Utility Functions & Helpers

The SDK includes several utility functions to simplify common operations like phone number formatting, retry logic, text processing, and more.

Phone Number Utilities

formatPhoneNumber()

Formats phone numbers to international format with + prefix.

function formatPhoneNumber(phoneNumber: string): string

Parameters:

phoneNumber - Phone number string to format

Returns:

Formatted phone number with + prefix

Examples:

import { formatPhoneNumber } from 'whatsapp-client-sdk';

// Add missing + prefix
formatPhoneNumber('573001234567');   // '+573001234567'
formatPhoneNumber('1234567890');     // '+1234567890'

// Already formatted numbers remain unchanged
formatPhoneNumber('+573001234567');  // '+573001234567'

validatePhoneNumber()

Validates international phone number format.

import { validatePhoneNumber } from 'whatsapp-client-sdk';

const isValid = validatePhoneNumber('+573001234567'); // true
const isInvalid = validatePhoneNumber('123');         // false

Retry Logic & Error Handling

withRetry()

Executes a function with automatic retry logic and exponential backoff.

async function withRetry<T>(
  fn: () => Promise<T>,
  options: RetryOptions = {}
): Promise<T>

Parameters:

fn - Async function to execute
options - Retry configuration options

Options:

interface RetryOptions {
  maxRetries?: number;     // Default: 3
  initialDelay?: number;   // Default: 1000ms
  backoffFactor?: number;  // Default: 2
  maxDelay?: number;       // Default: 30000ms
}

Examples:

import { withRetry } from 'whatsapp-client-sdk';

// Basic retry with defaults (3 attempts, 1s initial delay)
const result = await withRetry(async () => {
  const response = await fetch('https://api.example.com/data');
  if (!response.ok) throw new Error('API request failed');
  return response.json();
});

// Custom retry configuration
const data = await withRetry(
  () => client.sendText('+573001234567', 'Hello'),
  {
    maxRetries: 5,        // Try up to 5 times
    initialDelay: 2000,   // Start with 2 second delay
    backoffFactor: 1.5,   // Increase delay by 1.5x each retry
    maxDelay: 10000       // Max 10 second delay
  }
);

// Retry pattern: 2s → 3s → 4.5s → 6.75s → 10s

delay()

Promise-based delay function for creating pauses.

async function delay(ms: number): Promise<void>

Parameters:

ms - Milliseconds to delay

Examples:

import { delay } from 'whatsapp-client-sdk';

// Wait 1 second
await delay(1000);

// Rate limiting example
for (const message of messages) {
  await client.sendText(phone, message);
  await delay(2000); // 2 second pause between messages
}

// Exponential backoff
let delayMs = 1000;
for (let attempt = 1; attempt <= 5; attempt++) {
  try {
    await apiCall();
    break; // Success, exit loop
  } catch (error) {
    console.log(`Attempt ${attempt} failed, retrying in ${delayMs}ms`);
    await delay(delayMs);
    delayMs *= 2; // Double the delay
  }
}

Text Processing

truncateText()

Truncates text to specified length with ellipsis.

function truncateText(text: string, maxLength: number): string

Parameters:

text - Text to truncate
maxLength - Maximum character length

Examples:

import { truncateText } from 'whatsapp-client-sdk';

// Basic truncation
truncateText('This is a very long message that exceeds limits', 20);
// Result: 'This is a very lo...'

// WhatsApp limits
const buttonTitle = truncateText(userInput, 20);  // Button titles: 20 chars
const caption = truncateText(description, 1024);  // Captions: 1024 chars
const textMessage = truncateText(content, 4096);  // Text messages: 4096 chars

// No truncation needed
truncateText('Short text', 50); // 'Short text' (unchanged)

sanitizeText()

Removes control characters and normalizes whitespace.

function sanitizeText(text: string): string

Parameters:

text - Text to sanitize

Examples:

import { sanitizeText } from 'whatsapp-client-sdk';

// Remove control characters
sanitizeText('Text with\nline\tbreaks\rand\x00nulls');
// Result: 'Text with line breaks and nulls'

// Normalize whitespace
sanitizeText('  Multiple   spaces   and\n\nlines  ');
// Result: 'Multiple spaces and lines'

// Clean user input
const userMessage = sanitizeText(req.body.message);
await client.sendText(phone, userMessage);

URL Utilities

isValidUrl()

Validates URL format and accessibility.

function isValidUrl(url: string): boolean

Parameters:

url - URL string to validate

Examples:

import { isValidUrl } from 'whatsapp-client-sdk';

// Valid URLs
isValidUrl('https://example.com');           // true
isValidUrl('http://subdomain.example.com');  // true
isValidUrl('https://example.com/path?q=1');  // true

// Invalid URLs
isValidUrl('not-a-url');                     // false
isValidUrl('ftp://example.com');             // false
isValidUrl('https://');                      // false

// Use in message validation
const validateImageMessage = (imageUrl: string) => {
  if (!isValidUrl(imageUrl)) {
    throw new Error('Invalid image URL');
  }
};

Array Utilities

chunk()

Splits arrays into smaller chunks for batch processing.

function chunk<T>(array: T[], size: number): T[][]

Parameters:

array - Array to split
size - Chunk size

Examples:

import { chunk } from 'whatsapp-client-sdk';

// Split contact list for batch processing
const contacts = [/* ... 100 contacts ... */];
const batches = chunk(contacts, 10); // 10 contacts per batch

// Process in batches to avoid rate limits
for (const batch of batches) {
  for (const contact of batch) {
    await client.sendText(contact.phone, 'Hello!');
    await delay(100); // Small delay between messages
  }
  
  console.log(`Processed batch of ${batch.length} contacts`);
  await delay(5000); // Longer delay between batches
}

// Split large arrays
const numbers = Array.from({ length: 100 }, (_, i) => i);
const chunks = chunk(numbers, 25);
// Result: [[0,1,...,24], [25,26,...,49], [50,51,...,74], [75,76,...,99]]

JSON Utilities

safeJsonParse()

Safely parses JSON with fallback values.

function safeJsonParse<T>(json: string, fallback: T): T

Parameters:

json - JSON string to parse
fallback - Fallback value if parsing fails

Examples:

import { safeJsonParse } from 'whatsapp-client-sdk';

// Safe parsing with fallback
const config = safeJsonParse(process.env.CONFIG, {});
const numbers = safeJsonParse(userInput, []);
const settings = safeJsonParse(localStorage.getItem('settings'), { theme: 'light' });

// Parse webhook data safely
const parseWebhookData = (rawData: string) => {
  const data = safeJsonParse(rawData, { entry: [] });
  return data.entry || [];
};

Function Utilities

debounce()

Debounces function execution to prevent rapid repeated calls.

function debounce<T extends (...args: any[]) => any>(
  func: T, 
  wait: number
): (...args: Parameters<T>) => void

Parameters:

func - Function to debounce
wait - Delay in milliseconds

Examples:

import { debounce } from 'whatsapp-client-sdk';

// Debounce message sending to prevent spam
const debouncedSend = debounce(async (phone: string, message: string) => {
  await client.sendText(phone, message);
}, 2000); // 2 second delay

// Multiple rapid calls will only execute once
debouncedSend('+573001234567', 'Hello'); // Will execute
debouncedSend('+573001234567', 'Hello'); // Cancelled
debouncedSend('+573001234567', 'Hello'); // Cancelled
// Only the last call executes after 2 seconds

// Debounce user input processing
const processUserInput = debounce(async (input: string) => {
  const response = await analyzeMessage(input);
  await client.sendText(userPhone, response);
}, 1000);

Usage Examples

Comprehensive Message Processing

import {
  validatePhoneNumber,
  formatPhoneNumber,
  sanitizeText,
  truncateText,
  chunk,
  withRetry,
  delay,
  debounce
} from 'whatsapp-client-sdk';

class MessageProcessor {
  private client: WhatsAppClient;
  
  // Debounced message sender to prevent spam
  private debouncedSend = debounce(this.sendMessage.bind(this), 1000);
  
  constructor(client: WhatsAppClient) {
    this.client = client;
  }
  
  async processBulkMessages(contacts: Contact[], message: string) {
    // Validate and format phone numbers
    const validContacts = contacts
      .filter(contact => validatePhoneNumber(contact.phone))
      .map(contact => ({
        ...contact,
        phone: formatPhoneNumber(contact.phone)
      }));
    
    // Sanitize and truncate message
    const cleanMessage = sanitizeText(message);
    const finalMessage = truncateText(cleanMessage, 4096);
    
    // Process in batches to respect rate limits
    const batches = chunk(validContacts, 10);
    
    for (const batch of batches) {
      await Promise.all(
        batch.map(contact => 
          this.sendMessageWithRetry(contact.phone, finalMessage)
        )
      );
      
      // Delay between batches
      await delay(5000);
    }
  }
  
  private async sendMessageWithRetry(phone: string, message: string) {
    return withRetry(
      () => this.client.sendText(phone, message),
      {
        maxRetries: 3,
        initialDelay: 1000,
        backoffFactor: 2
      }
    );
  }
  
  private async sendMessage(phone: string, message: string) {
    // Implementation here
  }
}

Input Validation and Sanitization

import { 
  validatePhoneNumber, 
  formatPhoneNumber, 
  sanitizeText, 
  isValidUrl,
  truncateText 
} from 'whatsapp-client-sdk';

const processUserInput = async (userPhone: string, userInput: any) => {
  // Validate phone number
  if (!validatePhoneNumber(userPhone)) {
    throw new Error('Invalid phone number format');
  }
  
  const phone = formatPhoneNumber(userPhone);
  
  // Sanitize and validate text message
  if (userInput.message) {
    const cleanMessage = sanitizeText(userInput.message);
    const truncatedMessage = truncateText(cleanMessage, 4096);
    
    await client.sendText(phone, truncatedMessage);
  }
  
  // Validate URLs in media messages
  if (userInput.mediaUrl && !isValidUrl(userInput.mediaUrl)) {
    throw new Error('Invalid media URL');
  }
};

Rate Limiting with Utilities

import { debounce, delay, chunk } from 'whatsapp-client-sdk';

// Debounce rapid user interactions
const debouncedHandler = debounce(async (userPhone: string, action: string) => {
  await handleUserAction(userPhone, action);
}, 1000);

// Batch processing with delays
const sendBulkNotifications = async (users: User[], message: string) => {
  const batches = chunk(users, 20);
  
  for (let i = 0; i < batches.length; i++) {
    const batch = batches[i];
    
    await Promise.all(
      batch.map(user => client.sendText(user.phone, message))
    );
    
    // Don't delay after the last batch
    if (i < batches.length - 1) {
      console.log(`Batch ${i + 1}/${batches.length} completed, waiting...`);
      await delay(5000); // 5 second delay between batches
    }
  }
};

This utility system provides essential building blocks for robust WhatsApp message processing, input validation, and error handling.

Core Components

Communication Methods

System Components

Utility Functions & Helpers

Utility Functions & Helpers

Phone Number Utilities

formatPhoneNumber()

validatePhoneNumber()

Retry Logic & Error Handling

withRetry()

delay()

Text Processing

truncateText()

sanitizeText()

URL Utilities

isValidUrl()

Array Utilities

chunk()

JSON Utilities

safeJsonParse()

Function Utilities

debounce()

Usage Examples

Comprehensive Message Processing

Input Validation and Sanitization

Rate Limiting with Utilities

Core Components

Communication Methods

System Components

​Utility Functions & Helpers

​Phone Number Utilities

​formatPhoneNumber()

​validatePhoneNumber()

​Retry Logic & Error Handling

​withRetry()

​delay()

​Text Processing

​truncateText()

​sanitizeText()

​URL Utilities

​isValidUrl()

​Array Utilities

​chunk()

​JSON Utilities

​safeJsonParse()

​Function Utilities

​debounce()

​Usage Examples

​Comprehensive Message Processing

​Input Validation and Sanitization

​Rate Limiting with Utilities

Utility Functions & Helpers

Phone Number Utilities

formatPhoneNumber()

validatePhoneNumber()

Retry Logic & Error Handling

withRetry()

delay()

Text Processing

truncateText()

sanitizeText()

URL Utilities

isValidUrl()

Array Utilities

chunk()

JSON Utilities

safeJsonParse()

Function Utilities

debounce()

Usage Examples

Comprehensive Message Processing

Input Validation and Sanitization

Rate Limiting with Utilities