Mastering JavaScript Functional Programming - Second Edition

Taking exceptions into account

Let's enhance our logging function a bit by considering an adjustment. What happens to your log if the function throws an error? Fortunately, this is easy to solve. We just have to add a try/catch structure, as shown in the following code:

const addLogging2 = fn => (...args) => {  console.log(`entering ${fn.name}: ${args}`);  try {    const valueToReturn = fn(...args);    console.log(`exiting ${fn.name}: ${valueToReturn}`);    return valueToReturn;  } catch (thrownError) {    console.log(`exiting ${fn.name}: threw ${thrownError}`);    throw thrownError;  }};

With this change, if the function threw an error, you'd also get an appropriate logging message, and the exception would be rethrown for processing.

Other changes to get ...