Contextual Debugging with Error Cause

Snippet

Contextual Debugging with Error Cause

The 'cause' property in the Error constructor allows you to wrap lower-level errors in higher-level context without losing the original stack trace or error details. This is essential for debugging complex flows in Node.js backends.

snippet.js
javascript
async function processOrder(orderId) {
  try {
    await db.save(orderId);
  } catch (err) {
    throw new Error(`Failed to process order ${orderId}`, {
      cause: err
    });
  }
}
 
// Catching:
try {
  await processOrder(123);
} catch (err) {
  console.error(err.message); // High-level message
  console.error(err.cause);   // Original database error
}

nodejs

Breakdown

throw new Error(..., { cause: err });

Wraps the original error inside a new Error using the options object.

console.error(err.cause);

Accesses the underlying error that triggered the failure.

Previous snippet Next snippet

More Intermediate JavaScript exercises →

From your library

Contextual Debugging with Error Cause

Related