How to fix messaging/INVALID_ARGUMENT: Request parameters invalid in Firebase

// Example of checking token format
const token = 'your-fcm-token-here';

// Basic validation - tokens should be a long string
if (!token || typeof token !== 'string') {
  console.error('Token is missing or not a string');
}

// Check approximate length (FCM tokens are typically 152+ characters)
if (token.length < 100) {
  console.error('Token appears too short, may be truncated');
}

// Check for common issues
if (token.includes(' ') || token.includes('\n')) {
  console.error('Token contains whitespace or newlines');
}

// Example message structure validation
const message = {
  token: registrationToken,
  notification: {
    title: 'Notification Title',
    body: 'Notification body text'
  },
  data: {
    // Data payload - limited to 4096 bytes total
    key1: 'value1',
    key2: 'value2'
  },
  android: {
    // Android-specific options
  },
  apns: {
    // iOS-specific options
  }
};

// Calculate payload size
const payloadSize = JSON.stringify(message).length;
console.log('Payload size: ' + payloadSize + ' bytes');

if (payloadSize > 4096) {
  console.error('Payload exceeds 4096 byte limit');
  // Reduce data payload or remove optional fields
}

// Check for forbidden keys in data payload
const forbiddenKeys = ['from', 'gcm', 'google', 'collapse_key'];
const dataKeys = Object.keys(message.data || {});
forbiddenKeys.forEach(forbidden => {
  if (dataKeys.some(key => key.startsWith(forbidden))) {
    console.error('Data payload contains forbidden key starting with "' + forbidden + '"');
  }
});

// Correct FCM v1 endpoint
const fcmEndpoint = 'https://fcm.googleapis.com/v1/projects/{project_id}/messages:send';

// For Firebase Admin SDK, ensure proper initialization
const admin = require('firebase-admin');

// Initialize with service account credentials
admin.initializeApp({
  credential: admin.credential.applicationDefault(),
  // or: admin.credential.cert(serviceAccount)
});

// Send message
const messaging = admin.messaging();
await messaging.send(message);

// Minimal test message
const testMessage = {
  token: registrationToken,
  notification: {
    title: 'Test',
    body: 'Test message'
  }
};

try {
  const response = await messaging.send(testMessage);
  console.log('Minimal message sent successfully:', response);

  // If minimal works, gradually add back your original configuration
  // to identify which parameter causes the error
} catch (error) {
  console.error('Error with minimal message:', error.message);

  // Check error details
  if (error.errorInfo) {
    console.error('Error details:', error.errorInfo);
  }
}

// For Firebase Admin SDK, enable debug logging
process.env.DEBUG = 'firebase-admin:*';

// Or catch and log full error details
try {
  await messaging.send(message);
} catch (error) {
  console.error('Full error object:', JSON.stringify(error, null, 2));

  // Check for specific error codes
  if (error.code === 'messaging/invalid-argument') {
    console.error('Invalid argument details:', error.details);
  }
}