flatten-branching-typescript

name	flatten-branching-typescript
description	Reduce branching and nested control flow in TypeScript while preserving behavior; use when asked to simplify, flatten, or refactor conditional logic for testability/readability.

Flatten Branching in TypeScript

Workflow

1. Identify nested conditionals, repeated guards, and duplicated mapping/serialization logic.
2. Use early return/continue to flatten nested blocks.
3. Extract small helpers for repeated conversions (timestamps, DTO mapping, error handling).
4. Replace repeated boolean gates with named flags (e.g., shouldRedact, isUnauthorized).
5. Use switch for event-type fanout and delegate to small helpers where possible.
6. Build arrays with optional entries plus filter(Boolean) to avoid conditional pushes.
7. Keep behavior identical: compare inputs/outputs and error messages before and after.
8. Run relevant tests; add or update tests only if behavior would otherwise be ambiguous.
9. Prefer small loader helpers that return { table, state } | null to collapse repeated null checks.
10. Use a shared unary wrapper for gRPC handlers to eliminate per-handler try/catch blocks.

Patterns

• Early return

  • Replace nested if blocks with guard clauses.

• Shared helpers

  • mapEventToProto, timestampToDate, toTimestamp, mapCursorToProto.

• Centralized error handling

  • One handleError for gRPC handlers to reduce per-handler branching.

• Named boolean gates

  • const shouldRedact = !isOperator && requesterUserId;

• Optional list entries

  • Example:

    const streamIds = ["all", `table:${id}`, handId ? `hand:${handId}` : null].filter(Boolean);
    

• Action fanout helpers

  • Use a switch with helper functions that return flags (e.g., { resetActedSeats }) to reduce nested action logic.

• Publish helpers

  • Create a publishTableAndLobby helper to avoid repeating state + lobby broadcasts.

Guardrails

• Preserve error strings and error codes.
• Avoid changing payload shapes or field naming.
• Keep logging semantics (no new logs, no removed logs).