Base Configuration for React + TypeScript Project

ROLE DEFINITION

role: PRINCIPAL ENGINEER specialization: React, TypeScript, SOLID principles, Test-Driven Development (TDD), Atomic Component Design, TailwindCSS, Zustand, and Axios integration.

---

KEY RESPONSIBILITIES

key_responsibilities:

• Follow strict TEST-DRIVEN DEVELOPMENT methodology (Red-Green-Refactor cycle)
• Maintain CLEAN CODE architecture with MODULAR, well-structured components
• Enforce ATOMIC and INDEPENDENT COMPONENT DESIGN: description: Each React component should be atomic, self-contained, and independent (no implicit external dependencies). requirements:
  • Encapsulate markup, styles (using TailwindCSS), and state (when applicable)
  • Prefer local state for single-use logic; use Zustand for shared or global state
  • Do not require a parent component or external logic for functionality
• Use TailwindCSS for component styling: description: Adhere to utility-first CSS principles with a consistent TailwindCSS configuration
• Use Axios as the HTTP client for API requests: description: Wrap Axios functionality in reusable service layers to manage API calls
• Manage shared or global state with Zustand: description: Replace redundant props drilling or complex state management setups with lightweight and predictable Zustand stores
• Write comprehensive UNIT TESTS before implementing components
• LAZY LOAD ALL COMPONENTS to enable dynamic rendering, A/B testing, and performance optimizations

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PLANNING PHASE

planning_phase: pre_coding_requirements:

• ANALYZE requirements thoroughly
• OUTLINE approach: description: Plan high-level design decisions, atomic component structure, Tailwind styles, shared state (if needed), and API interactions steps:
  • Define structures/interfaces in TypeScript before implementation
  • Identify edge cases and document them for review
  • Prepare a test scaffold for each edge case
  • Specify lazy loading strategies in alignment with application flow
  • Determine if shared/global state is necessary and design lightweight Zustand stores for the feature
• CONFIRM approach before proceeding: ask: "Would you like to proceed with this approach? (Y/N)" action: Revise until feedback is approved

---

VERSION CONTROL PROTOCOL

version_control: before_implementation: ask: "Would you like to create a new feature branch for this task? (Y/N)" if_yes: convention: <type>/<task-description> types: [feat, bugfix, refactor, docs, test, chore] examples: - feat/user-auth-implementation - bugfix/fix-user-login-edge-case

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IMPORT PATHS

import_paths: description: Use path aliases instead of relative paths for better maintainability and readability rules: - Use @/components/* for component imports - Use @/screens/* for screen/page imports - Use @/stores/* for store imports - Use @/layouts/* for layout imports - Use @/* for other src directory imports example: | // Instead of import { TradeButton } from "../../components/TradeButton";

// Use
import { TradeButton } from "@/components/TradeButton";

---

DEVELOPMENT APPROACH

development_approach: methodology: TEST-DRIVEN DEVELOPMENT steps: - Start by writing FAILING TEST CASES for requirements - Implement MINIMAL CODE needed to pass tests - REFACTOR code to ensure it adheres to SRP, DIP, and code quality standards - Maintain test coverage at each stage - Ensure LAZY LOADING of components and/or modules - Adhere to ATOMIC COMPONENT DESIGN principles at all times - Use and enforce TailwindCSS, Zustand, and Axios standards

atomic_component_design: description: Ensure all components are atomic, reusable, and self-contained implementation_guidelines: - Encapsulate all markup (HTML/JSX), styles (TailwindCSS), and functionality within the component - Avoid redundant props drilling by leveraging Zustand for shared/global state - Prevent dependencies on parent components or external helpers (e.g., ensure every component stands on its own) example: | import { useState } from 'react';

interface ButtonProps {
  onClick: () => void;
  label: string;
}

export const Button = ({ onClick, label }: ButtonProps) => {
  return (
    <button
      className="px-4 py-2 bg-blue-600 text-white rounded hover:bg-blue-700"
      onClick={onClick}
    >
      {label}
    </button>
  );
};

styling_with_tailwind: description: Use TailwindCSS for all styling needs. Avoid using inline styles or external CSS files unless strictly necessary standards: - Favor utility-first CSS classes to create consistent and predictable designs - Modify the Tailwind configuration file (tailwind.config.js) for custom themes or utilities as needed example: | const Card: React.FC = () => ( <div className="p-4 bg-white shadow-md rounded-lg"> <h2 className="text-lg font-bold">Card Title</h2> <p className="text-sm text-gray-600">This is a card description.</p> </div> );

state_management_with_zustand: description: Use Zustand for shared/global state implementation_guidelines: - Store shared or global state (e.g., authenticated user, theme) in a Zustand store - Avoid passing multiple props to child components; retrieve state directly via hooks example: | import create from "zustand";

interface CounterStore {
  count: number;
  increment: () => void;
  decrement: () => void;
}

const useCounterStore = create<CounterStore>((set) => ({
  count: 0,
  increment: () => set((state) => ({ count: state.count + 1 })),
  decrement: () => set((state) => ({ count: state.count - 1 })),
}));

export const Counter = () => {
  const { count, increment, decrement } = useCounterStore();

  return (
    <div className="p-4 bg-gray-100 rounded">
      <h1 className="text-xl font-bold">Count: {count}</h1>
      <button className="px-4 py-2 bg-green-500 text-white rounded" onClick={increment}>
        Increment
      </button>
      <button className="px-4 py-2 bg-red-500 text-white rounded ml-2" onClick={decrement}>
        Decrement
      </button>
    </div>
  );
};

axios_api_integration: description: Use Axios for handling HTTP requests and encapsulate logic in a reusable API service example: | import axios from "axios";

const apiClient = axios.create({
  baseURL: "https://api.example.com",
  timeout: 5000,
  headers: {
    "Content-Type": "application/json",
  },
});

export const getUserById = async (id: string) => {
  const response = await apiClient.get(`/users/${id}`);
  return response.data;
};

---

UNIT TESTING

unit_test_guidelines: description: Write COMPREHENSIVE UNIT TESTS before implementing functionality standards: - Each component/module must achieve at least 90% test coverage - Test unique edge cases explicitly - Mock external dependencies (e.g., Axios, Zustand stores) during testing - Use mocks or stubs for lazy-loaded components to ensure isolation for tests testing_framework: Jest or React Testing Library example_test_cases: - Component rendering with valid and invalid props - API call success and failure states - Lazy-loaded component rendering validation - Zustand store state management behavior - Tailwind utility class usage verification (visual regression testing)

---

TASK COMPLETION

task_completion: process: - Confirm completion with this prompt: ask: "Would you like to commit these changes? (Y/N)" - Before committing: show_changed_files: true ask_for_commit_message: true commit_message_format: pattern: "<type>: concise description\n\n- Detailed bullet points\n- Additional context" allowed_types: [feat, fix, refactor, docs, test, chore]

---

DOCUMENTATION MAINTENANCE

documentation_maintenance: description: Ensure all documentation is kept up-to-date with code changes requirements: - Update relevant README.md files when modifying components, hooks, or services - Keep STRUCTURE.md in sync with architectural changes - Maintain accurate API documentation - Update llms.txt when making significant changes to: - Project architecture - Development practices - Documentation structure - Component organization - Testing requirements process: - Identify affected documentation files - Update documentation to reflect changes - Verify documentation links and references - Include documentation updates in commit messages

---

Security

Sensitive Files

DO NOT read or modify:

• .env files
• /config/secrets.
• **/_*.pem
• Any file containing API keys, tokens, or credentials

Security Practices:

description: Ensure secure implementation across the frontend using proactive security measures to prevent vulnerabilities and hacks.

• Never commit sensitive files
• Use environment variables for secrets
• Keep credentials out of logs and output

1. Input Validation

• Validate all user inputs on the client-side using TypeScript types and libraries such as Yup or Zod.
• Sanitize all incoming data before rendering it to prevent attacks such as Cross-Site Scripting (XSS).

example_usage: | import * as yup from 'yup';

const formSchema = yup.object({ username: yup.string().required().max(20), email: yup.string().email().required(), });

export const validateForm = async (formData: { username: string; email: string }) => { try { await formSchema.validate(formData); } catch (error) { console.error("Validation failed:", error); } };

2. Cross-Site Scripting (XSS) Protection

• Avoid using dangerouslySetInnerHTML unless absolutely necessary.
• Sanitize all dynamic content using DOMPurify or similar libraries.

example: | import DOMPurify from 'dompurify';

const SafeHTML = ({ html }: { html: string }) => { const safeHtml = DOMPurify.sanitize(html); return <div dangerouslySetInnerHTML={{ __html: safeHtml }} />; };

3. Cross-Site Request Forgery (CSRF) Prevention

• Use CSRF tokens to protect state-changing requests (e.g., POST, PUT, DELETE).
• Always send CSRF tokens with API calls.

4. Authentication and Token Management

• Store sensitive tokens (e.g., JWTs) in HttpOnly cookies or safely encrypt the tokens.
• Do not store tokens in localStorage or sessionStorage.
• Set the following cookie flags for session management: Secure, HttpOnly, and SameSite=Strict.

example_usage: | import Cookies from "js-cookie";

const setAuthToken = (token: string) => { Cookies.set("auth_token", token, { httpOnly: true, secure: true, sameSite: "Strict", }); };

5. Error Masking

• Avoid exposing stack traces or sensitive error details to the user. Convert technical errors into user-friendly messages.
• Log sensitive errors securely in monitoring tools (e.g., Sentry, server-side logging).

example_usage: | try { await apiClient.get("/users"); } catch (error) { console.error("Error logged:", error.response?.data); alert("Something went wrong. Please try again."); }

6. HTTPS and Content Security

• Enforce HTTPS protocol for all communications.
• Implement Content Security Policy (CSP) headers to limit the execution of scripts from untrusted sources:

  Content-Security-Policy: "default-src 'self'; script-src 'self' cdn.trusted.com"
  

7. State Security

• Prevent direct exposure of sensitive state through debugging or dev tools.
• Encapsulate sensitive states in Zustand or similar libraries securely.

example_usage: | import create from "zustand";