File upload in sharepoint list after the items created using jquery

Hi
I tried to add item in sharepoint list and then using the id tried to upload. The problem here is when i do debug the attachment is added to the item. If i run normally attachment has not added.

<script>
createTask = function () {
  
  var x = $scope.task;
  var call = addItemFields(x);
  call.done(function (data, textStatus, jqXHR) {
  var item = data.d;
  

  function uploadDocument() {
  var element = document.getElementById("inputFile");
  var file = element.files[0];
  var parts = element.value.split("\\");
  var fileName = parts[parts.length - 1];

  var reader = new FileReader();
  reader.onload = function (e) {
  addItem(e.target.result, fileName, item);
  }
  reader.onerror = function (e) {
  alert(e.target.error);
  }
  reader.readAsArrayBuffer(file);


  function addItem(buffer, fileName, item) {
  var call2 = uploadDocument(buffer, fileName, item);
  call2.done(function (data, textStatus, jqXHR) {
  alert("successfully uploaded");
  });
  call2.fail(function (jqXHR, textStatus, errorThrown) {
  failHandler(jqXHR, textStatus, errorThrown);
  });

  }


  
  });
  call.fail(function (jqXHR, textStatus, errorThrown) {
  failHandler(jqXHR, textStatus, errorThrown);
  });

  }
  
  function uploadDocument(buffer, fileName, item) {

  var url = _spPageContextInfo.webAbsoluteUrl + "/_api/web/lists/GetByTitle('MeetingTasks')/items(" + item.Id + ")/AttachmentFiles/add(FileName='" + fileName + "')";
  var call = jQuery.ajax({
  url: url,
  type: "POST",
  data: buffer,
  processData: false,
  headers: {
  Accept: "application/json;odata=verbose",
  "X-RequestDigest": jQuery("#__REQUESTDIGEST").val(),
  "Content-Length": buffer.byteLength,
  "IF-MATCH": item.__metadata.etag,
  "X-Http-Method": "MERGE"
  }
  });

  return call;

  }


  function failHandler(jqXHR, textStatus, errorThrown) {
  var response = JSON.parse(jqXHR.responseText);
  var message = response ? response.error.message.value : textStatus;
  alert("Call failed. Error: " + message);
  }




  function addItemFields(item) {
  var now = new Date();
  var call = jQuery.ajax({
  url: _spPageContextInfo.webAbsoluteUrl +
  "/_api/Web/Lists/getByTitle('MeetingTasks')/Items",
  type: "POST",
  data: JSON.stringify({
  "__metadata": { type: "SP.Data.MeetingTasksListItem" },
  Title: item.taskName,
  Body: item.description, DueDate: item.dueDate
  }),
  headers: {
  Accept: "application/json;odata=verbose",
  "Content-Type": "application/json;odata=verbose",
  "X-RequestDigest": jQuery("#__REQUESTDIGEST").val()
  }
  });

  return call;
  }

  });
</script>

HTML:

regards
jhanani