App Script to check if contact exists always returns contact does NOT exist

I am trying to check if a contact exists (by comparing first and last names) to avoid creating duplicate contacts. If it doesn't exist, I want to create the contact. When I run the code, I do not get an error. However, it states that the contact doesn't exist and creates it, even though the contact does exist. It is not able to find the contact and/or correctly compare it. Please help me find my error.

function checkAndCreateContactsFromSpreadsheet() {

  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Contacts'); // Your sheet name
  var data = sheet.getDataRange().getValues(); // Get all data from the sheet

  for (var i = 1; i < data.length; i++) { // Skip header row
    var firstName = data[i][1];
    var lastName = data[i][0];
    var email = data[i][12];

  if (firstName && lastName) {
     var contact = findContactByName(firstName, lastName); // Check if contact exists by name
     
     if (contact) {
       Logger.log('Contact exists: ' + contact.names[0].displayName);
     } else {
       Logger.log('Contact does not exist. Creating new contact...');
      createContact(firstName, lastName, email); // Create contact if it doesn't exist
      }
   }
  }
}


function findContactByName(firstName, lastName) {
 
  try {
  
    const response = People.People.get('people/me', {personFields: 'names'});

    var connections = response.connections || [];
    for (var i = 0; i < connections.length; i++) {
      var person = connections[i];
      if (person.names) {
        // Check if the first name and last name match
        for (var j = 0; j < person.names.length; j++) {
          var fullName = person.names[j].displayName.split(' ');
          if (fullName[0].toLowerCase() === firstName.toLowerCase() && fullName[1].toLowerCase() === lastName.toLowerCase()) {
            return person; // Return contact if first and last name match
            
          }
        }
      }
    }
    return null; // Return null if no contact matches
  } catch (e) {
    Logger.log('Error finding contact: ' + e.message);
    return null;
  }
}

function createContact(firstName, lastName, email) {
  try {
    var newContact = {
      names: [{ givenName: firstName, familyName: lastName }],
      emailAddresses: [{ value: email }]
    };

    // Create the new contact using People API
    var createdContact = People.People.createContact(newContact);
    Logger.log('Created new contact: ' + createdContact.names[0].displayName);
  } catch (e) {
    Logger.log('Error creating contact: ' + e.message);
  }
}

Use Connections instead of Get in People API

I removed your people.get and modified your connection.list to make the conditional statement work. I use connection.list to get all your current contacts then added if condition to match if the firstname and lastname are within the list and using forEach to iterate each list in your Contacts.

Modified Code:

function checkAndCreateContactsFromSpreadsheet() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Contacts'); // Your sheet name
  var data = sheet.getDataRange().getValues(); // Get all data from the sheet

  for (var i = 1; i < data.length; i++) { // Skip header row
    var firstName = data[i][1];
    var lastName = data[i][0];
    var email = data[i][12];

    if (firstName && lastName) {
      var contact = findContactByName(firstName, lastName); // Check if contact exists by name
      if (contact.length != 0) {
        Logger.log('Contact exists: ' + contact[0].names[0].displayName);
      } else {
        Logger.log('Contact does not exist. Creating new contact...');
        createContact(firstName, lastName, email); // Create contact if it doesn't exist
      }
    }
  }
}

function findContactByName(firstName, lastName) {
  // Using Poeple Connection List.
  const connections = People.People.Connections.list('people/me', {
    pageSize: 30,
    personFields: 'names,emailAddresses'
  });

  let contacts = [];
  connections.connections.forEach((person) => {
    // if contacts/connections is available, print the name of person.
    if (person.names && person.names.length === 0) {
      console.log('No display name found for connection.');
      return false;
    }
    const [name, lastname] = [person.names[0].givenName, person.names[0].familyName]
    
    // If matches then return the current iteration to varaible contacts on checkAndCreateContactsFromSpreadsheet function.
    if (firstName == name && lastName == lastname) {
      contacts.push(person)
      return
    }
  });
return contacts;
}

function createContact(firstName, lastName, email) {
  try {
    var newContact = {
      names: [{ givenName: firstName, familyName: lastName }],
      emailAddresses: [{ value: email }]
    };

    // Create the new contact using People API
    var createdContact = People.People.createContact(newContact);
    Logger.log('Created new contact: ' + createdContact.names[0].displayName);
  } catch (e) {
    Logger.log('Error creating contact: ' + e.message);
  }
}

Reference:

• People API Google Apps Script quickstart