errors

Because there is a limit to this insanity.

What is this?

This library extends the errors package from the standard library with two well-known methods: Wrap and Wrapf.

func Wrap(err error, message string) error {
	...
}

func Wrapf(err error, format string, args ...interface{}) error {
	...
}

Why?

The Go Blog helpfully recommends writing the following in order to wrap an error:

if err != nil {
    return fmt.Errorf("decompress %v: %w", name, err)
}

Well, my (and hopefully your) response to this is "No, thank you Mr. Pike!".

Thanks to this library you can continue using the old approach:

if err != nil {
    return errors.Wrapf(err, "decompress %v", name)
}

The second version is in my opinion much more readable as well as idiomatic - and as far as I know the only reason for not going with this approach in the standard library was the aversion to forcing every single Go program in the world to import fmt whenever errors is imported. There are other funny situations in the standard library caused by avoiding dependencies.

Why not github.com/pkg/errors?

Unfortunately github.com/pkg/errors is incompatibile with the new methods available in the standard library such as errors.Is(...).