xerrors

README

xerrors

• 错误栈
• 可扩展
  • 可以附加错误码
  • 可以附加用户文案
  • 可以附加具体错误详情
• WithMessage "aa" not found
• WithStack
• Wrap
• Is
• Cause Unwrap
• As
• 序列化和反序列化
• NewWithContext 记录错误ID
• FormatError 调试模式，
• 错误链
• Named 命名空间
• 错误码
• 用户文案，最好是在逻辑层（service logic）增加。（流程）
• 三类错误
  • 上游系统错误
  • 本系统错误（包含系统以来的数据库等本服务资源）
  • 下游系统错误（下游业务系统）
• 尽量避免 sentinel 错误，应当立即处理。
  • 例如 gorm.ErrNotFound 可以通过指针判空或者数组长度判零，或者通过显示的返回

TODO

https://go.googlesource.com/proposal/+/master/design/go2draft.md https://github.com/golang/exp/tree/master/errors import "golang.org/x/xerrors"

有个问题
处理错误的时候，不清楚错误是带栈的还是不带栈的
一种方法是，所有返回错误的地方都 Wrap 一下
另一种方法是，代码分层比较好。这样也可以区分

还有个问题
就是错误码的问题。
这个包，没有考虑错误码。
这个也需要自己额外关注。但是错误码，只是协议层(go-kit Transport层，序列化和反序列化错误时需要的)需要的东西。

还有个问题
就是区分内部错误和外部错误。
内部错误，可能直接占用一个码，不需要对外告诉具体细节（生产环境）
外部错误，需要把错误信息，返回给调用方。

产生错误的时候，不一定知道是内部错误，还是外部错误
// 产生错误的时候，只表明是什么错误（是什么类型的错误），而不表明是内部错误还是外部错误

Documentation

Index

• func As(err error, target interface{}) bool
• func Is(err, target error) bool
• func Opaque(err error) error
• func Unwrap(err error) error
• type Frame
  • func (f Frame) Format(s fmt.State, verb rune)
• type StackTrace
  • func (st StackTrace) Format(s fmt.State, verb rune)
• type Wrapper

Functions

func As

func As(err error, target interface{}) bool

As finds the first error in err's chain that matches the type to which target points, and if so, sets the target to its value and returns true. An error matches a type if it is assignable to the target type, or if it has a method As(interface{}) bool such that As(target) returns true. As will panic if target is not a non-nil pointer to a type which implements error or is of interface type.

The As method should set the target to its value and return true if err matches the type to which target points.

func Is

func Is(err, target error) bool

Is reports whether any error in err's chain matches target.

An error is considered to match a target if it is equal to that target or if it implements a method Is(error) bool such that Is(target) returns true.

func Opaque

func Opaque(err error) error

Opaque returns an error with the same error formatting as err but that does not match err and cannot be unwrapped.

func Unwrap

func Unwrap(err error) error

Unwrap returns the result of calling the Unwrap method on err, if err implements Unwrap. Otherwise, Unwrap returns nil.

Types

type Frame

type Frame uintptr

Frame represents a program counter inside a stack frame.

func (Frame) Format

func (f Frame) Format(s fmt.State, verb rune)

Format formats the frame according to the fmt.Formatter interface.

%s    source file
%d    source line
%n    function name
%v    equivalent to %s:%d

Format accepts flags that alter the printing of some verbs, as follows:

%+s   function name and path of source file relative to the compile time
      GOPATH separated by \n\t (<funcname>\n\t<path>)
%+v   equivalent to %+s:%d

type StackTrace

type StackTrace []Frame

StackTrace is stack of Frames from innermost (newest) to outermost (oldest).

func (StackTrace) Format

func (st StackTrace) Format(s fmt.State, verb rune)

Format formats the stack of Frames according to the fmt.Formatter interface.

%s	lists source files for each Frame in the stack
%v	lists the source file and line number for each Frame in the stack

Format accepts flags that alter the printing of some verbs, as follows:

%+v   Prints filename, function, and line number for each Frame in the stack.

type Wrapper

type Wrapper interface {
	// Unwrap returns the next error in the error chain.
	// If there is no next error, Unwrap returns nil.
	Unwrap() error
}

A Wrapper provides context around another error.