested, and documented
• Should be efficient and easy to review
• Centralize chain-error mapping in src/lib/backend/errors.ts
• Replace mixed usage across all functions in contracts.ts
• Preserve the retryable flags for 429/503/504/timeout
• Keep raw RPC details out of client responses

Suggested execution

• Fork the repo and create a branch
• git checkout -b chore/consolidate-contract-error-normalization
• Implement changes
  • Move/merge the normalizer into errors.ts
  • Update all catch blocks in contracts.ts
  • Extend tests in src/lib/backend/errors.test.ts
  • Document the unified mapping in docs/backend-error-codes.md
• Test and commit
  • Run tests, cover edge cases
  • Include test output and notes

Example commit message

refactor: unify contract-error normalization into errors.ts

Guidelines

• Minimum 95 percent test coverage
• Clear documentation
• Timeframe: 96 hours

[Riel101]

@Riel101 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

I can refactor this for you

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Riel101 to this issue.

[drips-wave]

Congratulations, @Riel101! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

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