Xerror

Package xerror implements helpers for errors.

Source:

https://github.com/duke-git/lancet/blob/main/xerror/xerror.go

Usage:

import (
    "github.com/duke-git/lancet/v2/xerror"
)

import (
    "github.com/duke-git/lancet/v2/xerror"
)

Index

New
Wrap
Unwrap
XError_Wrap
XError_Unwrap
XError_With
XError_Is
XError_Id
XError_Values
XError_StackTrace
XError_Info
XError_Error
TryUnwrap

Documentation

New

Creates a new XError pointer instance with message.

Signature:

type XError struct {
    id      string
    message string
    stack   *stack
    cause   error
    values  map[string]any
}

func New(format string, args ...any) *XError

type XError struct {
    id      string
    message string
    stack   *stack
    cause   error
    values  map[string]any
}

func New(format string, args ...any) *XError

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error")
    fmt.Println(err.Error())

    // Output:
    // error
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error")
    fmt.Println(err.Error())

    // Output:
    // error
}

Wrap

Creates a new XError pointer instance based on error object, and add message.

Signature:

func Wrap(cause error, message ...any) *XError

func Wrap(cause error, message ...any) *XError

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("wrong password")
    wrapErr := xerror.Wrap(err, "error")

    fmt.Println(wrapErr.Error())

    // Output:
    // error: wrong password
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("wrong password")
    wrapErr := xerror.Wrap(err, "error")

    fmt.Println(wrapErr.Error())

    // Output:
    // error: wrong password
}

Unwrap

Returns unwrapped XError from err by errors.As. If no XError, returns nil.

Signature:

func Unwrap(err error) *XError

func Unwrap(err error) *XError

Example:Run

package main

import (
    "fmt"
    "github.com/pkg/errors"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").With("level", "high")
    wrapErr := errors.Wrap(err1, "oops")

    err := xerror.Unwrap(wrapErr)

    values := err.Values()
    fmt.Println(values["level"])

    // Output:
    // high
}

package main

import (
    "fmt"
    "github.com/pkg/errors"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").With("level", "high")
    wrapErr := errors.Wrap(err1, "oops")

    err := xerror.Unwrap(wrapErr)

    values := err.Values()
    fmt.Println(values["level"])

    // Output:
    // high
}

XError_Wrap

Creates a new XError and copy message and id to new one.

Signature:

func (e *XError) Wrap(cause error) *XError

func (e *XError) Wrap(cause error) *XError

Example:Run

package main

import (
    "fmt"
    "errors"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").With("level", "high")
	err2 := err1.Wrap(errors.New("invalid username"))

	fmt.Println(err2.Error())

	// Output:
	// error: invalid username
}

package main

import (
    "fmt"
    "errors"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").With("level", "high")
	err2 := err1.Wrap(errors.New("invalid username"))

	fmt.Println(err2.Error())

	// Output:
	// error: invalid username
}

XError_Unwrap

Compatible with github.com/pkg/errors.

Signature:

func (e *XError) Unwrap() error

func (e *XError) Unwrap() error

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").With("level", "high")
    err2 := err1.Wrap(errors.New("invalid username"))

    err := err2.Unwrap()

    fmt.Println(err.Error())

    // Output:
    // invalid username
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").With("level", "high")
    err2 := err1.Wrap(errors.New("invalid username"))

    err := err2.Unwrap()

    fmt.Println(err.Error())

    // Output:
    // invalid username
}

XError_With

Adds key and value related to the XError object.

Signature:

func (e *XError) With(key string, value any) *XError

func (e *XError) With(key string, value any) *XError

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error").With("level", "high")

    errLevel := err.Values()["level"]

    fmt.Println(errLevel)

    // Output:
    // high
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error").With("level", "high")

    errLevel := err.Values()["level"]

    fmt.Println(errLevel)

    // Output:
    // high
}

XError_Id

Sets XError object id to check equality in XError.Is.

Signature:

func (e *XError) Id(id string) *XError

func (e *XError) Id(id string) *XError

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").Id("e001")
    err2 := xerror.New("error").Id("e001")
    err3 := xerror.New("error").Id("e003")

    equal := err1.Is(err2)
    notEqual := err1.Is(err3)

    fmt.Println(equal)
    fmt.Println(notEqual)

    // Output:
    // true
    // false
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").Id("e001")
    err2 := xerror.New("error").Id("e001")
    err3 := xerror.New("error").Id("e003")

    equal := err1.Is(err2)
    notEqual := err1.Is(err3)

    fmt.Println(equal)
    fmt.Println(notEqual)

    // Output:
    // true
    // false
}

XError_Is

Checks if target error is XError and Error.id of two errors are matched.

Signature:

func (e *XError) Is(target error) bool

func (e *XError) Is(target error) bool

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").Id("e001")
    err2 := xerror.New("error").Id("e001")
    err3 := xerror.New("error").Id("e003")

    equal := err1.Is(err2)
    notEqual := err1.Is(err3)

    fmt.Println(equal)
    fmt.Println(notEqual)

    // Output:
    // true
    // false
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err1 := xerror.New("error").Id("e001")
    err2 := xerror.New("error").Id("e001")
    err3 := xerror.New("error").Id("e003")

    equal := err1.Is(err2)
    notEqual := err1.Is(err3)

    fmt.Println(equal)
    fmt.Println(notEqual)

    // Output:
    // true
    // false
}

XError_Values

Returns map of key and value that is set by With. All wrapped xerror.XError key and values will be merged. Key and values of wrapped error is overwritten by upper xerror.XError.

Signature:

func (e *XError) Values() map[string]any

func (e *XError) Values() map[string]any

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error").With("level", "high")

    errLevel := err.Values()["level"]

    fmt.Println(errLevel)

    // Output:
    // high
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error").With("level", "high")

    errLevel := err.Values()["level"]

    fmt.Println(errLevel)

    // Output:
    // high
}

XError_StackTrace

Returns stack trace which is compatible with pkg/errors.

Signature:

func (e *XError) StackTrace() StackTrace

func (e *XError) StackTrace() StackTrace

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error")

    stacks := err.Stacks()

    fmt.Println(stacks[0].Func)
    fmt.Println(stacks[0].Line)

    containFile := strings.Contains(stacks[0].File, "xxx.go")
    fmt.Println(containFile)
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error")

    stacks := err.Stacks()

    fmt.Println(stacks[0].Func)
    fmt.Println(stacks[0].Line)

    containFile := strings.Contains(stacks[0].File, "xxx.go")
    fmt.Println(containFile)
}

XError_Info

Returns information of xerror, which can be printed.

Signature:

func (e *XError) Info() *errInfo

func (e *XError) Info() *errInfo

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    cause := errors.New("error")
    err := xerror.Wrap(cause, "invalid username").Id("e001").With("level", "high")

    errInfo := err.Info()

    fmt.Println(errInfo.Id)
    fmt.Println(errInfo.Cause)
    fmt.Println(errInfo.Values["level"])
    fmt.Println(errInfo.Message)

    // Output:
    // e001
    // error
    // high
    // invalid username
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    cause := errors.New("error")
    err := xerror.Wrap(cause, "invalid username").Id("e001").With("level", "high")

    errInfo := err.Info()

    fmt.Println(errInfo.Id)
    fmt.Println(errInfo.Cause)
    fmt.Println(errInfo.Values["level"])
    fmt.Println(errInfo.Message)

    // Output:
    // e001
    // error
    // high
    // invalid username
}

XError_Error

Error implements standard error interface.

Signature:

func (e *XError) Error() string

func (e *XError) Error() string

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error")
    fmt.Println(err.Error())

    // Output:
    // error
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    err := xerror.New("error")
    fmt.Println(err.Error())

    // Output:
    // error
}

TryUnwrap

TryUnwrap if err is nil then it returns a valid value. If err is not nil, Unwrap panics with err.

Signature:

func TryUnwrap[T any](val T, err error) T

func TryUnwrap[T any](val T, err error) T

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    result1 := xerror.TryUnwrap(strconv.Atoi("42"))
    fmt.Println(result1)

    _, err := strconv.Atoi("4o2")
    defer func() {
        v := recover()
        result2 := reflect.DeepEqual(err.Error(), v.(*strconv.NumError).Error())
        fmt.Println(result2)
    }()

    xerror.TryUnwrap(strconv.Atoi("4o2"))

    // Output:
    // 42
    // true
}

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/xerror"
)

func main() {
    result1 := xerror.TryUnwrap(strconv.Atoi("42"))
    fmt.Println(result1)

    _, err := strconv.Atoi("4o2")
    defer func() {
        v := recover()
        result2 := reflect.DeepEqual(err.Error(), v.(*strconv.NumError).Error())
        fmt.Println(result2)
    }()

    xerror.TryUnwrap(strconv.Atoi("4o2"))

    // Output:
    // 42
    // true
}

Xerror ​

Source: ​

Usage: ​

Index ​

Documentation ​

New ​

Wrap ​

Unwrap ​

XError_Wrap ​

XError_Unwrap ​

XError_With ​

XError_Id ​

XError_Is ​

XError_Values ​

XError_StackTrace ​

XError_Info ​

XError_Error ​

TryUnwrap ​

Xerror

Source:

Usage:

Index

Documentation

New

Wrap

Unwrap

XError_Wrap

XError_Unwrap

XError_With

XError_Id

XError_Is

XError_Values

XError_StackTrace

XError_Info

XError_Error

TryUnwrap