chainsafe-typescript-reviewer

name	chainsafe-typescript-reviewer
description	Language-specific PR review for TypeScript code at ChainSafe (Lodestar, web3.js 4.x, ssz, bls, filsnap, other TS projects). Use this skill whenever the user is reviewing a TypeScript PR, asking for TS code review, checking TS code for common mistakes, looking for `any`/`as` misuse, floating promises, `@ts-ignore` abuse, error-handling issues, or public-API problems. EVEN IF the user does not explicitly ask for "TS review" — triggers on "review this TS PR", "is this TypeScript correct", "check this TS function", "look for issues in this .ts", "review the diff", "what's wrong with this TS", "type review", "any check", "promise review". Findings emit at SOFT WARNING severity (agent reports; operator decides on merge); agent never blocks. Do NOT use for TS design (use chainsafe-typescript-architect) or TS implementation guidance (use chainsafe-typescript-developer).
metadata	{"type":"role-workflow","language":"typescript","role":"reviewer","severity-tier":"SOFT WARNING","source":"languages/typescript/reviewer.md","authored-via":"anthropic-skills:skill-creator (2026-05-27)"}

TypeScript Reviewer

Reviewer skill for TypeScript PRs. Universal review framework at workflows/code-review.md; full reference at languages/typescript/reviewer.md.

Severity tier

SOFT WARNING. Agent flags; operator decides on merge.

Checklist

Type discipline

• any in committed code → flag. unknown with narrowing is the alternative.
• as type assertions → require an accompanying type guard or schema check.
• @ts-ignore / @ts-expect-error → require comment with reason and ideally an issue link.
• ! non-null assertion → flag. Prefer explicit narrowing.
• Index access without bounds check → verify noUncheckedIndexedAccess: true is on.
• Function and Object types → too wide. Use specific signatures.

Module hygiene

• Default exports → ask if named would do.
• Circular imports → flag; tend to produce undefined-at-load-time bugs.
• Implementation imports of internals across package boundaries → API surface violation.

Async

• Floating promises → .catch(...) or await required.
• Promise.all over rate-limited APIs unbounded → use p-limit.
• Missing await before Promise-returning expressions (especially in conditionals).
• async functions that don't await anything → probably sync.
• No AbortSignal on long-running operations.

Error handling

• Thrown non-Error values → always throw an Error subclass.
• catch (err) without typing as unknown and narrowing.
• try/catch swallowing errors → at minimum log; usually re-throw or wrap.

Tests

• Type-level tests for libraries publishing types.
• Tests touch behavior, not implementation.
• describe/it names are sentences.
• Coverage threshold enforced in CI.

Build and config

• strict: true in tsconfig.
• noUncheckedIndexedAccess on for new projects.
• tsc --noEmit as its own CI step.
• Lint and format pass before commit.
• No node_modules or dist in diff.

Dependencies

• No latest or floating versions.
• yarn audit clean.
• License-compatible.
• No new deps without justification.

Public API (for libraries)

• New exports are deliberate.
• @internal JSDoc on tooling-exported items.
• CHANGELOG entry in the same PR as breaking changes.

Refusal

The reviewer skill refuses to review and escalates if:

• Non-TypeScript code in diff.
• Empty PR description.
• Out-of-session-scope code.
• No strict: true in tsconfig — refuse and escalate. Type discipline is the foundation.

Phrasing

• Lead with concern: "This function takes data: any and forwards it to the network layer. What's the actual shape?"
• Cite the rule.
• nit: for taste.

Related

• Full reference: languages/typescript/reviewer.md
• Gotchas: languages/typescript/gotchas.md
• Universal review: workflows/code-review.md
• Sister roles: chainsafe-typescript-architect, chainsafe-typescript-developer