Code Review Checklist Typescript

Standard Operating Procedure: Enterprise TypeScript Code Review Protocol

1. Document Control Block

• Document ID: SOP-TR-ENG-TS-042
• Effective Date: October 24, 2023
• Version: 2.4.0
• Review Cadence: Semi-Annually
• Target Audience: Software Engineers, Senior Technical Leads, Principal Architects, Quality Assurance Engineers at Template Registry

2. Executive Summary & Scope

This Standard Operating Procedure establishes the mandatory institutional protocols for conducting static analysis, type verification, and architectural peer reviews of TypeScript artifacts within Template Registry production systems. Compliance with this SOP is mandatory for all pull requests (PRs) targeting staging and production branches. The operational boundaries encompass all client-side, server-side, and shared library TypeScript codebases. The objective is to maintain strict type safety, eliminate runtime exceptions attributable to type coercion, optimize compilation performance, and enforce ISO/IEC software engineering standards.

3. Prerequisites & Tool Requirements

• Software Access: GitHub Enterprise repository access, SonarQube Enterprise instance, Datadog APM dashboard.
• Local Tooling Requirements:
  • Node.js LTS v18.x or v20.x
  • TypeScript Compiler (tsc) v5.2+
  • ESLint v8.x with @typescript-eslint/parser and @typescript-eslint/eslint-plugin
  • Prettier code formatter configured to enterprise specifications
• Certifications & Training: Internal Template Registry Secure Coding Certification (Level 2 or higher).

4. Roles & Responsibilities (RACI Matrix Table)

5. Step-by-Step Operational Procedure

Phase 1: Automated Gate Verification (Pre-Review)

• Verify that all automated Continuous Integration (CI) checks (GitHub Actions) have completed successfully.
• Confirm zero TypeScript compilation errors (tsc --noEmit exits with code 0).
• Confirm SonarQube quality gate passes with 0 Security Hotspots and maintainability rating of 'A'.
• Verify unit test coverage meets or exceeds the 85% threshold across all modified files.

Phase 2: Architectural & Type Design Verification

• Verify that the use of the any type is strictly absent; validate that unknown types are properly narrowed using type guards.
• Inspect interface and type alias definitions to ensure structural alignment with domain models and zero redundant duplication.
• Ensure proper utilization of utility types (Partial, Required, Readonly, Record, Omit, Pick) rather than manual type recreation.
• Validate that nullability is explicit; ensure strict null checks are respected without unauthorized non-null assertions (!).

Phase 3: Code Quality, Safety, and Performance Audit

• Check for circular dependencies using Madge or equivalent architectural analysis tools.
• Validate async/await patterns; ensure all promises are explicitly handled, caught, or returned to prevent unhandled rejection leaks.
• Inspect closure scopes and memory allocation hot paths to prevent potential memory leaks in long-running Node.js processes.
• Verify that external library inputs are runtime-validated using schema validation frameworks (e.g., Zod or io-ts) at system boundaries.

Phase 4: Maintainability and Documentation Sign-Off

• Ensure public APIs, exported interfaces, and complex algorithmic blocks are documented using valid TSDoc syntax.
• Confirm adherence to enterprise naming conventions (PascalCase for types/interfaces, camelCase for variables/functions, UPPER_SNAKE_CASE for constants).
• Verify that dead code, commented-out logic, and console debugging statements have been completely purged.

6. Quality Assurance & Verification Criteria

• Tolerance Thresholds: Zero tolerance for compiler suppressions (// @ts-ignore or // @ts-nocheck) in production code paths without an attached Jira ticket justification and Lead Architect sign-off.
• Acceptance Benchmarks: Pull requests must receive a minimum of two explicit approvals from designated Reviewers, including one from the respective Module Owner, prior to merge execution.
• Audit Trail: All review comments, security flags, and exception waivers must be immutably logged within the GitHub Pull Request audit trail.

7. Practical Troubleshooting Scenarios

Scenario A: Unauthorized Use of any Type in Legacy Integration

• Symptom: PR fails automated review due to any usage injected to bypass rapid typing of a legacy third-party payload.
• Immediate Corrective Action Protocol:
  1. Reject the PR review immediately with reference to SOP Section 5, Phase 2.
  2. Instruct the Author to define an explicit interface or utilize an unknown type coupled with a custom type guard function.
  3. If third-party types are entirely missing, mandate the creation of a local declaration file (.d.ts) with accurate ambient module declarations.

Scenario B: Circular Dependency Detected in Core Module

• Symptom: Madge CI check flags a circular dependency loop between auth.service.ts and user.repository.ts.
• Immediate Corrective Action Protocol:
  1. Block merge execution.
  2. Require the Author to refactor shared logic into a decoupled utility module or implement Dependency Inversion Principle (DIP) via TypeScript interfaces.
  3. Re-run local circular dependency analysis before re-submitting for review.

Authorized by Julian Vance, Chief Operations Architect, Template Registry.