Google Apps Script:
Writing to standard error

How to:

Google Apps Script, being a scripting language for light-weight application development in the Google Apps platform, does not provide a direct built-in function like console.error() for writing to stderr, as you might find in Node.js or Python. However, you can simulate this behavior by using Google Apps Script’s logging services or custom error handling to manage and segregate error outputs.

Example: Using Logger for Error Messages

function logError() {
  try {
    // Simulate an error
    const result = 1 / 0;
    if(!isFinite(result)) throw new Error("Attempted division by zero");
  } catch (e) {
    // Write error message to Logs
    Logger.log('Error: ' + e.message);
  }
}

When you run logError(), this will write the error message to Google Apps Script’s log, which you can view by View > Logs. This isn’t exactly stderr, but it serves a similar purpose of separating error logs from standard outputs.

Advanced Diagnostic Logging

For more advanced debugging and error logging, you can use Stackdriver Logging, now known as Google Cloud’s Operations Suite.

function advancedErrorLogging() {
  try {
    // Cause an error deliberately
    const obj = null;
    const result = obj.someProperty;
  } catch (e) {
    console.error('Error encountered: ', e.toString());
  }
}

This will direct the error message to Stackdriver Logging, where it’s managed as an error-level log. Note that Stackdriver/Google Cloud’s Operations Suite integration offers a more granular and searchable logging solution compared to Logger.

Deep Dive

The lack of a dedicated stderr stream in Google Apps Script reflects its nature and origins as a cloud-based scripting language, where traditional console or terminal-based outputs (like stdout and stderr) are less relevant. Historically, Google Apps Script was designed for enhancing Google Apps functionality with simple scripts, focusing on ease of use over comprehensive features available in more complex programming environments.

That said, the evolution of Google Apps Script towards more sophisticated application development has prompted developers to adopt creative approaches for error handling and logging, utilizing available services like Logger and integrating with Google Cloud’s Operations Suite. These methods, while not direct stderr implementations, offer robust alternatives for error management and diagnostic logging in a cloud-centric environment.

Critically, while these methods serve the purpose within Google Apps Script’s ecosystem, they underscore the platform’s limitations compared to traditional programming environments. For developers requiring detailed and hierarchical error handling strategies, integrating with external logging services or adopting Google Cloud Functions, which offer a more conventional stderr and stdout handling, might be preferable.