Drop dependency github.com/juju/errors

This commit is contained in:
Alexander Neumann 2016-08-21 17:24:13 +02:00
parent 24385ff56e
commit 17a38faa43
22 changed files with 28 additions and 2381 deletions

View file

@ -14,8 +14,6 @@ import (
"restic/repository"
"restic/worker"
"github.com/juju/errors"
)
type CmdDump struct {

View file

@ -2,6 +2,7 @@ package restic
import (
"encoding/json"
"errors"
"fmt"
"io"
"os"
@ -18,8 +19,6 @@ import (
"restic/repository"
"github.com/restic/chunker"
"github.com/juju/errors"
)
const (
@ -230,7 +229,7 @@ func (arch *Archiver) SaveFile(p *Progress, node *Node) error {
}
if err != nil {
return errors.Annotate(err, "SaveFile() chunker.Next()")
return err
}
resCh := make(chan saveResult, 1)

View file

@ -4,6 +4,7 @@ import (
"bufio"
"crypto/rand"
"encoding/hex"
"errors"
"fmt"
"io"
"os"
@ -15,7 +16,6 @@ import (
"restic/backend"
"restic/debug"
"github.com/juju/errors"
"github.com/pkg/sftp"
)
@ -206,9 +206,8 @@ func (r *SFTP) tempFile() (string, *sftp.File, error) {
buf := make([]byte, tempfileRandomSuffixLength)
_, err := io.ReadFull(rand.Reader, buf)
if err != nil {
return "", nil, errors.Annotatef(err,
"unable to read %d random bytes for tempfile name",
tempfileRandomSuffixLength)
return "", nil, fmt.Errorf("unable to read %d random bytes for tempfile name: %v",
tempfileRandomSuffixLength, err)
}
// construct tempfile name
@ -217,7 +216,7 @@ func (r *SFTP) tempFile() (string, *sftp.File, error) {
// create file in temp dir
f, err := r.c.Create(name)
if err != nil {
return "", nil, errors.Annotatef(err, "creating tempfile %q failed", name)
return "", nil, fmt.Errorf("creating tempfile %q failed: %v", name, err)
}
return name, f, nil

View file

@ -17,8 +17,6 @@ import (
"restic/fs"
"restic/pack"
"restic/repository"
"github.com/juju/errors"
)
// Node is a file, directory or other item in a backup.
@ -114,27 +112,27 @@ func (node *Node) CreateAt(path string, repo *repository.Repository) error {
switch node.Type {
case "dir":
if err := node.createDirAt(path); err != nil {
return errors.Annotate(err, "createDirAt")
return err
}
case "file":
if err := node.createFileAt(path, repo); err != nil {
return errors.Annotate(err, "createFileAt")
return err
}
case "symlink":
if err := node.createSymlinkAt(path); err != nil {
return errors.Annotate(err, "createSymlinkAt")
return err
}
case "dev":
if err := node.createDevAt(path); err != nil {
return errors.Annotate(err, "createDevAt")
return err
}
case "chardev":
if err := node.createCharDevAt(path); err != nil {
return errors.Annotate(err, "createCharDevAt")
return err
}
case "fifo":
if err := node.createFifoAt(path); err != nil {
return errors.Annotate(err, "createFifoAt")
return err
}
case "socket":
return nil
@ -155,13 +153,13 @@ func (node Node) restoreMetadata(path string) error {
err = lchown(path, int(node.UID), int(node.GID))
if err != nil {
return errors.Annotate(err, "Lchown")
return err
}
if node.Type != "symlink" {
err = fs.Chmod(path, node.Mode)
if err != nil {
return errors.Annotate(err, "Chmod")
return err
}
}
@ -191,7 +189,7 @@ func (node Node) RestoreTimestamps(path string) error {
}
if err := syscall.UtimesNano(path, utimes[:]); err != nil {
return errors.Annotate(err, "UtimesNano")
return err
}
return nil
@ -200,7 +198,7 @@ func (node Node) RestoreTimestamps(path string) error {
func (node Node) createDirAt(path string) error {
err := fs.Mkdir(path, node.Mode)
if err != nil {
return errors.Annotate(err, "Mkdir")
return err
}
return nil
@ -211,7 +209,7 @@ func (node Node) createFileAt(path string, repo *repository.Repository) error {
defer f.Close()
if err != nil {
return errors.Annotate(err, "OpenFile")
return err
}
var buf []byte
@ -228,12 +226,12 @@ func (node Node) createFileAt(path string, repo *repository.Repository) error {
buf, err := repo.LoadBlob(id, pack.Data, buf)
if err != nil {
return errors.Annotate(err, "Load")
return err
}
_, err = f.Write(buf)
if err != nil {
return errors.Annotate(err, "Write")
return err
}
}
@ -247,7 +245,7 @@ func (node Node) createSymlinkAt(path string) error {
}
err := fs.Symlink(node.LinkTarget, path)
if err != nil {
return errors.Annotate(err, "Symlink")
return err
}
return nil
@ -422,7 +420,7 @@ func (node *Node) fillUser(stat statT) error {
username, err := lookupUsername(strconv.Itoa(int(stat.uid())))
if err != nil {
return errors.Annotate(err, "fillUser")
return err
}
node.User = username
@ -470,7 +468,7 @@ func (node *Node) fillExtra(path string, fi os.FileInfo) error {
var err error
if err = node.fillUser(stat); err != nil {
return errors.Annotate(err, "fillExtra")
return err
}
switch node.Type {

View file

@ -6,8 +6,6 @@ import (
"unsafe"
"restic/fs"
"github.com/juju/errors"
)
func (node Node) restoreSymlinkTimestamps(path string, utimes [2]syscall.Timespec) error {
@ -20,7 +18,7 @@ func (node Node) restoreSymlinkTimestamps(path string, utimes [2]syscall.Timespe
err = utimesNanoAt(int(dir.Fd()), filepath.Base(path), utimes, AT_SYMLINK_NOFOLLOW)
if err != nil {
return errors.Annotate(err, "UtimesNanoAt")
return err
}
return nil

View file

@ -9,8 +9,6 @@ import (
"restic/debug"
"restic/fs"
"restic/repository"
"github.com/juju/errors"
)
// Restorer is used to restore a snapshot to a directory.
@ -35,7 +33,7 @@ func NewRestorer(repo *repository.Repository, id backend.ID) (*Restorer, error)
r.sn, err = LoadSnapshot(repo, id)
if err != nil {
return nil, errors.Annotate(err, "load snapshot for restorer")
return nil, err
}
return r, nil
@ -44,7 +42,7 @@ func NewRestorer(repo *repository.Repository, id backend.ID) (*Restorer, error)
func (res *Restorer) restoreTo(dst string, dir string, treeID backend.ID) error {
tree, err := LoadTree(res.repo, treeID)
if err != nil {
return res.Error(dir, nil, errors.Annotate(err, "LoadTree"))
return res.Error(dir, nil, err)
}
for _, node := range tree.Nodes {
@ -67,7 +65,7 @@ func (res *Restorer) restoreTo(dst string, dir string, treeID backend.ID) error
subp := filepath.Join(dir, node.Name)
err = res.restoreTo(dst, subp, *node.Subtree)
if err != nil {
err = res.Error(subp, node, errors.Annotate(err, "restore subtree"))
err = res.Error(subp, node, err)
if err != nil {
return err
}
@ -96,7 +94,7 @@ func (res *Restorer) restoreNodeTo(node *Node, dir string, dst string) error {
}
// Did it fail because of ENOENT?
if err != nil && os.IsNotExist(errors.Cause(err)) {
if err != nil && os.IsNotExist(err) {
debug.Log("Restorer.restoreNodeTo", "create intermediate paths")
// Create parent directories and retry
@ -108,7 +106,7 @@ func (res *Restorer) restoreNodeTo(node *Node, dir string, dst string) error {
if err != nil {
debug.Log("Restorer.restoreNodeTo", "error %v", err)
err = res.Error(dstPath, node, errors.Annotate(err, "create node"))
err = res.Error(dstPath, node, err)
if err != nil {
return err
}

6
vendor/manifest vendored
View file

@ -19,12 +19,6 @@
"revision": "1b89bf73cd2c3a911d7b2a279ab085c4a18cf539",
"branch": "HEAD"
},
{
"importpath": "github.com/juju/errors",
"repository": "https://github.com/juju/errors",
"revision": "4567a5e69fd3130ca0d89f69478e7ac025b67452",
"branch": "HEAD"
},
{
"importpath": "github.com/kr/fs",
"repository": "https://github.com/kr/fs",

View file

@ -1,191 +0,0 @@
All files in this repository are licensed as follows. If you contribute
to this repository, it is assumed that you license your contribution
under the same license unless you state otherwise.
All files Copyright (C) 2015 Canonical Ltd. unless otherwise specified in the file.
This software is licensed under the LGPLv3, included below.
As a special exception to the GNU Lesser General Public License version 3
("LGPL3"), the copyright holders of this Library give you permission to
convey to a third party a Combined Work that links statically or dynamically
to this Library without providing any Minimal Corresponding Source or
Minimal Application Code as set out in 4d or providing the installation
information set out in section 4e, provided that you comply with the other
provisions of LGPL3 and provided that you meet, for the Application the
terms and conditions of the license(s) which apply to the Application.
Except as stated in this special exception, the provisions of LGPL3 will
continue to comply in full to this Library. If you modify this Library, you
may apply this exception to your version of this Library, but you are not
obliged to do so. If you do not wish to do so, delete this exception
statement from your version. This exception does not (and cannot) modify any
license terms which apply to the Application, with which you must still
comply.
GNU LESSER GENERAL PUBLIC LICENSE
Version 3, 29 June 2007
Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
This version of the GNU Lesser General Public License incorporates
the terms and conditions of version 3 of the GNU General Public
License, supplemented by the additional permissions listed below.
0. Additional Definitions.
As used herein, "this License" refers to version 3 of the GNU Lesser
General Public License, and the "GNU GPL" refers to version 3 of the GNU
General Public License.
"The Library" refers to a covered work governed by this License,
other than an Application or a Combined Work as defined below.
An "Application" is any work that makes use of an interface provided
by the Library, but which is not otherwise based on the Library.
Defining a subclass of a class defined by the Library is deemed a mode
of using an interface provided by the Library.
A "Combined Work" is a work produced by combining or linking an
Application with the Library. The particular version of the Library
with which the Combined Work was made is also called the "Linked
Version".
The "Minimal Corresponding Source" for a Combined Work means the
Corresponding Source for the Combined Work, excluding any source code
for portions of the Combined Work that, considered in isolation, are
based on the Application, and not on the Linked Version.
The "Corresponding Application Code" for a Combined Work means the
object code and/or source code for the Application, including any data
and utility programs needed for reproducing the Combined Work from the
Application, but excluding the System Libraries of the Combined Work.
1. Exception to Section 3 of the GNU GPL.
You may convey a covered work under sections 3 and 4 of this License
without being bound by section 3 of the GNU GPL.
2. Conveying Modified Versions.
If you modify a copy of the Library, and, in your modifications, a
facility refers to a function or data to be supplied by an Application
that uses the facility (other than as an argument passed when the
facility is invoked), then you may convey a copy of the modified
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a) under this License, provided that you make a good faith effort to
ensure that, in the event an Application does not supply the
function or data, the facility still operates, and performs
whatever part of its purpose remains meaningful, or
b) under the GNU GPL, with none of the additional permissions of
this License applicable to that copy.
3. Object Code Incorporating Material from Library Header Files.
The object code form of an Application may incorporate material from
a header file that is part of the Library. You may convey such object
code under terms of your choice, provided that, if the incorporated
material is not limited to numerical parameters, data structure
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(ten or fewer lines in length), you do both of the following:
a) Give prominent notice with each copy of the object code that the
Library is used in it and that the Library and its use are
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b) Accompany the object code with a copy of the GNU GPL and this license
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You may convey a Combined Work under terms of your choice that,
taken together, effectively do not restrict modification of the
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engineering for debugging such modifications, if you also do each of
the following:
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the Library is used in it and that the Library and its use are
covered by this License.
b) Accompany the Combined Work with a copy of the GNU GPL and this license
document.
c) For a Combined Work that displays copyright notices during
execution, include the copyright notice for the Library among
these notices, as well as a reference directing the user to the
copies of the GNU GPL and this license document.
d) Do one of the following:
0) Convey the Minimal Corresponding Source under the terms of this
License, and the Corresponding Application Code in a form
suitable for, and under terms that permit, the user to
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conveyed under the terms of this License.
b) Give prominent notice with the combined library that part of it
is a work based on the Library, and explaining where to find the
accompanying uncombined form of the same work.
6. Revised Versions of the GNU Lesser General Public License.
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of the GNU Lesser General Public License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns.
Each version is given a distinguishing version number. If the
Library as you received it specifies that a certain numbered version
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View file

@ -1,11 +0,0 @@
default: check
check:
go test && go test -compiler gccgo
docs:
godoc2md github.com/juju/errors > README.md
sed -i 's|\[godoc-link-here\]|[![GoDoc](https://godoc.org/github.com/juju/errors?status.svg)](https://godoc.org/github.com/juju/errors)|' README.md
.PHONY: default check docs

View file

@ -1,536 +0,0 @@
# errors
import "github.com/juju/errors"
[![GoDoc](https://godoc.org/github.com/juju/errors?status.svg)](https://godoc.org/github.com/juju/errors)
The juju/errors provides an easy way to annotate errors without losing the
orginal error context.
The exported `New` and `Errorf` functions are designed to replace the
`errors.New` and `fmt.Errorf` functions respectively. The same underlying
error is there, but the package also records the location at which the error
was created.
A primary use case for this library is to add extra context any time an
error is returned from a function.
if err := SomeFunc(); err != nil {
return err
}
This instead becomes:
if err := SomeFunc(); err != nil {
return errors.Trace(err)
}
which just records the file and line number of the Trace call, or
if err := SomeFunc(); err != nil {
return errors.Annotate(err, "more context")
}
which also adds an annotation to the error.
When you want to check to see if an error is of a particular type, a helper
function is normally exported by the package that returned the error, like the
`os` package does. The underlying cause of the error is available using the
`Cause` function.
os.IsNotExist(errors.Cause(err))
The result of the `Error()` call on an annotated error is the annotations joined
with colons, then the result of the `Error()` method for the underlying error
that was the cause.
err := errors.Errorf("original")
err = errors.Annotatef(err, "context")
err = errors.Annotatef(err, "more context")
err.Error() -> "more context: context: original"
Obviously recording the file, line and functions is not very useful if you
cannot get them back out again.
errors.ErrorStack(err)
will return something like:
first error
github.com/juju/errors/annotation_test.go:193:
github.com/juju/errors/annotation_test.go:194: annotation
github.com/juju/errors/annotation_test.go:195:
github.com/juju/errors/annotation_test.go:196: more context
github.com/juju/errors/annotation_test.go:197:
The first error was generated by an external system, so there was no location
associated. The second, fourth, and last lines were generated with Trace calls,
and the other two through Annotate.
Sometimes when responding to an error you want to return a more specific error
for the situation.
if err := FindField(field); err != nil {
return errors.Wrap(err, errors.NotFoundf(field))
}
This returns an error where the complete error stack is still available, and
`errors.Cause()` will return the `NotFound` error.
## func AlreadyExistsf
``` go
func AlreadyExistsf(format string, args ...interface{}) error
```
AlreadyExistsf returns an error which satisfies IsAlreadyExists().
## func Annotate
``` go
func Annotate(other error, message string) error
```
Annotate is used to add extra context to an existing error. The location of
the Annotate call is recorded with the annotations. The file, line and
function are also recorded.
For example:
if err := SomeFunc(); err != nil {
return errors.Annotate(err, "failed to frombulate")
}
## func Annotatef
``` go
func Annotatef(other error, format string, args ...interface{}) error
```
Annotatef is used to add extra context to an existing error. The location of
the Annotate call is recorded with the annotations. The file, line and
function are also recorded.
For example:
if err := SomeFunc(); err != nil {
return errors.Annotatef(err, "failed to frombulate the %s", arg)
}
## func Cause
``` go
func Cause(err error) error
```
Cause returns the cause of the given error. This will be either the
original error, or the result of a Wrap or Mask call.
Cause is the usual way to diagnose errors that may have been wrapped by
the other errors functions.
## func DeferredAnnotatef
``` go
func DeferredAnnotatef(err *error, format string, args ...interface{})
```
DeferredAnnotatef annotates the given error (when it is not nil) with the given
format string and arguments (like fmt.Sprintf). If *err is nil, DeferredAnnotatef
does nothing. This method is used in a defer statement in order to annotate any
resulting error with the same message.
For example:
defer DeferredAnnotatef(&err, "failed to frombulate the %s", arg)
## func Details
``` go
func Details(err error) string
```
Details returns information about the stack of errors wrapped by err, in
the format:
[{filename:99: error one} {otherfile:55: cause of error one}]
This is a terse alternative to ErrorStack as it returns a single line.
## func ErrorStack
``` go
func ErrorStack(err error) string
```
ErrorStack returns a string representation of the annotated error. If the
error passed as the parameter is not an annotated error, the result is
simply the result of the Error() method on that error.
If the error is an annotated error, a multi-line string is returned where
each line represents one entry in the annotation stack. The full filename
from the call stack is used in the output.
first error
github.com/juju/errors/annotation_test.go:193:
github.com/juju/errors/annotation_test.go:194: annotation
github.com/juju/errors/annotation_test.go:195:
github.com/juju/errors/annotation_test.go:196: more context
github.com/juju/errors/annotation_test.go:197:
## func Errorf
``` go
func Errorf(format string, args ...interface{}) error
```
Errorf creates a new annotated error and records the location that the
error is created. This should be a drop in replacement for fmt.Errorf.
For example:
return errors.Errorf("validation failed: %s", message)
## func IsAlreadyExists
``` go
func IsAlreadyExists(err error) bool
```
IsAlreadyExists reports whether the error was created with
AlreadyExistsf() or NewAlreadyExists().
## func IsNotFound
``` go
func IsNotFound(err error) bool
```
IsNotFound reports whether err was created with NotFoundf() or
NewNotFound().
## func IsNotImplemented
``` go
func IsNotImplemented(err error) bool
```
IsNotImplemented reports whether err was created with
NotImplementedf() or NewNotImplemented().
## func IsNotSupported
``` go
func IsNotSupported(err error) bool
```
IsNotSupported reports whether the error was created with
NotSupportedf() or NewNotSupported().
## func IsNotValid
``` go
func IsNotValid(err error) bool
```
IsNotValid reports whether the error was created with NotValidf() or
NewNotValid().
## func IsUnauthorized
``` go
func IsUnauthorized(err error) bool
```
IsUnauthorized reports whether err was created with Unauthorizedf() or
NewUnauthorized().
## func Mask
``` go
func Mask(other error) error
```
Mask hides the underlying error type, and records the location of the masking.
## func Maskf
``` go
func Maskf(other error, format string, args ...interface{}) error
```
Mask masks the given error with the given format string and arguments (like
fmt.Sprintf), returning a new error that maintains the error stack, but
hides the underlying error type. The error string still contains the full
annotations. If you want to hide the annotations, call Wrap.
## func New
``` go
func New(message string) error
```
New is a drop in replacement for the standard libary errors module that records
the location that the error is created.
For example:
return errors.New("validation failed")
## func NewAlreadyExists
``` go
func NewAlreadyExists(err error, msg string) error
```
NewAlreadyExists returns an error which wraps err and satisfies
IsAlreadyExists().
## func NewNotFound
``` go
func NewNotFound(err error, msg string) error
```
NewNotFound returns an error which wraps err that satisfies
IsNotFound().
## func NewNotImplemented
``` go
func NewNotImplemented(err error, msg string) error
```
NewNotImplemented returns an error which wraps err and satisfies
IsNotImplemented().
## func NewNotSupported
``` go
func NewNotSupported(err error, msg string) error
```
NewNotSupported returns an error which wraps err and satisfies
IsNotSupported().
## func NewNotValid
``` go
func NewNotValid(err error, msg string) error
```
NewNotValid returns an error which wraps err and satisfies IsNotValid().
## func NewUnauthorized
``` go
func NewUnauthorized(err error, msg string) error
```
NewUnauthorized returns an error which wraps err and satisfies
IsUnauthorized().
## func NotFoundf
``` go
func NotFoundf(format string, args ...interface{}) error
```
NotFoundf returns an error which satisfies IsNotFound().
## func NotImplementedf
``` go
func NotImplementedf(format string, args ...interface{}) error
```
NotImplementedf returns an error which satisfies IsNotImplemented().
## func NotSupportedf
``` go
func NotSupportedf(format string, args ...interface{}) error
```
NotSupportedf returns an error which satisfies IsNotSupported().
## func NotValidf
``` go
func NotValidf(format string, args ...interface{}) error
```
NotValidf returns an error which satisfies IsNotValid().
## func Trace
``` go
func Trace(other error) error
```
Trace adds the location of the Trace call to the stack. The Cause of the
resulting error is the same as the error parameter. If the other error is
nil, the result will be nil.
For example:
if err := SomeFunc(); err != nil {
return errors.Trace(err)
}
## func Unauthorizedf
``` go
func Unauthorizedf(format string, args ...interface{}) error
```
Unauthorizedf returns an error which satisfies IsUnauthorized().
## func Wrap
``` go
func Wrap(other, newDescriptive error) error
```
Wrap changes the Cause of the error. The location of the Wrap call is also
stored in the error stack.
For example:
if err := SomeFunc(); err != nil {
newErr := &packageError{"more context", private_value}
return errors.Wrap(err, newErr)
}
## func Wrapf
``` go
func Wrapf(other, newDescriptive error, format string, args ...interface{}) error
```
Wrapf changes the Cause of the error, and adds an annotation. The location
of the Wrap call is also stored in the error stack.
For example:
if err := SomeFunc(); err != nil {
return errors.Wrapf(err, simpleErrorType, "invalid value %q", value)
}
## type Err
``` go
type Err struct {
// contains filtered or unexported fields
}
```
Err holds a description of an error along with information about
where the error was created.
It may be embedded in custom error types to add extra information that
this errors package can understand.
### func NewErr
``` go
func NewErr(format string, args ...interface{}) Err
```
NewErr is used to return an Err for the purpose of embedding in other
structures. The location is not specified, and needs to be set with a call
to SetLocation.
For example:
type FooError struct {
errors.Err
code int
}
func NewFooError(code int) error {
err := &FooError{errors.NewErr("foo"), code}
err.SetLocation(1)
return err
}
### func (\*Err) Cause
``` go
func (e *Err) Cause() error
```
The Cause of an error is the most recent error in the error stack that
meets one of these criteria: the original error that was raised; the new
error that was passed into the Wrap function; the most recently masked
error; or nil if the error itself is considered the Cause. Normally this
method is not invoked directly, but instead through the Cause stand alone
function.
### func (\*Err) Error
``` go
func (e *Err) Error() string
```
Error implements error.Error.
### func (\*Err) Location
``` go
func (e *Err) Location() (filename string, line int)
```
Location is the file and line of where the error was most recently
created or annotated.
### func (\*Err) Message
``` go
func (e *Err) Message() string
```
Message returns the message stored with the most recent location. This is
the empty string if the most recent call was Trace, or the message stored
with Annotate or Mask.
### func (\*Err) SetLocation
``` go
func (e *Err) SetLocation(callDepth int)
```
SetLocation records the source location of the error at callDepth stack
frames above the call.
### func (\*Err) StackTrace
``` go
func (e *Err) StackTrace() []string
```
StackTrace returns one string for each location recorded in the stack of
errors. The first value is the originating error, with a line for each
other annotation or tracing of the error.
### func (\*Err) Underlying
``` go
func (e *Err) Underlying() error
```
Underlying returns the previous error in the error stack, if any. A client
should not ever really call this method. It is used to build the error
stack and should not be introspected by client calls. Or more
specifically, clients should not depend on anything but the `Cause` of an
error.
- - -
Generated by [godoc2md](http://godoc.org/github.com/davecheney/godoc2md)

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@ -1,81 +0,0 @@
// Copyright 2013, 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
/*
[godoc-link-here]
The juju/errors provides an easy way to annotate errors without losing the
orginal error context.
The exported `New` and `Errorf` functions are designed to replace the
`errors.New` and `fmt.Errorf` functions respectively. The same underlying
error is there, but the package also records the location at which the error
was created.
A primary use case for this library is to add extra context any time an
error is returned from a function.
if err := SomeFunc(); err != nil {
return err
}
This instead becomes:
if err := SomeFunc(); err != nil {
return errors.Trace(err)
}
which just records the file and line number of the Trace call, or
if err := SomeFunc(); err != nil {
return errors.Annotate(err, "more context")
}
which also adds an annotation to the error.
When you want to check to see if an error is of a particular type, a helper
function is normally exported by the package that returned the error, like the
`os` package does. The underlying cause of the error is available using the
`Cause` function.
os.IsNotExist(errors.Cause(err))
The result of the `Error()` call on an annotated error is the annotations joined
with colons, then the result of the `Error()` method for the underlying error
that was the cause.
err := errors.Errorf("original")
err = errors.Annotatef(err, "context")
err = errors.Annotatef(err, "more context")
err.Error() -> "more context: context: original"
Obviously recording the file, line and functions is not very useful if you
cannot get them back out again.
errors.ErrorStack(err)
will return something like:
first error
github.com/juju/errors/annotation_test.go:193:
github.com/juju/errors/annotation_test.go:194: annotation
github.com/juju/errors/annotation_test.go:195:
github.com/juju/errors/annotation_test.go:196: more context
github.com/juju/errors/annotation_test.go:197:
The first error was generated by an external system, so there was no location
associated. The second, fourth, and last lines were generated with Trace calls,
and the other two through Annotate.
Sometimes when responding to an error you want to return a more specific error
for the situation.
if err := FindField(field); err != nil {
return errors.Wrap(err, errors.NotFoundf(field))
}
This returns an error where the complete error stack is still available, and
`errors.Cause()` will return the `NotFound` error.
*/
package errors

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@ -1,122 +0,0 @@
// Copyright 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors
import (
"fmt"
"reflect"
"runtime"
)
// Err holds a description of an error along with information about
// where the error was created.
//
// It may be embedded in custom error types to add extra information that
// this errors package can understand.
type Err struct {
// message holds an annotation of the error.
message string
// cause holds the cause of the error as returned
// by the Cause method.
cause error
// previous holds the previous error in the error stack, if any.
previous error
// file and line hold the source code location where the error was
// created.
file string
line int
}
// NewErr is used to return an Err for the purpose of embedding in other
// structures. The location is not specified, and needs to be set with a call
// to SetLocation.
//
// For example:
// type FooError struct {
// errors.Err
// code int
// }
//
// func NewFooError(code int) error {
// err := &FooError{errors.NewErr("foo"), code}
// err.SetLocation(1)
// return err
// }
func NewErr(format string, args ...interface{}) Err {
return Err{
message: fmt.Sprintf(format, args...),
}
}
// Location is the file and line of where the error was most recently
// created or annotated.
func (e *Err) Location() (filename string, line int) {
return e.file, e.line
}
// Underlying returns the previous error in the error stack, if any. A client
// should not ever really call this method. It is used to build the error
// stack and should not be introspected by client calls. Or more
// specifically, clients should not depend on anything but the `Cause` of an
// error.
func (e *Err) Underlying() error {
return e.previous
}
// The Cause of an error is the most recent error in the error stack that
// meets one of these criteria: the original error that was raised; the new
// error that was passed into the Wrap function; the most recently masked
// error; or nil if the error itself is considered the Cause. Normally this
// method is not invoked directly, but instead through the Cause stand alone
// function.
func (e *Err) Cause() error {
return e.cause
}
// Message returns the message stored with the most recent location. This is
// the empty string if the most recent call was Trace, or the message stored
// with Annotate or Mask.
func (e *Err) Message() string {
return e.message
}
// Error implements error.Error.
func (e *Err) Error() string {
// We want to walk up the stack of errors showing the annotations
// as long as the cause is the same.
err := e.previous
if !sameError(Cause(err), e.cause) && e.cause != nil {
err = e.cause
}
switch {
case err == nil:
return e.message
case e.message == "":
return err.Error()
}
return fmt.Sprintf("%s: %v", e.message, err)
}
// SetLocation records the source location of the error at callDepth stack
// frames above the call.
func (e *Err) SetLocation(callDepth int) {
_, file, line, _ := runtime.Caller(callDepth + 1)
e.file = trimGoPath(file)
e.line = line
}
// StackTrace returns one string for each location recorded in the stack of
// errors. The first value is the originating error, with a line for each
// other annotation or tracing of the error.
func (e *Err) StackTrace() []string {
return errorStack(e)
}
// Ideally we'd have a way to check identity, but deep equals will do.
func sameError(e1, e2 error) bool {
return reflect.DeepEqual(e1, e2)
}

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@ -1,161 +0,0 @@
// Copyright 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors_test
import (
"fmt"
"runtime"
jc "github.com/juju/testing/checkers"
gc "gopkg.in/check.v1"
"github.com/juju/errors"
)
type errorsSuite struct{}
var _ = gc.Suite(&errorsSuite{})
var someErr = errors.New("some error") //err varSomeErr
func (*errorsSuite) TestErrorString(c *gc.C) {
for i, test := range []struct {
message string
generator func() error
expected string
}{
{
message: "uncomparable errors",
generator: func() error {
err := errors.Annotatef(newNonComparableError("uncomparable"), "annotation")
return errors.Annotatef(err, "another")
},
expected: "another: annotation: uncomparable",
}, {
message: "Errorf",
generator: func() error {
return errors.Errorf("first error")
},
expected: "first error",
}, {
message: "annotated error",
generator: func() error {
err := errors.Errorf("first error")
return errors.Annotatef(err, "annotation")
},
expected: "annotation: first error",
}, {
message: "test annotation format",
generator: func() error {
err := errors.Errorf("first %s", "error")
return errors.Annotatef(err, "%s", "annotation")
},
expected: "annotation: first error",
}, {
message: "wrapped error",
generator: func() error {
err := newError("first error")
return errors.Wrap(err, newError("detailed error"))
},
expected: "detailed error",
}, {
message: "wrapped annotated error",
generator: func() error {
err := errors.Errorf("first error")
err = errors.Annotatef(err, "annotated")
return errors.Wrap(err, fmt.Errorf("detailed error"))
},
expected: "detailed error",
}, {
message: "annotated wrapped error",
generator: func() error {
err := errors.Errorf("first error")
err = errors.Wrap(err, fmt.Errorf("detailed error"))
return errors.Annotatef(err, "annotated")
},
expected: "annotated: detailed error",
}, {
message: "traced, and annotated",
generator: func() error {
err := errors.New("first error")
err = errors.Trace(err)
err = errors.Annotate(err, "some context")
err = errors.Trace(err)
err = errors.Annotate(err, "more context")
return errors.Trace(err)
},
expected: "more context: some context: first error",
}, {
message: "traced, and annotated, masked and annotated",
generator: func() error {
err := errors.New("first error")
err = errors.Trace(err)
err = errors.Annotate(err, "some context")
err = errors.Maskf(err, "masked")
err = errors.Annotate(err, "more context")
return errors.Trace(err)
},
expected: "more context: masked: some context: first error",
},
} {
c.Logf("%v: %s", i, test.message)
err := test.generator()
ok := c.Check(err.Error(), gc.Equals, test.expected)
if !ok {
c.Logf("%#v", test.generator())
}
}
}
type embed struct {
errors.Err
}
func newEmbed(format string, args ...interface{}) *embed {
err := &embed{errors.NewErr(format, args...)}
err.SetLocation(1)
return err
}
func (*errorsSuite) TestNewErr(c *gc.C) {
if runtime.Compiler == "gccgo" {
c.Skip("gccgo can't determine the location")
}
err := newEmbed("testing %d", 42) //err embedErr
c.Assert(err.Error(), gc.Equals, "testing 42")
c.Assert(errors.Cause(err), gc.Equals, err)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["embedErr"].String())
}
var _ error = (*embed)(nil)
// This is an uncomparable error type, as it is a struct that supports the
// error interface (as opposed to a pointer type).
type error_ struct {
info string
slice []string
}
// Create a non-comparable error
func newNonComparableError(message string) error {
return error_{info: message}
}
func (e error_) Error() string {
return e.info
}
func newError(message string) error {
return testError{message}
}
// The testError is a value type error for ease of seeing results
// when the test fails.
type testError struct {
message string
}
func (e testError) Error() string {
return e.message
}

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@ -1,235 +0,0 @@
// Copyright 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors
import (
"fmt"
)
// wrap is a helper to construct an *wrapper.
func wrap(err error, format, suffix string, args ...interface{}) Err {
newErr := Err{
message: fmt.Sprintf(format+suffix, args...),
previous: err,
}
newErr.SetLocation(2)
return newErr
}
// notFound represents an error when something has not been found.
type notFound struct {
Err
}
// NotFoundf returns an error which satisfies IsNotFound().
func NotFoundf(format string, args ...interface{}) error {
return &notFound{wrap(nil, format, " not found", args...)}
}
// NewNotFound returns an error which wraps err that satisfies
// IsNotFound().
func NewNotFound(err error, msg string) error {
return &notFound{wrap(err, msg, "")}
}
// IsNotFound reports whether err was created with NotFoundf() or
// NewNotFound().
func IsNotFound(err error) bool {
err = Cause(err)
_, ok := err.(*notFound)
return ok
}
// userNotFound represents an error when an inexistent user is looked up.
type userNotFound struct {
Err
}
// UserNotFoundf returns an error which satisfies IsUserNotFound().
func UserNotFoundf(format string, args ...interface{}) error {
return &userNotFound{wrap(nil, format, " user not found", args...)}
}
// NewUserNotFound returns an error which wraps err and satisfies
// IsUserNotFound().
func NewUserNotFound(err error, msg string) error {
return &userNotFound{wrap(err, msg, "")}
}
// IsUserNotFound reports whether err was created with UserNotFoundf() or
// NewUserNotFound().
func IsUserNotFound(err error) bool {
err = Cause(err)
_, ok := err.(*userNotFound)
return ok
}
// unauthorized represents an error when an operation is unauthorized.
type unauthorized struct {
Err
}
// Unauthorizedf returns an error which satisfies IsUnauthorized().
func Unauthorizedf(format string, args ...interface{}) error {
return &unauthorized{wrap(nil, format, "", args...)}
}
// NewUnauthorized returns an error which wraps err and satisfies
// IsUnauthorized().
func NewUnauthorized(err error, msg string) error {
return &unauthorized{wrap(err, msg, "")}
}
// IsUnauthorized reports whether err was created with Unauthorizedf() or
// NewUnauthorized().
func IsUnauthorized(err error) bool {
err = Cause(err)
_, ok := err.(*unauthorized)
return ok
}
// notImplemented represents an error when something is not
// implemented.
type notImplemented struct {
Err
}
// NotImplementedf returns an error which satisfies IsNotImplemented().
func NotImplementedf(format string, args ...interface{}) error {
return &notImplemented{wrap(nil, format, " not implemented", args...)}
}
// NewNotImplemented returns an error which wraps err and satisfies
// IsNotImplemented().
func NewNotImplemented(err error, msg string) error {
return &notImplemented{wrap(err, msg, "")}
}
// IsNotImplemented reports whether err was created with
// NotImplementedf() or NewNotImplemented().
func IsNotImplemented(err error) bool {
err = Cause(err)
_, ok := err.(*notImplemented)
return ok
}
// alreadyExists represents and error when something already exists.
type alreadyExists struct {
Err
}
// AlreadyExistsf returns an error which satisfies IsAlreadyExists().
func AlreadyExistsf(format string, args ...interface{}) error {
return &alreadyExists{wrap(nil, format, " already exists", args...)}
}
// NewAlreadyExists returns an error which wraps err and satisfies
// IsAlreadyExists().
func NewAlreadyExists(err error, msg string) error {
return &alreadyExists{wrap(err, msg, "")}
}
// IsAlreadyExists reports whether the error was created with
// AlreadyExistsf() or NewAlreadyExists().
func IsAlreadyExists(err error) bool {
err = Cause(err)
_, ok := err.(*alreadyExists)
return ok
}
// notSupported represents an error when something is not supported.
type notSupported struct {
Err
}
// NotSupportedf returns an error which satisfies IsNotSupported().
func NotSupportedf(format string, args ...interface{}) error {
return &notSupported{wrap(nil, format, " not supported", args...)}
}
// NewNotSupported returns an error which wraps err and satisfies
// IsNotSupported().
func NewNotSupported(err error, msg string) error {
return &notSupported{wrap(err, msg, "")}
}
// IsNotSupported reports whether the error was created with
// NotSupportedf() or NewNotSupported().
func IsNotSupported(err error) bool {
err = Cause(err)
_, ok := err.(*notSupported)
return ok
}
// notValid represents an error when something is not valid.
type notValid struct {
Err
}
// NotValidf returns an error which satisfies IsNotValid().
func NotValidf(format string, args ...interface{}) error {
return &notValid{wrap(nil, format, " not valid", args...)}
}
// NewNotValid returns an error which wraps err and satisfies IsNotValid().
func NewNotValid(err error, msg string) error {
return &notValid{wrap(err, msg, "")}
}
// IsNotValid reports whether the error was created with NotValidf() or
// NewNotValid().
func IsNotValid(err error) bool {
err = Cause(err)
_, ok := err.(*notValid)
return ok
}
// notProvisioned represents an error when something is not yet provisioned.
type notProvisioned struct {
Err
}
// NotProvisionedf returns an error which satisfies IsNotProvisioned().
func NotProvisionedf(format string, args ...interface{}) error {
return &notProvisioned{wrap(nil, format, " not provisioned", args...)}
}
// NewNotProvisioned returns an error which wraps err that satisfies
// IsNotProvisioned().
func NewNotProvisioned(err error, msg string) error {
return &notProvisioned{wrap(err, msg, "")}
}
// IsNotProvisioned reports whether err was created with NotProvisionedf() or
// NewNotProvisioned().
func IsNotProvisioned(err error) bool {
err = Cause(err)
_, ok := err.(*notProvisioned)
return ok
}
// notAssigned represents an error when something is not yet assigned to
// something else.
type notAssigned struct {
Err
}
// NotAssignedf returns an error which satisfies IsNotAssigned().
func NotAssignedf(format string, args ...interface{}) error {
return &notAssigned{wrap(nil, format, " not assigned", args...)}
}
// NewNotAssigned returns an error which wraps err that satisfies
// IsNotAssigned().
func NewNotAssigned(err error, msg string) error {
return &notAssigned{wrap(err, msg, "")}
}
// IsNotAssigned reports whether err was created with NotAssignedf() or
// NewNotAssigned().
func IsNotAssigned(err error) bool {
err = Cause(err)
_, ok := err.(*notAssigned)
return ok
}

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@ -1,171 +0,0 @@
// Copyright 2013, 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors_test
import (
stderrors "errors"
"fmt"
"reflect"
"runtime"
"github.com/juju/errors"
jc "github.com/juju/testing/checkers"
gc "gopkg.in/check.v1"
)
// errorInfo holds information about a single error type: a satisfier
// function, wrapping and variable arguments constructors and message
// suffix.
type errorInfo struct {
satisfier func(error) bool
argsConstructor func(string, ...interface{}) error
wrapConstructor func(error, string) error
suffix string
}
// allErrors holds information for all defined errors. When adding new
// errors, add them here as well to include them in tests.
var allErrors = []*errorInfo{
&errorInfo{errors.IsNotFound, errors.NotFoundf, errors.NewNotFound, " not found"},
&errorInfo{errors.IsUserNotFound, errors.UserNotFoundf, errors.NewUserNotFound, " user not found"},
&errorInfo{errors.IsUnauthorized, errors.Unauthorizedf, errors.NewUnauthorized, ""},
&errorInfo{errors.IsNotImplemented, errors.NotImplementedf, errors.NewNotImplemented, " not implemented"},
&errorInfo{errors.IsAlreadyExists, errors.AlreadyExistsf, errors.NewAlreadyExists, " already exists"},
&errorInfo{errors.IsNotSupported, errors.NotSupportedf, errors.NewNotSupported, " not supported"},
&errorInfo{errors.IsNotValid, errors.NotValidf, errors.NewNotValid, " not valid"},
&errorInfo{errors.IsNotProvisioned, errors.NotProvisionedf, errors.NewNotProvisioned, " not provisioned"},
&errorInfo{errors.IsNotAssigned, errors.NotAssignedf, errors.NewNotAssigned, " not assigned"},
}
type errorTypeSuite struct{}
var _ = gc.Suite(&errorTypeSuite{})
func (t *errorInfo) satisfierName() string {
value := reflect.ValueOf(t.satisfier)
f := runtime.FuncForPC(value.Pointer())
return f.Name()
}
func (t *errorInfo) equal(t0 *errorInfo) bool {
if t0 == nil {
return false
}
return t.satisfierName() == t0.satisfierName()
}
type errorTest struct {
err error
message string
errInfo *errorInfo
}
func deferredAnnotatef(err error, format string, args ...interface{}) error {
errors.DeferredAnnotatef(&err, format, args...)
return err
}
func mustSatisfy(c *gc.C, err error, errInfo *errorInfo) {
if errInfo != nil {
msg := fmt.Sprintf("%#v must satisfy %v", err, errInfo.satisfierName())
c.Check(err, jc.Satisfies, errInfo.satisfier, gc.Commentf(msg))
}
}
func mustNotSatisfy(c *gc.C, err error, errInfo *errorInfo) {
if errInfo != nil {
msg := fmt.Sprintf("%#v must not satisfy %v", err, errInfo.satisfierName())
c.Check(err, gc.Not(jc.Satisfies), errInfo.satisfier, gc.Commentf(msg))
}
}
func checkErrorMatches(c *gc.C, err error, message string, errInfo *errorInfo) {
if message == "<nil>" {
c.Check(err, gc.IsNil)
c.Check(errInfo, gc.IsNil)
} else {
c.Check(err, gc.ErrorMatches, message)
}
}
func runErrorTests(c *gc.C, errorTests []errorTest, checkMustSatisfy bool) {
for i, t := range errorTests {
c.Logf("test %d: %T: %v", i, t.err, t.err)
checkErrorMatches(c, t.err, t.message, t.errInfo)
if checkMustSatisfy {
mustSatisfy(c, t.err, t.errInfo)
}
// Check all other satisfiers to make sure none match.
for _, otherErrInfo := range allErrors {
if checkMustSatisfy && otherErrInfo.equal(t.errInfo) {
continue
}
mustNotSatisfy(c, t.err, otherErrInfo)
}
}
}
func (*errorTypeSuite) TestDeferredAnnotatef(c *gc.C) {
// Ensure DeferredAnnotatef annotates the errors.
errorTests := []errorTest{}
for _, errInfo := range allErrors {
errorTests = append(errorTests, []errorTest{{
deferredAnnotatef(nil, "comment"),
"<nil>",
nil,
}, {
deferredAnnotatef(stderrors.New("blast"), "comment"),
"comment: blast",
nil,
}, {
deferredAnnotatef(errInfo.argsConstructor("foo %d", 42), "comment %d", 69),
"comment 69: foo 42" + errInfo.suffix,
errInfo,
}, {
deferredAnnotatef(errInfo.argsConstructor(""), "comment"),
"comment: " + errInfo.suffix,
errInfo,
}, {
deferredAnnotatef(errInfo.wrapConstructor(stderrors.New("pow!"), "woo"), "comment"),
"comment: woo: pow!",
errInfo,
}}...)
}
runErrorTests(c, errorTests, true)
}
func (*errorTypeSuite) TestAllErrors(c *gc.C) {
errorTests := []errorTest{}
for _, errInfo := range allErrors {
errorTests = append(errorTests, []errorTest{{
nil,
"<nil>",
nil,
}, {
errInfo.argsConstructor("foo %d", 42),
"foo 42" + errInfo.suffix,
errInfo,
}, {
errInfo.argsConstructor(""),
errInfo.suffix,
errInfo,
}, {
errInfo.wrapConstructor(stderrors.New("pow!"), "prefix"),
"prefix: pow!",
errInfo,
}, {
errInfo.wrapConstructor(stderrors.New("pow!"), ""),
"pow!",
errInfo,
}, {
errInfo.wrapConstructor(nil, "prefix"),
"prefix",
errInfo,
}}...)
}
runErrorTests(c, errorTests, true)
}

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@ -1,23 +0,0 @@
// Copyright 2013, 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors_test
import (
"fmt"
"github.com/juju/errors"
)
func ExampleTrace() {
var err1 error = fmt.Errorf("something wicked this way comes")
var err2 error = nil
// Tracing a non nil error will return an error
fmt.Println(errors.Trace(err1))
// Tracing nil will return nil
fmt.Println(errors.Trace(err2))
// Output: something wicked this way comes
// <nil>
}

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@ -1,12 +0,0 @@
// Copyright 2013, 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors
// Since variables are declared before the init block, in order to get the goPath
// we need to return it rather than just reference it.
func GoPath() string {
return goPath
}
var TrimGoPath = trimGoPath

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@ -1,330 +0,0 @@
// Copyright 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors
import (
"fmt"
"strings"
)
// New is a drop in replacement for the standard libary errors module that records
// the location that the error is created.
//
// For example:
// return errors.New("validation failed")
//
func New(message string) error {
err := &Err{message: message}
err.SetLocation(1)
return err
}
// Errorf creates a new annotated error and records the location that the
// error is created. This should be a drop in replacement for fmt.Errorf.
//
// For example:
// return errors.Errorf("validation failed: %s", message)
//
func Errorf(format string, args ...interface{}) error {
err := &Err{message: fmt.Sprintf(format, args...)}
err.SetLocation(1)
return err
}
// Trace adds the location of the Trace call to the stack. The Cause of the
// resulting error is the same as the error parameter. If the other error is
// nil, the result will be nil.
//
// For example:
// if err := SomeFunc(); err != nil {
// return errors.Trace(err)
// }
//
func Trace(other error) error {
if other == nil {
return nil
}
err := &Err{previous: other, cause: Cause(other)}
err.SetLocation(1)
return err
}
// Annotate is used to add extra context to an existing error. The location of
// the Annotate call is recorded with the annotations. The file, line and
// function are also recorded.
//
// For example:
// if err := SomeFunc(); err != nil {
// return errors.Annotate(err, "failed to frombulate")
// }
//
func Annotate(other error, message string) error {
if other == nil {
return nil
}
err := &Err{
previous: other,
cause: Cause(other),
message: message,
}
err.SetLocation(1)
return err
}
// Annotatef is used to add extra context to an existing error. The location of
// the Annotate call is recorded with the annotations. The file, line and
// function are also recorded.
//
// For example:
// if err := SomeFunc(); err != nil {
// return errors.Annotatef(err, "failed to frombulate the %s", arg)
// }
//
func Annotatef(other error, format string, args ...interface{}) error {
if other == nil {
return nil
}
err := &Err{
previous: other,
cause: Cause(other),
message: fmt.Sprintf(format, args...),
}
err.SetLocation(1)
return err
}
// DeferredAnnotatef annotates the given error (when it is not nil) with the given
// format string and arguments (like fmt.Sprintf). If *err is nil, DeferredAnnotatef
// does nothing. This method is used in a defer statement in order to annotate any
// resulting error with the same message.
//
// For example:
//
// defer DeferredAnnotatef(&err, "failed to frombulate the %s", arg)
//
func DeferredAnnotatef(err *error, format string, args ...interface{}) {
if *err == nil {
return
}
newErr := &Err{
message: fmt.Sprintf(format, args...),
cause: Cause(*err),
previous: *err,
}
newErr.SetLocation(1)
*err = newErr
}
// Wrap changes the Cause of the error. The location of the Wrap call is also
// stored in the error stack.
//
// For example:
// if err := SomeFunc(); err != nil {
// newErr := &packageError{"more context", private_value}
// return errors.Wrap(err, newErr)
// }
//
func Wrap(other, newDescriptive error) error {
err := &Err{
previous: other,
cause: newDescriptive,
}
err.SetLocation(1)
return err
}
// Wrapf changes the Cause of the error, and adds an annotation. The location
// of the Wrap call is also stored in the error stack.
//
// For example:
// if err := SomeFunc(); err != nil {
// return errors.Wrapf(err, simpleErrorType, "invalid value %q", value)
// }
//
func Wrapf(other, newDescriptive error, format string, args ...interface{}) error {
err := &Err{
message: fmt.Sprintf(format, args...),
previous: other,
cause: newDescriptive,
}
err.SetLocation(1)
return err
}
// Mask masks the given error with the given format string and arguments (like
// fmt.Sprintf), returning a new error that maintains the error stack, but
// hides the underlying error type. The error string still contains the full
// annotations. If you want to hide the annotations, call Wrap.
func Maskf(other error, format string, args ...interface{}) error {
if other == nil {
return nil
}
err := &Err{
message: fmt.Sprintf(format, args...),
previous: other,
}
err.SetLocation(1)
return err
}
// Mask hides the underlying error type, and records the location of the masking.
func Mask(other error) error {
if other == nil {
return nil
}
err := &Err{
previous: other,
}
err.SetLocation(1)
return err
}
// Cause returns the cause of the given error. This will be either the
// original error, or the result of a Wrap or Mask call.
//
// Cause is the usual way to diagnose errors that may have been wrapped by
// the other errors functions.
func Cause(err error) error {
var diag error
if err, ok := err.(causer); ok {
diag = err.Cause()
}
if diag != nil {
return diag
}
return err
}
type causer interface {
Cause() error
}
type wrapper interface {
// Message returns the top level error message,
// not including the message from the Previous
// error.
Message() string
// Underlying returns the Previous error, or nil
// if there is none.
Underlying() error
}
type locationer interface {
Location() (string, int)
}
var (
_ wrapper = (*Err)(nil)
_ locationer = (*Err)(nil)
_ causer = (*Err)(nil)
)
// Details returns information about the stack of errors wrapped by err, in
// the format:
//
// [{filename:99: error one} {otherfile:55: cause of error one}]
//
// This is a terse alternative to ErrorStack as it returns a single line.
func Details(err error) string {
if err == nil {
return "[]"
}
var s []byte
s = append(s, '[')
for {
s = append(s, '{')
if err, ok := err.(locationer); ok {
file, line := err.Location()
if file != "" {
s = append(s, fmt.Sprintf("%s:%d", file, line)...)
s = append(s, ": "...)
}
}
if cerr, ok := err.(wrapper); ok {
s = append(s, cerr.Message()...)
err = cerr.Underlying()
} else {
s = append(s, err.Error()...)
err = nil
}
s = append(s, '}')
if err == nil {
break
}
s = append(s, ' ')
}
s = append(s, ']')
return string(s)
}
// ErrorStack returns a string representation of the annotated error. If the
// error passed as the parameter is not an annotated error, the result is
// simply the result of the Error() method on that error.
//
// If the error is an annotated error, a multi-line string is returned where
// each line represents one entry in the annotation stack. The full filename
// from the call stack is used in the output.
//
// first error
// github.com/juju/errors/annotation_test.go:193:
// github.com/juju/errors/annotation_test.go:194: annotation
// github.com/juju/errors/annotation_test.go:195:
// github.com/juju/errors/annotation_test.go:196: more context
// github.com/juju/errors/annotation_test.go:197:
func ErrorStack(err error) string {
return strings.Join(errorStack(err), "\n")
}
func errorStack(err error) []string {
if err == nil {
return nil
}
// We want the first error first
var lines []string
for {
var buff []byte
if err, ok := err.(locationer); ok {
file, line := err.Location()
// Strip off the leading GOPATH/src path elements.
file = trimGoPath(file)
if file != "" {
buff = append(buff, fmt.Sprintf("%s:%d", file, line)...)
buff = append(buff, ": "...)
}
}
if cerr, ok := err.(wrapper); ok {
message := cerr.Message()
buff = append(buff, message...)
// If there is a cause for this error, and it is different to the cause
// of the underlying error, then output the error string in the stack trace.
var cause error
if err1, ok := err.(causer); ok {
cause = err1.Cause()
}
err = cerr.Underlying()
if cause != nil && !sameError(Cause(err), cause) {
if message != "" {
buff = append(buff, ": "...)
}
buff = append(buff, cause.Error()...)
}
} else {
buff = append(buff, err.Error()...)
err = nil
}
lines = append(lines, string(buff))
if err == nil {
break
}
}
// reverse the lines to get the original error, which was at the end of
// the list, back to the start.
var result []string
for i := len(lines); i > 0; i-- {
result = append(result, lines[i-1])
}
return result
}

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@ -1,305 +0,0 @@
// Copyright 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors_test
import (
"fmt"
"os"
"path/filepath"
"runtime"
"strings"
jc "github.com/juju/testing/checkers"
gc "gopkg.in/check.v1"
"github.com/juju/errors"
)
type functionSuite struct {
}
var _ = gc.Suite(&functionSuite{})
func (*functionSuite) TestNew(c *gc.C) {
err := errors.New("testing") //err newTest
c.Assert(err.Error(), gc.Equals, "testing")
c.Assert(errors.Cause(err), gc.Equals, err)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["newTest"].String())
}
func (*functionSuite) TestErrorf(c *gc.C) {
err := errors.Errorf("testing %d", 42) //err errorfTest
c.Assert(err.Error(), gc.Equals, "testing 42")
c.Assert(errors.Cause(err), gc.Equals, err)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["errorfTest"].String())
}
func (*functionSuite) TestTrace(c *gc.C) {
first := errors.New("first")
err := errors.Trace(first) //err traceTest
c.Assert(err.Error(), gc.Equals, "first")
c.Assert(errors.Cause(err), gc.Equals, first)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["traceTest"].String())
c.Assert(errors.Trace(nil), gc.IsNil)
}
func (*functionSuite) TestAnnotate(c *gc.C) {
first := errors.New("first")
err := errors.Annotate(first, "annotation") //err annotateTest
c.Assert(err.Error(), gc.Equals, "annotation: first")
c.Assert(errors.Cause(err), gc.Equals, first)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["annotateTest"].String())
c.Assert(errors.Annotate(nil, "annotate"), gc.IsNil)
}
func (*functionSuite) TestAnnotatef(c *gc.C) {
first := errors.New("first")
err := errors.Annotatef(first, "annotation %d", 2) //err annotatefTest
c.Assert(err.Error(), gc.Equals, "annotation 2: first")
c.Assert(errors.Cause(err), gc.Equals, first)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["annotatefTest"].String())
c.Assert(errors.Annotatef(nil, "annotate"), gc.IsNil)
}
func (*functionSuite) TestDeferredAnnotatef(c *gc.C) {
// NOTE: this test fails with gccgo
if runtime.Compiler == "gccgo" {
c.Skip("gccgo can't determine the location")
}
first := errors.New("first")
test := func() (err error) {
defer errors.DeferredAnnotatef(&err, "deferred %s", "annotate")
return first
} //err deferredAnnotate
err := test()
c.Assert(err.Error(), gc.Equals, "deferred annotate: first")
c.Assert(errors.Cause(err), gc.Equals, first)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["deferredAnnotate"].String())
err = nil
errors.DeferredAnnotatef(&err, "deferred %s", "annotate")
c.Assert(err, gc.IsNil)
}
func (*functionSuite) TestWrap(c *gc.C) {
first := errors.New("first") //err wrapFirst
detailed := errors.New("detailed")
err := errors.Wrap(first, detailed) //err wrapTest
c.Assert(err.Error(), gc.Equals, "detailed")
c.Assert(errors.Cause(err), gc.Equals, detailed)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["wrapFirst"].String())
c.Assert(errors.Details(err), jc.Contains, tagToLocation["wrapTest"].String())
}
func (*functionSuite) TestWrapOfNil(c *gc.C) {
detailed := errors.New("detailed")
err := errors.Wrap(nil, detailed) //err nilWrapTest
c.Assert(err.Error(), gc.Equals, "detailed")
c.Assert(errors.Cause(err), gc.Equals, detailed)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["nilWrapTest"].String())
}
func (*functionSuite) TestWrapf(c *gc.C) {
first := errors.New("first") //err wrapfFirst
detailed := errors.New("detailed")
err := errors.Wrapf(first, detailed, "value %d", 42) //err wrapfTest
c.Assert(err.Error(), gc.Equals, "value 42: detailed")
c.Assert(errors.Cause(err), gc.Equals, detailed)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["wrapfFirst"].String())
c.Assert(errors.Details(err), jc.Contains, tagToLocation["wrapfTest"].String())
}
func (*functionSuite) TestWrapfOfNil(c *gc.C) {
detailed := errors.New("detailed")
err := errors.Wrapf(nil, detailed, "value %d", 42) //err nilWrapfTest
c.Assert(err.Error(), gc.Equals, "value 42: detailed")
c.Assert(errors.Cause(err), gc.Equals, detailed)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["nilWrapfTest"].String())
}
func (*functionSuite) TestMask(c *gc.C) {
first := errors.New("first")
err := errors.Mask(first) //err maskTest
c.Assert(err.Error(), gc.Equals, "first")
c.Assert(errors.Cause(err), gc.Equals, err)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["maskTest"].String())
c.Assert(errors.Mask(nil), gc.IsNil)
}
func (*functionSuite) TestMaskf(c *gc.C) {
first := errors.New("first")
err := errors.Maskf(first, "masked %d", 42) //err maskfTest
c.Assert(err.Error(), gc.Equals, "masked 42: first")
c.Assert(errors.Cause(err), gc.Equals, err)
c.Assert(errors.Details(err), jc.Contains, tagToLocation["maskfTest"].String())
c.Assert(errors.Maskf(nil, "mask"), gc.IsNil)
}
func (*functionSuite) TestCause(c *gc.C) {
c.Assert(errors.Cause(nil), gc.IsNil)
c.Assert(errors.Cause(someErr), gc.Equals, someErr)
fmtErr := fmt.Errorf("simple")
c.Assert(errors.Cause(fmtErr), gc.Equals, fmtErr)
err := errors.Wrap(someErr, fmtErr)
c.Assert(errors.Cause(err), gc.Equals, fmtErr)
err = errors.Annotate(err, "annotated")
c.Assert(errors.Cause(err), gc.Equals, fmtErr)
err = errors.Maskf(err, "maksed")
c.Assert(errors.Cause(err), gc.Equals, err)
// Look for a file that we know isn't there.
dir := c.MkDir()
_, err = os.Stat(filepath.Join(dir, "not-there"))
c.Assert(os.IsNotExist(err), jc.IsTrue)
err = errors.Annotatef(err, "wrap it")
// Now the error itself isn't a 'IsNotExist'.
c.Assert(os.IsNotExist(err), jc.IsFalse)
// However if we use the Check method, it is.
c.Assert(os.IsNotExist(errors.Cause(err)), jc.IsTrue)
}
func (s *functionSuite) TestDetails(c *gc.C) {
if runtime.Compiler == "gccgo" {
c.Skip("gccgo can't determine the location")
}
c.Assert(errors.Details(nil), gc.Equals, "[]")
otherErr := fmt.Errorf("other")
checkDetails(c, otherErr, "[{other}]")
err0 := newEmbed("foo") //err TestStack#0
checkDetails(c, err0, "[{$TestStack#0$: foo}]")
err1 := errors.Annotate(err0, "bar") //err TestStack#1
checkDetails(c, err1, "[{$TestStack#1$: bar} {$TestStack#0$: foo}]")
err2 := errors.Trace(err1) //err TestStack#2
checkDetails(c, err2, "[{$TestStack#2$: } {$TestStack#1$: bar} {$TestStack#0$: foo}]")
}
type tracer interface {
StackTrace() []string
}
func (*functionSuite) TestErrorStack(c *gc.C) {
for i, test := range []struct {
message string
generator func() error
expected string
tracer bool
}{
{
message: "nil",
generator: func() error {
return nil
},
}, {
message: "raw error",
generator: func() error {
return fmt.Errorf("raw")
},
expected: "raw",
}, {
message: "single error stack",
generator: func() error {
return errors.New("first error") //err single
},
expected: "$single$: first error",
tracer: true,
}, {
message: "annotated error",
generator: func() error {
err := errors.New("first error") //err annotated-0
return errors.Annotate(err, "annotation") //err annotated-1
},
expected: "" +
"$annotated-0$: first error\n" +
"$annotated-1$: annotation",
tracer: true,
}, {
message: "wrapped error",
generator: func() error {
err := errors.New("first error") //err wrapped-0
return errors.Wrap(err, newError("detailed error")) //err wrapped-1
},
expected: "" +
"$wrapped-0$: first error\n" +
"$wrapped-1$: detailed error",
tracer: true,
}, {
message: "annotated wrapped error",
generator: func() error {
err := errors.Errorf("first error") //err ann-wrap-0
err = errors.Wrap(err, fmt.Errorf("detailed error")) //err ann-wrap-1
return errors.Annotatef(err, "annotated") //err ann-wrap-2
},
expected: "" +
"$ann-wrap-0$: first error\n" +
"$ann-wrap-1$: detailed error\n" +
"$ann-wrap-2$: annotated",
tracer: true,
}, {
message: "traced, and annotated",
generator: func() error {
err := errors.New("first error") //err stack-0
err = errors.Trace(err) //err stack-1
err = errors.Annotate(err, "some context") //err stack-2
err = errors.Trace(err) //err stack-3
err = errors.Annotate(err, "more context") //err stack-4
return errors.Trace(err) //err stack-5
},
expected: "" +
"$stack-0$: first error\n" +
"$stack-1$: \n" +
"$stack-2$: some context\n" +
"$stack-3$: \n" +
"$stack-4$: more context\n" +
"$stack-5$: ",
tracer: true,
}, {
message: "uncomparable, wrapped with a value error",
generator: func() error {
err := newNonComparableError("first error") //err mixed-0
err = errors.Trace(err) //err mixed-1
err = errors.Wrap(err, newError("value error")) //err mixed-2
err = errors.Maskf(err, "masked") //err mixed-3
err = errors.Annotate(err, "more context") //err mixed-4
return errors.Trace(err) //err mixed-5
},
expected: "" +
"first error\n" +
"$mixed-1$: \n" +
"$mixed-2$: value error\n" +
"$mixed-3$: masked\n" +
"$mixed-4$: more context\n" +
"$mixed-5$: ",
tracer: true,
},
} {
c.Logf("%v: %s", i, test.message)
err := test.generator()
expected := replaceLocations(test.expected)
stack := errors.ErrorStack(err)
ok := c.Check(stack, gc.Equals, expected)
if !ok {
c.Logf("%#v", err)
}
tracer, ok := err.(tracer)
c.Check(ok, gc.Equals, test.tracer)
if ok {
stackTrace := tracer.StackTrace()
c.Check(stackTrace, gc.DeepEquals, strings.Split(stack, "\n"))
}
}
}

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@ -1,95 +0,0 @@
// Copyright 2013, 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors_test
import (
"fmt"
"io/ioutil"
"strings"
"testing"
gc "gopkg.in/check.v1"
"github.com/juju/errors"
)
func Test(t *testing.T) {
gc.TestingT(t)
}
func checkDetails(c *gc.C, err error, details string) {
c.Assert(err, gc.NotNil)
expectedDetails := replaceLocations(details)
c.Assert(errors.Details(err), gc.Equals, expectedDetails)
}
func checkErr(c *gc.C, err, cause error, msg string, details string) {
c.Assert(err, gc.NotNil)
c.Assert(err.Error(), gc.Equals, msg)
c.Assert(errors.Cause(err), gc.Equals, cause)
expectedDetails := replaceLocations(details)
c.Assert(errors.Details(err), gc.Equals, expectedDetails)
}
func replaceLocations(line string) string {
result := ""
for {
i := strings.Index(line, "$")
if i == -1 {
break
}
result += line[0:i]
line = line[i+1:]
i = strings.Index(line, "$")
if i == -1 {
panic("no second $")
}
result += location(line[0:i]).String()
line = line[i+1:]
}
result += line
return result
}
func location(tag string) Location {
loc, ok := tagToLocation[tag]
if !ok {
panic(fmt.Sprintf("tag %q not found", tag))
}
return loc
}
type Location struct {
file string
line int
}
func (loc Location) String() string {
return fmt.Sprintf("%s:%d", loc.file, loc.line)
}
var tagToLocation = make(map[string]Location)
func setLocationsForErrorTags(filename string) {
data, err := ioutil.ReadFile(filename)
if err != nil {
panic(err)
}
filename = "github.com/juju/errors/" + filename
lines := strings.Split(string(data), "\n")
for i, line := range lines {
if j := strings.Index(line, "//err "); j >= 0 {
tag := line[j+len("//err "):]
if _, found := tagToLocation[tag]; found {
panic(fmt.Sprintf("tag %q already processed previously", tag))
}
tagToLocation[tag] = Location{file: filename, line: i + 1}
}
}
}
func init() {
setLocationsForErrorTags("error_test.go")
setLocationsForErrorTags("functions_test.go")
}

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@ -1,35 +0,0 @@
// Copyright 2013, 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors
import (
"runtime"
"strings"
)
// prefixSize is used internally to trim the user specific path from the
// front of the returned filenames from the runtime call stack.
var prefixSize int
// goPath is the deduced path based on the location of this file as compiled.
var goPath string
func init() {
_, file, _, ok := runtime.Caller(0)
if ok {
// We know that the end of the file should be:
// github.com/juju/errors/path.go
size := len(file)
suffix := len("github.com/juju/errors/path.go")
goPath = file[:size-suffix]
prefixSize = len(goPath)
}
}
func trimGoPath(filename string) string {
if strings.HasPrefix(filename, goPath) {
return filename[prefixSize:]
}
return filename
}

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@ -1,29 +0,0 @@
// Copyright 2013, 2014 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package errors_test
import (
"path"
gc "gopkg.in/check.v1"
"github.com/juju/errors"
)
type pathSuite struct{}
var _ = gc.Suite(&pathSuite{})
func (*pathSuite) TestGoPathSet(c *gc.C) {
c.Assert(errors.GoPath(), gc.Not(gc.Equals), "")
}
func (*pathSuite) TestTrimGoPath(c *gc.C) {
relativeImport := "github.com/foo/bar/baz.go"
filename := path.Join(errors.GoPath(), relativeImport)
c.Assert(errors.TrimGoPath(filename), gc.Equals, relativeImport)
absoluteImport := "/usr/share/foo/bar/baz.go"
c.Assert(errors.TrimGoPath(absoluteImport), gc.Equals, absoluteImport)
}