Package xerror implements helpers for errors.
import (
"github.com/duke-git/lancet/v2/xerror"
)
- New
- Wrap
- Unwrap
- XError_Wrap
- XError_Unwrap
- XError_With
- XError_Is
- XError_Id
- XError_Values
- XError_StackTrace
- XError_Info
- XError_Error
- TryUnwrap
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
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
}
Creates a new XError pointer instance based on error object, and add message.
Signature:
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
}
Returns unwrapped XError from err by errors.As. If no XError, returns nil.
Signature:
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
}
Creates a new XError and copy message and id to new one.
Signature:
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
}
Compatible with github.com/pkg/errors.
Signature:
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
}
Adds key and value related to the XError object.
Signature:
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
}
Sets XError object id to check equality in XError.Is.
Signature:
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
}
Checks if target error is XError and Error.id of two errors are matched.
Signature:
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
}
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
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
}
Returns stack trace which is compatible with pkg/errors.
Signature:
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)
}
Returns information of xerror, which can be printed.
Signature:
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
}
Error implements standard error interface.
Signature:
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
}
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
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
}