Node:internal/process/promises:288 triggeruncaughtexception(err, true /* frompromise */);

Description

The code snippet “node:internal/process/promises:288 triggeruncaughtexception(err, true /* frompromise */);” is an internal event handler for unhandled promise rejections in the Node.js environment. It is triggered whenever an unhandled promise is rejected, causing an uncaught exception.

Explanation

1. node:internal/process/promises:288: The code is referencing a specific file and line number within the internal Node.js process module responsible for handling promises. This file/module is responsible for managing promise-related operations and events.
2. triggeruncaughtexception(err, true /* frompromise */): This is the specific function or event being triggered within the referenced module. It takes two arguments:
   • err: The error object representing the rejected promise. This object typically contains details about the error that occurred.
   • true /* frompromise */: A flag indicating that the error originated from a promise. This can be used to differentiate between errors from different sources.

   When this function is called, it handles the uncaught exception by performing some internal logic or triggering additional error handling mechanisms.

Example

    
      const promise = new Promise((resolve, reject) => {
        setTimeout(() => {
          reject(new Error('Promise rejected!'));
        }, 2000);
      });

      // Since no error handling is done for the promise, it will result in an unhandled rejection

      // Output:
      // node:internal/process/promises:288 triggeruncaughtexception(err, true /* frompromise */);
    
  

In this example, a promise is created with a timeout of 2 seconds. After the timeout, the promise is rejected with an error. As no error handling is done for the promise, it becomes an unhandled rejection and triggers the event handler “node:internal/process/promises:288 triggeruncaughtexception(err, true /* frompromise */);”. This event handler will handle the uncaught exception internally or trigger additional error handling mechanisms.