Clone this repo:
  1. f15c970 Remove an unused argument of utility test func (#139) by haya14busa · 5 weeks ago master
  2. 2b3a18b travis: add 1.9.x to go versions (#133) by Davor Kapsa · 3 months ago
  3. c605e28 Add doc comment for exported Format func (#115) by Matthew Hardwick · 7 months ago
  4. ff09b13 Bump Go versions, use latest patch releases (#110) by Alexey Palazhchenko · 8 months ago
  5. bfd5150 Move benchmark assigned err to global exported variable (#106) by Bradley Falzon · 9 months ago

errors Travis-CI AppVeyor GoDoc Report card

Package errors provides simple error handling primitives.

go get github.com/pkg/errors

The traditional error handling idiom in Go is roughly akin to

if err != nil {
        return err
}

which applied recursively up the call stack results in error reports without context or debugging information. The errors package allows programmers to add context to the failure path in their code in a way that does not destroy the original value of the error.

Adding context to an error

The errors.Wrap function returns a new error that adds context to the original error. For example

_, err := ioutil.ReadAll(r)
if err != nil {
        return errors.Wrap(err, "read failed")
}

Retrieving the cause of an error

Using errors.Wrap constructs a stack of errors, adding context to the preceding error. Depending on the nature of the error it may be necessary to reverse the operation of errors.Wrap to retrieve the original error for inspection. Any error value which implements this interface can be inspected by errors.Cause.

type causer interface {
        Cause() error
}

errors.Cause will recursively retrieve the topmost error which does not implement causer, which is assumed to be the original cause. For example:

switch err := errors.Cause(err).(type) {
case *MyError:
        // handle specifically
default:
        // unknown error
}

Read the package documentation for more information.

Contributing

We welcome pull requests, bug fixes and issue reports. With that said, the bar for adding new symbols to this package is intentionally set high.

Before proposing a change, please discuss your change by raising an issue.

Licence

BSD-2-Clause