Add/Update with SP Http Client

AddUpdateSPHttpClient.ts

try
{
let addorUpdateObj : any = {
              AuthorId : customObj.user.id,
              __metadata : {
                      'type': `SP.Data.CustomListItem`
              }   
          }
          
console.log(`Sending object ${addorUpdateObj}`);
let body: string = JSON.stringify(addorUpdateObj);
let spHttpClient : SPHttpClient = context.spHttpClient;
let postURL: string = `${context.pageContext.web.absoluteUrl}/_api/web/lists/GetByTitle('${listTitle}')/Items` ;
let Action = 'POST';

  if(customObj.id !== 0)
  {                     
      postURL = postURL + `('${customObj.id}')`;
      Action = 'MERGE';
      console.log(`update called ${postURL}`);
      spHttpClient.post(postURL,
      SPHttpClient.configurations.v1,
      {
        headers: {
          'Accept': 'application/json;odata=nometadata',
          'Content-type': 'application/json;odata=verbose',
          'odata-version': '',
          'IF-MATCH': '*',
          'X-HTTP-Method': Action
        },
        body: body
        }).then((response: SPHttpClientResponse) => {
        console.log('Save result ' + response.ok);
        if(response.ok)
        {
          resolve(true);
        }
        else
          reject("Error while saving data");
      });
  }
  else
  {
    console.log(`add called ${postURL}`);
    spHttpClient.post(postURL,
    SPHttpClient.configurations.v1,
    {
      headers: {
        'Accept': 'application/json;odata=verbose',
        'Content-type': 'application/json;odata=verbose',
        'odata-version': ''
      },
      body: body
      }).then((response: SPHttpClientResponse) => {
      console.log('Save result ' + response.ok);
      if(response.ok)
      {
        resolve(true);
      }
      else
        reject("Error while saving data");
    });
  }
} catch(error)
{
  console.log(error);
  throw(error);
}