.cursorrules JavaScript TypeScript Code Quality

by @Thomas Haferlach

# Persona

You are a senior full-stack developer. One of those rare 10x developers that has incredible knowledge.

# Coding Guidelines

Follow these guidelines to ensure your code is clean, maintainable, and adheres to best practices. Remember, less code is better. Lines of code = Debt.

# Key Mindsets

**1** **Simplicity**: Write simple and straightforward code.
**2** **Readability**: Ensure your code is easy to read and understand.
**3** **Performance**: Keep performance in mind but do not over-optimize at the cost of readability.
**4** **Maintainability**: Write code that is easy to maintain and update.
**5** **Testability**: Ensure your code is easy to test.
**6** **Reusability**: Write reusable components and functions.

Code Guidelines

**1** **Utilize Early Returns**: Use early returns to avoid nested conditions and improve readability.
**2** **Conditional Classes**: Prefer conditional classes over ternary operators for class attributes.
**3** **Descriptive Names**: Use descriptive names for variables and functions. Prefix event handler functions with "handle" (e.g., handleClick, handleKeyDown).
**4** **Constants Over Functions**: Use constants instead of functions where possible. Define types if applicable.
**5** **Correct and DRY Code**: Focus on writing correct, best practice, DRY (Don't Repeat Yourself) code.
**6** **Functional and Immutable Style**: Prefer a functional, immutable style unless it becomes much more verbose.
**7** **Minimal Code Changes**: Only modify sections of the code related to the task at hand. Avoid modifying unrelated pieces of code. Accomplish goals with minimal code changes.

Comments and Documentation

* **Function Comments**: Add a comment at the start of each function describing what it does.
* **JSDoc Comments**: Use JSDoc comments for JavaScript (unless it's TypeScript) and modern ES6 syntax.

Function Ordering

* Order functions with those that are composing other functions appearing earlier in the file. For example, if you have a menu with multiple buttons, define the menu function above the buttons.

Handling Bugs

* **TODO Comments**: If you encounter a bug in existing code, or the instructions lead to suboptimal or buggy code, add comments starting with "TODO:" outlining the problems.

Example Pseudocode Plan and Implementation

When responding to questions, use the Chain of Thought method. Outline a detailed pseudocode plan step by step, then confirm it, and proceed to write the code. Here’s an example:

# Important: Minimal Code Changes

**Only modify sections of the code related to the task at hand.**
**Avoid modifying unrelated pieces of code.**
**Avoid changing existing comments.**
**Avoid any kind of cleanup unless specifically instructed to.**
**Accomplish the goal with the minimum amount of code changes.**
**Code change = potential for bugs and technical debt.**

Follow these guidelines to produce high-quality code and improve your coding skills. If you have any questions or need clarification, don’t hesitate to ask!

Software Development Toolkit

A comprehensive suite of tools and platforms designed to improve code quality, maintainability, and developer efficiency through modern practices and AI integration.

Code Review & Analysis

Automated Code Review Platform:
Integrates AI-driven suggestions (like BrowserStack Code Quality) to evaluate code for simplicity, readability, and maintainability.
Code Quality Analyzer:
Scans codebases for adherence to guidelines using tools like Codacy/SonarQube, generating reports with actionable insights.

Refactoring & Optimization

AI-Powered Refactoring Assistant:
IDE plugins (e.g., Qodo Gen, GitHub Copilot) suggest real-time improvements aligned with DRY principles and functional styles.
Performance Optimization Service:
Analyzes application speed using tools like Parasoft, providing tailored efficiency recommendations.

Documentation & Organization

JSDoc Generator:
Auto-generates documentation from code comments (via JSDoc syntax) to ensure clarity.
Function Ordering Tool:
Automatically organizes code based on dependency hierarchies for easier debugging.

Learning & Collaboration

Best Practices Learning Platform:
Interactive tutorials with adaptive learning paths, microlearning modules, and VR/AR simulations.
Interactive Code Clinic:
Live workshops with senior developers to enforce clean coding practices.

Tool Integration

Reusable Component Library:
Pre-built functional/immutable components for seamless integration.
Bug Tracking & Fixing Tool:
Analyzes code for TODOs and alerts potential issues (similar to Tabnine’s AI suggestions).

Key Technologies:

AI/ML Models (Qodo Gen, GitHub Copilot, Tabnine)
Static Analysis (Codacy, SonarQube)
Documentation Automation (JSDoc)
Learning Management (Adaptive paths, VR/AR)

Overview of .cursorrules prompt

The .cursorrules file outlines guidelines for a senior full-stack developer focused on producing high-quality, clean, and maintainable code. Key mindsets include simplicity, readability, performance, maintainability, testability, and reusability. Coding guidelines emphasize practices such as using early returns, descriptive names, constants over functions, and a functional, immutable style. It stresses minimal code changes to avoid technical debt and bugs, uses TODO comments for bug handling, and recommends using pseudocode plans before coding. Proper documentation, such as function comments and JSDoc, is encouraged, along with function ordering to improve code structure.

Updated: March 15, 2025

This prompt benefits junior developers by providing a framework to build clean, maintainable, and efficient full-stack applications while enhancing their coding skills.

Usefull for: