Support unwrapping error

[jaycetde]

Description

Support unwrapping errors using errors.Unwrap from standard library. Supporting unwrap will also allow errors.Is to work:

import (
	"errors"
	bserrors "github.com/bugsnag/bugsnag-go/v2/errors"
)

var MyErr = errors.New("my error")

wrappedErr := bserrors.Errorf("wrapped: %w", MyErr)

if errors.Is(wrappedErr, MyErr) {
  // Custom logic here
}

Describe the solution you'd like
Add the following to errors/error.go:

func (err *Error) Unwrap() error {
	return err.Err
}

or possibly:

func (err *Error) Unwrap() error {
	return errors.Unwrap(err.Err)
}

[luke-belton]

Hi @jaycetde - thanks for raising this. We've added an item to our product roadmap to work on this in the future. I don't currently have an ETA, but we'll keep this thread updated 👍

[luke-belton]

Hi @jaycetde - just wanted to follow up on this to say we're unlikely to prioritise this work in the immediate future, but we would be willing to accept a contribution if you're interested. We'd want to go for your second proposed solution, i.e.

func (err *Error) Unwrap() error {
	return errors.Unwrap(err.Err)
}

The solution would also need to have a simple test to cover it 👍

[luke-belton]

Hi @jaycetde - thanks again for this, support for this was released in v1.9.1 of bugsnag-go 👍