Mastering JavaScript Functional Programming

Taking exceptions into account

Let's enhance our logging function a bit, by considering a needed adjustment. What happens to your log if the function throws an error? Fortunately, that's easy to solve. We just have to add some 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;    }};

Other changes would be up to you -- adding date and time data, enhancing the way parameters are listed, and so on. However, our implementation still has an important defect; let's make it better.