How to catch UrlFetchApp.fetch exception

Question

Is there any way to catch the exception from UrlFetchApp.fetch?

I thought I can use response.getResponseCode() to check the response code,

Answer 1

The trick is passing the muteHttpExceptions param of UrlFetchApp.fetch().

Here an example (untested):

var payload = {"value": "key"}
var response = UrlFetchApp.fetch(
            url,
            {
              method: "PUT",
              contentType: "application/json",
              payload: JSON.stringify(payload),
              muteHttpExceptions: true,
            }
          );
var responseCode = response.getResponseCode()
var responseBody = response.getContentText()

if (responseCode === 200) {
  var responseJson = JSON.parse(responseBody)
  // ...
} else {
  Logger.log(Utilities.formatString("Request failed. Expected 200, got %d: %s", responseCode, responseBody))
  // ...
}

For some reason if the URL is not available (e.g. the service you're trying to use is down) it still looks like is throwing an error so you may still need to use a try/catch block.