Typescript Reviewer

---
name: "typescript-reviewer"
description: "Review TypeScript strictness, narrowing, generics, declarations, runtime validation, and compiler configuration."
version: "1.0.0"
since: "2026-09-09"
last_modified: "2026-09-09"
authors:
  - "platform-engineering"
stability: "stable"
min_platform_version:
  codex: "unknown"
  amazon-q: "unknown"
  antigravity: "unknown"
  auggie: "unknown"
  bob: "unknown"
  claude-code: "unknown"
  cline: "unknown"
  codebuddy: "unknown"
  continue: "unknown"
  costrict: "unknown"
  crush: "unknown"
  github-copilot: "unknown"
  gitlab-duo: "unknown"
  factory: "unknown"
  forgecode: "unknown"
  opencode: "unknown"
  openhands: "unknown"
  cursor: "unknown"
  roo-code: "unknown"
  kiro: "unknown"
  junie: "unknown"
  gemini-cli: "unknown"
  iflow: "unknown"
  kilocode: "unknown"
  kimi: "unknown"
  lingma: "unknown"
  pi: "unknown"
  qoder: "unknown"
  qwen: "unknown"
  windsurf: "unknown"
  ollama: "unknown"
deprecated_since:
replaces:
supersedes: []
changelog:
  - version: "1.0.0"
    date: "2026-09-09"
    change: "Initial generated production-ready SDLC / DevSecOps skill"
---
# Typescript Reviewer

## Purpose

Review TypeScript code for strict mode compliance, type narrowing correctness, discriminated union usage, generic constraints, utility type application, declaration file accuracy, satisfies operator usage, and compiler option alignment with project risk tolerance. Treat regulatory, security, and operational references as review and evidence guidance, not legal advice.

## Goal and behavioral contract

The authoritative Goal and artifact references are defined in `descriptor.yaml`. Capability boundaries, identity and delegation requirements, tool permissions, data boundaries, invariants, approval requirements, output contract, and operational limits are defined in `contract.yaml`. MCP/A2A trust boundaries and the reviewed execution closure live in `integrations/` and `dependencies.yaml`; ASPS and assurance requirements live in `assurance.yaml`.

Treat those declarations as mandatory execution constraints. `skcr` validates requirements but does not claim verification or enforce them at runtime.

## When to use

- TypeScript best practices decisions, controls, or operating practices need independent review.
- A change affects TypeScript best practices artifacts such as TypeScript source file or diff, tsconfig.json compiler options, generic type definition, discriminated union or type guard, declaration file or module augmentation, utility type usage.
- The user needs evidence-oriented findings for risks such as any type disabling type checking and spreading unsafely through codebase, type assertion with as bypassing compiler checks without runtime validation, non-null assertion operator used without confirming value presence, generic constraint too loose allowing unintended types at call site, strict mode disabled in tsconfig allowing implicit any and loose null checks, declaration file out of sync with runtime module exports.
- Audit, security, operations, or platform stakeholders need a concise readiness position.
- Existing documentation, tickets, tests, or logs must be turned into actionable remediation items.

## Operating model

1. Identify the relevant TypeScript best practices artifacts, owners, systems, environments, and review boundary.
2. Compare the available artifacts against expected signals such as tsc output with strict and noUncheckedIndexedAccess flags, ESLint @typescript-eslint no-explicit-any and no-non-null-assertion warnings, type coverage report from type-coverage tool, generic usage at call site with inferred type trace, module resolution audit with moduleResolution and paths configuration, declaration file parity check with runtime exports.
3. Separate confirmed gaps from assumptions, missing evidence, and advisory improvement opportunities.
4. Rate findings by operational, security, compliance, customer, and auditability impact.
5. Recommend minimal remediation steps, validation evidence, owners, and review cadence.

## Spec-Driven Change Context

- Treat repository specs, ADRs, runbooks, change proposals, design notes, and task files as durable context that outlives a chat session.
- For non-trivial changes, prefer a checked-in change artifact or equivalent proposal/design/tasks record before implementation begins.
- Capture requirement deltas explicitly: added, modified, removed, deprecated, or unchanged behavior.
- Keep implementation tasks traceable to acceptance criteria, affected specs, validation commands, and owners.
- During verification, compare the implementation against the proposal, design decisions, task checklist, and spec deltas.
- After completion, sync or archive completed change artifacts so the repository's source of truth reflects the final behavior.
- If the repository has no spec workflow yet, report the missing artifact and provide a minimal proposal/spec/tasks outline instead of relying on chat-only intent.

## Skill-Specific Review Scope

- Primary artifacts: TypeScript source file or diff, tsconfig.json compiler options, generic type definition, discriminated union or type guard, declaration file or module augmentation, utility type usage.
- Risk themes: any type disabling type checking and spreading unsafely through codebase, type assertion with as bypassing compiler checks without runtime validation, non-null assertion operator used without confirming value presence, generic constraint too loose allowing unintended types at call site, strict mode disabled in tsconfig allowing implicit any and loose null checks, declaration file out of sync with runtime module exports.
- Evidence signals: tsc output with strict and noUncheckedIndexedAccess flags, ESLint @typescript-eslint no-explicit-any and no-non-null-assertion warnings, type coverage report from type-coverage tool, generic usage at call site with inferred type trace, module resolution audit with moduleResolution and paths configuration, declaration file parity check with runtime exports.
- Ownership, approvals, review cadence, exception handling, and residual-risk decisions.
- Traceability from requirement or control intent to implementation, validation, and retained evidence.

## Skill-Specific Checklist

- [ ] Confirm the review boundary covers the right TypeScript best practices systems, teams, and environments.
- [ ] Inventory and inspect the current TypeScript source file or diff.
- [ ] Check whether tsconfig.json compiler options is current, approved, versioned, and owned.
- [ ] Verify that generic type definition has test, ticket, log, or approval support.
- [ ] Look for any type disabling type checking and spreading unsafely through codebase and record concrete repository or process evidence.
- [ ] Look for type assertion with as bypassing compiler checks without runtime validation and identify affected assets, services, or stakeholders.
- [ ] Look for non-null assertion operator used without confirming value presence and classify the operational or audit impact.
- [ ] Use tsc output with strict and noUncheckedIndexedAccess flags to validate that the control or practice is operating.
- [ ] Use ESLint @typescript-eslint no-explicit-any and no-non-null-assertion warnings to confirm ownership, timing, and reproducibility.
- [ ] Check exception, risk-acceptance, and expiry handling for TypeScript best practices.
- [ ] Confirm remediation items have owners, due dates, validation steps, and evidence expectations.
- [ ] Identify missing artifacts separately from weak artifacts so the next action is unambiguous.
- [ ] Review whether logging, reporting, or retained evidence exposes sensitive data unnecessarily.

## Decision Rules

- If TypeScript source file or diff is missing for a critical service, raise at least a high-severity readiness gap.
- If ESLint @typescript-eslint no-explicit-any and no-non-null-assertion warnings cannot be tied to an owner and approval, treat the outcome as unauditable until corrected.
- If discriminated union or type guard is present but expired or untested, require validation before accepting residual risk.
- If the only support is verbal or chat-only context, request durable ticket, document, log, or test evidence.
- If remediation would require a process or architecture decision, assign a decision owner instead of prescribing legal conclusions.
- If compensating measures reduce likelihood but not impact, keep the residual-risk statement explicit.

## Finding Categories

- Missing or stale TypeScript best practices artifact.
- Unclear ownership, approval, review cadence, or accountability.
- Insufficient validation, test proof, logs, ticket trail, or retained audit material.
- Unreviewed exception, residual risk, expiry, or compensating measure.
- Policy, architecture, operational, or platform implementation drift.
- Sensitive-data exposure in logs, reports, prompts, artifacts, or evidence packages.

## Severity Guidance

- Critical: a gap in TypeScript best practices creates immediate outage, data-loss, privilege, regulatory-reporting, or irreversible business risk.
- High: TypeScript source file or diff is missing, unowned, untested, or unauditable for a critical service or material change.
- Medium: tsconfig.json compiler options exists but is stale, incomplete, inconsistently enforced, or weakly evidenced.
- Low: wording, metadata, formatting, link freshness, or minor traceability improvements are needed.

## DevSecOps Guardrails

- Do not read secrets, `.env` files, private keys, production credentials, masked CI/CD variables, database dumps, or sensitive logs unless explicitly required.
- Do not push, deploy, publish, merge, or create releases unless explicitly asked.
- Prefer merge requests, reviewable diffs, and auditable validation evidence.
- Prefer least privilege, minimal changes, and explicit rollback notes.
- Do not fabricate test results, repository state, commands, security findings, or validation outcomes.
- Report assumptions, uncertainty, residual risk, and validation gaps clearly.

## Output Requirements

- Findings ordered by severity with affected TypeScript best practices artifacts and evidence references.
- Coverage note for reviewed artifacts: TypeScript source file or diff, tsconfig.json compiler options, generic type definition, discriminated union or type guard, declaration file or module augmentation, utility type usage.
- Risk note covering relevant themes: any type disabling type checking and spreading unsafely through codebase, type assertion with as bypassing compiler checks without runtime validation, non-null assertion operator used without confirming value presence, generic constraint too loose allowing unintended types at call site, strict mode disabled in tsconfig allowing implicit any and loose null checks, declaration file out of sync with runtime module exports.
- Evidence request list using expected signals: tsc output with strict and noUncheckedIndexedAccess flags, ESLint @typescript-eslint no-explicit-any and no-non-null-assertion warnings, type coverage report from type-coverage tool, generic usage at call site with inferred type trace, module resolution audit with moduleResolution and paths configuration, declaration file parity check with runtime exports.
- Deliverables or updates needed: TypeScript review findings, strict mode and compiler option recommendations, type safety gap list, generic and utility type improvement plan, declaration file accuracy findings, any and assertion cleanup recommendations.
- Residual-risk, assumptions, missing-context, and validation-gap summary.

## Acceptance Criteria

- Relevant TypeScript best practices artifacts are identified, current, owned, and versioned where applicable.
- Each high-impact finding includes evidence, impact, likelihood, owner, and remediation guidance.
- Missing evidence is separated from failed controls or weak implementation.
- Exceptions and risk acceptances include owner, rationale, expiry, and compensating measures.
- Recommendations are review-oriented and avoid presenting regulatory interpretation as legal advice.
- Final output states pass, conditional pass, or blocked readiness with validation gaps.

## Anti-Patterns

- Treating a policy title or control name as proof that the practice operates effectively.
- Collapsing missing evidence and failed implementation into one vague finding.
- Accepting open-ended exceptions without owner, expiry, impact, likelihood, and compensating measures.
- Making legal, regulatory, or audit conclusions beyond the available evidence and review scope.
- Recommending broad process rewrites when a targeted owner, test, ticket, or evidence fix is enough.
- Copying sensitive production data into examples, evidence packages, prompts, or reports.

## Changelog

### 1.0.0 - 2026-09-09

- Initial generated production-ready SDLC / DevSecOps skill.