TypeScript:
Writing to standard error

How to:

TypeScript, being a superset of JavaScript, relies on the underlying JS runtime environment (like Node.js) for writing to stderr. Here’s how you can do it directly:

console.error("This is an error message.");

Sample output to stderr:

This is an error message.

In a Node.js environment, you can also use the process.stderr.write() method for more low-level writing:

process.stderr.write("Low level error message.\n");

Sample output to stderr:

Low level error message.

For more structured error logging, you might use popular third-party libraries such as winston or pino. Here’s how to log errors using winston:

First, install winston:

npm install winston

Then use it in your TypeScript file:

import * as winston from 'winston';

const logger = winston.createLogger({
  levels: winston.config.syslog.levels,
  transports: [
    new winston.transports.Console(),
    new winston.transports.File({ filename: 'error.log', level: 'error' })
  ],
});

logger.error('Error logged using winston.');

This will write the error to both the console and a file named error.log. Remember, when writing to files, it’s important to manage file permissions and rollover to prevent issues related to disk space.usage.