rakesh kumar

Posted on May 28

List out best software coding architecture usung js

Here are some best practices for software coding architecture using JavaScript, along with examples:

Modularization

Best Practice: Break your code into smaller, reusable modules. This makes the code easier to manage and test.

// mathUtils.js
export function add(a, b) {
  return a + b;
}

export function subtract(a, b) {
  return a - b;
}

// main.js
import { add, subtract } from './mathUtils';

console.log(add(5, 3)); // 8
console.log(subtract(5, 3)); // 2

Use of ES6+ Features
Best Practice: Utilize modern JavaScript features like let, const, arrow functions, and template literals for cleaner and more readable code.

Example:

const user = {
  name: 'John Doe',
  age: 30
};

const greet = (user) => `Hello, ${user.name}!`;

console.log(greet(user)); // Hello, John Doe!

Separation of Concerns
Best Practice: Separate business logic, presentation logic, and data access. This makes the codebase easier to maintain and extend.

Example:

// dataService.js
export const fetchData = async (url) => {
  const response = await fetch(url);
  return response.json();
};

// uiService.js
export const renderData = (data) => {
  const container = document.getElementById('data-container');
  container.innerHTML = JSON.stringify(data, null, 2);
};

// app.js
import { fetchData } from './dataService';
import { renderData } from './uiService';

const init = async () => {
  const data = await fetchData('https://api.example.com/data');
  renderData(data);
};

init();

Single Responsibility Principle Best Practice: Each function or module should have a single responsibility or purpose.

Example:

// logger.js
export const logMessage = (message) => {
  console.log(message);
};

// validator.js
export const isEmailValid = (email) => {
  const regex = /\S+@\S+\.\S+/;
  return regex.test(email);
};

// main.js
import { logMessage } from './logger';
import { isEmailValid } from './validator';

const email = 'test@example.com';

if (isEmailValid(email)) {
  logMessage('Email is valid');
} else {
  logMessage('Email is invalid');
}

Consistent Naming Conventions Best Practice: Use clear and consistent naming conventions for variables, functions, and classes.

Example:

// Consistent camelCase for variables and functions
const userName = 'JohnDoe';

function getUserName() {
  return userName;
}

Error Handling Best Practice: Implement proper error handling to make your application more robust.

Example:

// fetchData.js
export const fetchData = async (url) => {
  try {
    const response = await fetch(url);
    if (!response.ok) {
      throw new Error('Network response was not ok');
    }
    return response.json();
  } catch (error) {
    console.error('Fetch error:', error);
    throw error;
  }
};

// main.js
import { fetchData } from './fetchData';

const init = async () => {
  try {
    const data = await fetchData('https://api.example.com/data');
    console.log('Data:', data);
  } catch (error) {
    console.error('Error initializing app:', error);
  }
};

init();

Documentation Best Practice: Document your code to make it easier for others (and yourself) to understand.

Example:

/**
 * Adds two numbers.
 *
 * @param {number} a - The first number.
 * @param {number} b - The second number.
 * @returns {number} The sum of the two numbers.
 */
export function add(a, b) {
  return a + b;
}

8. Testing
Best Practice: Write unit tests to ensure your code works as expected.

Example using Jest:

// mathUtils.js
export function add(a, b) {
  return a + b;
}

// mathUtils.test.js
import { add } from './mathUtils';

test('adds 1 + 2 to equal 3', () => {
  expect(add(1, 2)).toBe(3);
});

9. Avoid Global Variables
Best Practice: Avoid using global variables as they can lead to conflicts and bugs.

Example:

// Avoid this
let globalCounter = 0;

// Instead, use module-scoped variables
let counter = 0;

export const incrementCounter = () => {
  counter++;
  return counter;
};

Use State Management Libraries for Complex Applications Best Practice: For complex applications, use state management libraries like Redux to manage the application state in a predictable way.

Example using Redux:

// actions.js
export const increment = () => ({
  type: 'INCREMENT'
});

// reducer.js
const initialState = {
  count: 0
};

const counterReducer = (state = initialState, action) => {
  switch (action.type) {
    case 'INCREMENT':
      return { count: state.count + 1 };
    default:
      return state;
  }
};

export default counterReducer;

// store.js
import { createStore } from 'redux';
import counterReducer from './reducer';

const store = createStore(counterReducer);

export default store;

// main.js
import store from './store';
import { increment } from './actions';

store.subscribe(() => console.log(store.getState()));

store.dispatch(increment()); // { count: 1 }

By following these best practices, you can write clean, maintainable, and scalable JavaScript code.

State Management with Context API

Best Practice: Use Context API for simple state management across components.

Example:

import React, { createContext, useState, useContext } from 'react';

const ThemeContext = createContext();

export const ThemeProvider = ({ children }) => {
  const [theme, setTheme] = useState('light');

  const toggleTheme = () => {
    setTheme((prevTheme) => (prevTheme === 'light' ? 'dark' : 'light'));
  };

  return (
    <ThemeContext.Provider value={{ theme, toggleTheme }}>
      {children}
    </ThemeContext.Provider>
  );
};

export const useTheme = () => useContext(ThemeContext);

// App.js
import React from 'react';
import { ThemeProvider, useTheme } from './ThemeContext';

const ThemeToggleButton = () => {
  const { theme, toggleTheme } = useTheme();
  return (
    <button onClick={toggleTheme}>
      Toggle to {theme === 'light' ? 'dark' : 'light'} theme
    </button>
  );
};

const App = () => (
  <ThemeProvider>
    <div>
      <h1>Hello, World!</h1>
      <ThemeToggleButton />
    </div>
  </ThemeProvider>
);

export default App;

12. Component Architecture
Best Practice: Organize your components into functional (presentational) and container (stateful) components.

Example:

component architecture

// Presentational Component (Button.js)
import React from 'react';

const Button = ({ label, onClick }) => (
  <button onClick={onClick}>{label}</button>
);

export default Button;

// Container Component (ButtonContainer.js)
import React, { useState } from 'react';
import Button from './Button';

const ButtonContainer = () => {
  const [count, setCount] = useState(0);

  const handleClick = () => {
    setCount(count + 1);
  };

  return (
    <div>
      <Button label={`Clicked ${count} times`} onClick={handleClick} />
    </div>
  );
};

export default ButtonContainer;

// App.js
import React from 'react';
import ButtonContainer from './ButtonContainer';

const App = () => (
  <div>
    <h1>My App</h1>
    <ButtonContainer />
  </div>
);

export default App;

13. Use Hooks for Reusable Logic
Best Practice: Use custom hooks to encapsulate reusable logic.

Example:

// useCounter.js
import { useState } from 'react';

export const useCounter = (initialValue = 0) => {
  const [count, setCount] = useState(initialValue);

  const increment = () => setCount(count + 1);
  const decrement = () => setCount(count - 1);
  const reset = () => setCount(initialValue);

  return { count, increment, decrement, reset };
};

// CounterComponent.js
import React from 'react';
import { useCounter } from './useCounter';

const CounterComponent = () => {
  const { count, increment, decrement, reset } = useCounter(10);

  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={increment}>Increment</button>
      <button onClick={decrement}>Decrement</button>
      <button onClick={reset}>Reset</button>
    </div>
  );
};

export default CounterComponent;

14. Centralized State Management with Redux
Best Practice: Use Redux for managing complex state across the application.

Example:

export const increment = () => ({
  type: 'INCREMENT'
});

export const decrement = () => ({
  type: 'DECREMENT'
});

// reducer.js
const initialState = {
  count: 0
};

const counterReducer = (state = initialState, action) => {
  switch (action.type) {
    case 'INCREMENT':
      return { count: state.count + 1 };
    case 'DECREMENT':
      return { count: state.count - 1 };
    default:
      return state;
  }
};

export default counterReducer;

// store.js
import { createStore } from 'redux';
import counterReducer from './reducer';

const store = createStore(counterReducer);

export default store;

// CounterComponent.js
import React from 'react';
import { useSelector, useDispatch } from 'react-redux';
import { increment, decrement } from './actions';

const CounterComponent = () => {
  const count = useSelector((state) => state.count);
  const dispatch = useDispatch();

  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={() => dispatch(increment())}>Increment</button>
      <button onClick={() => dispatch(decrement())}>Decrement</button>
    </div>
  );
};

export default CounterComponent;

// App.js
import React from 'react';
import { Provider } from 'react-redux';
import store from './store';
import CounterComponent from './CounterComponent';

const App = () => (
  <Provider store={store}>
    <div>
      <h1>My App</h1>
      <CounterComponent />
    </div>
  </Provider>
);

export default App;

Immutable Data Structures Best Practice: Use immutable data structures to avoid unintended side effects.

Example:

// Using Object.assign
const state = { count: 0 };
const newState = Object.assign({}, state, { count: state.count + 1 });

// Using Spread Operator
const state = { count: 0 };
const newState = { ...state, count: state.count + 1 };

// Using Immutable.js
import { Map } from 'immutable';

let state = Map({ count: 0 });
state = state.set('count', state.get('count') + 1);

console.log(state.get('count')); // 1

Component Composition Best Practice: Compose components to create complex UIs from simple building blocks.

Example:

// Button.js
import React from 'react';

const Button = ({ label, onClick }) => (
  <button onClick={onClick}>{label}</button>
);

export default Button;

// Dialog.js
import React from 'react';

const Dialog = ({ title, children }) => (
  <div className="dialog">
    <h2>{title}</h2>
    <div className="dialog-body">
      {children}
    </div>
  </div>
);

export default Dialog;

// App.js
import React from 'react';
import Button from './Button';
import Dialog from './Dialog';

const App = () => (
  <div>
    <Dialog title="My Dialog">
      <p>This is a dialog</p>
      <Button label="Close" onClick={() => alert('Dialog closed')} />
    </Dialog>
  </div>
);

export default App;

Component Prop Types and Default Props Best Practice: Define prop types and default props for your components to improve readability and catch potential bugs.

Example:

import React from 'react';
import PropTypes from 'prop-types';

const Button = ({ label, onClick }) => (
  <button onClick={onClick}>{label}</button>
);

Button.propTypes = {
  label: PropTypes.string.isRequired,
  onClick: PropTypes.func.isRequired
};

Button.defaultProps = {
  label: 'Click me'
};

export default Button;

Responsive Design Best Practice: Make your components responsive to different screen sizes using CSS or responsive design libraries.

Example:

/* styles.css */
.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

.card {
  width: 100%;
  max-width: 300px;
  margin: 10px;
  padding: 20px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

@media (min-width: 600px) {
  .card {
    width: 45%;
  }
}

@media (min-width: 900px) {
  .card {
    width: 30%;
  }
}

import React from 'react';
import './styles.css';

const Card = ({ title, content }) => (
  <div className="card">
    <h2>{title}</h2>
    <p>{content}</p>
  </div>
);

const App = () => (
  <div className="container">
    <Card title="Card 1" content="This is the first card." />
    <Card title="Card 2" content="This is the second card." />
    <Card title="Card 3" content="This is the third card." />
  </div>
);

export default App;

19. Code Splitting
Best Practice: Use code splitting to load parts of the application only when they are needed, improving performance.

Example:

import React, { Suspense, lazy } from 'react';

const LazyComponent = lazy(() => import('./LazyComponent'));

const App = () => (
  <div>
    <h1>My App</h1>
    <Suspense fallback={<div>Loading...</div>}>
 <Suspense fallback={<div>Loading...</div>}>
      <LazyComponent />
    </Suspense>
  </div>
);

export default App;

Error Boundaries
Best Practice: Use error boundaries to catch JavaScript errors anywhere in your component tree and display a fallback UI.

Example:

import React, { Component } from 'react';

class ErrorBoundary extends Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }

  static getDerivedStateFromError(error) {
    // Update state so the next render will show the fallback UI.
    return { hasError: true };
  }

  componentDidCatch(error, errorInfo) {
    // You can also log the error to an error reporting service
    console.log(error, errorInfo);
  }

  render() {
    if (this.state.hasError) {
      // You can render any custom fallback UI
      return <h1>Something went wrong.</h1>;
    }

    return this.props.children;
  }
}

// Usage
import React from 'react';
import ErrorBoundary from './ErrorBoundary';
import MyComponent from './MyComponent';

const App = () => (
  <ErrorBoundary>
    <MyComponent />
  </ErrorBoundary>
);

export default App;

Accessibility Best Practice: Ensure your components are accessible by following ARIA guidelines and using semantic HTML elements.

Example:

import React from 'react';

const AccessibleButton = ({ label, onClick }) => (
  <button onClick={onClick} aria-label={label}>
    {label}
  </button>
);

export default AccessibleButton;

**CSS-in-JS **Best Practice: Use CSS-in-JS libraries like styled-components or Emotion for scoped and maintainable styles.

Example using styled-components:

import React from 'react';
import styled from 'styled-components';

const Button = styled.button`
  background-color: #4CAF50;
  color: white;
  padding: 10px 20px;
  border: none;
  border-radius: 5px;
  cursor: pointer;

  &:hover {
    background-color: #45a049;
  }
`;

const App = () => (
  <div>
    <Button>Click Me</Button>
  </div>
);

export default App;

Use TypeScript for Type Safety Best Practice: Use TypeScript to catch type errors early and improve code quality.

Example:

// Button.tsx
import React from 'react';

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

const Button: React.FC<ButtonProps> = ({ label, onClick }) => (
  <button onClick={onClick}>{label}</button>
);

export default Button;

// App.tsx
import React from 'react';
import Button from './Button';

const App: React.FC = () => (
  <div>
    <h1>My App</h1>
    <Button label="Click Me" onClick={() => alert('Button clicked!')} />
  </div>
);

export default App;

Optimize Performance with useMemo and useCallback Best Practice: Use useMemo and useCallback to optimize performance by memoizing expensive calculations and functions.

Example:

import React, { useState, useMemo, useCallback } from 'react';

const ExpensiveComponent = ({ compute }) => {
  const result = useMemo(() => compute(), [compute]);
  return <div>{result}</div>;
};

const App = () => {
  const [count, setCount] = useState(0);

  const compute = useCallback(() => {
    // Simulate expensive computation
    let result = 0;
    for (let i = 0; i < 1000000000; i++) {
      result += i;
    }
    return result;
  }, []);

  return (
    <div>
      <button onClick={() => setCount(count + 1)}>Increment</button>
      <ExpensiveComponent compute={compute} />
    </div>
  );
};

export default App;

Use Lazy Loading for Routes Best Practice: Use lazy loading for routes to improve initial load time.

Example:

import React, { Suspense, lazy } from 'react';
import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';

const Home = lazy(() => import('./Home'));
const About = lazy(() => import('./About'));

const App = () => (
  <Router>
    <Suspense fallback={<div>Loading...</div>}>
      <Switch>
        <Route exact path="/" component={Home} />
        <Route path="/about" component={About} />
      </Switch>
    </Suspense>
  </Router>
);

export default App;