cm fix error wraping & unwrapping of stderrors (#22)

Author: Dean Karn

CHANGELOG.md

@@ -6,6 +6,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [5.3.3] - 2023-08-16
+### Fixed
+- First error inconsistently wrapped with error and prefix instead of err then prefix in the chain.
+- Corrected Is & As functions to directly causal error.
+
 ## [5.3.2] - 2023-08-16
 ### Fixed
 - Link Error output missing error when prefix was blank.
@@ -41,7 +46,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Updated deps.
 
 
-[Unreleased]: https://github.com/go-playground/errors/compare/v5.3.2...HEAD
+[Unreleased]: https://github.com/go-playground/errors/compare/v5.3.3...HEAD
+[5.3.3]: https://github.com/go-playground/errors/compare/v5.3.2...v5.3.3
 [5.3.2]: https://github.com/go-playground/errors/compare/v5.3.1...v5.3.2
 [5.3.1]: https://github.com/go-playground/errors/compare/v5.3.0...v5.3.1
 [5.3.0]: https://github.com/go-playground/errors/compare/v5.2.3...v5.3.0

README.md

@@ -1,6 +1,6 @@
 Package errors
 ============
-![Project status](https://img.shields.io/badge/version-5.3.2-green.svg)
+![Project status](https://img.shields.io/badge/version-5.3.3-green.svg)
 [![Build Status](https://travis-ci.org/go-playground/errors.svg?branch=master)](https://travis-ci.org/go-playground/errors)
 [![Go Report Card](https://goreportcard.com/badge/github.com/go-playground/errors)](https://goreportcard.com/report/github.com/go-playground/errors)
 [![GoDoc](https://godoc.org/github.com/go-playground/errors?status.svg)](https://pkg.go.dev/github.com/go-playground/errors/v5)

chain.go

@@ -34,7 +34,6 @@ func newLink(err error, prefix string, skipFrames int) *Link {
 		Prefix: prefix,
 		Source: runtimeext.StackLevel(skipFrames),
 	}
-
 }
 
 // Chain contains the chained errors, the links, of the chains if you will
@@ -214,7 +213,16 @@ func (c Chain) Unwrap() error {
 
 // Is reports whether any error in error chain matches target.
 func (c Chain) Is(target error) bool {
-	return stderrors.Is(c[len(c)-1].Err, target)
+	if len(c) == 0 {
+		return false
+	}
+	if innerErr, ok := target.(Chain); ok {
+		if len(innerErr) == 0 {
+			return false
+		}
+		target = innerErr[0].Err
+	}
+	return stderrors.Is(c[0].Err, target)
 }
 
 // As finds the first error in the error chain that matches target, and if so, sets
@@ -234,7 +242,10 @@ func (c Chain) Is(target error) bool {
 // As panics if target is not a non-nil pointer to either a type that implements
 // error, or to any interface type.
 func (c Chain) As(target any) bool {
-	return stderrors.As(c[len(c)-1].Err, target)
+	if len(c) == 0 {
+		return false
+	}
+	return stderrors.As(c[0].Err, target)
 }
 
 func defaultFormatFn(c Chain) string {

errors.go

@@ -1,7 +1,6 @@
 package errors
 
 import (
-	"errors"
 	stderrors "errors"
 	"fmt"
 	"reflect"
@@ -38,7 +37,7 @@ func RegisterErrorFormatFn(fn ErrorFormatFn) {
 
 // New creates an error with the provided text and automatically wraps it with line information.
 func New(s string) Chain {
-	return wrap(errors.New(s), "", 3)
+	return wrap(stderrors.New(s), "", 3)
 }
 
 // Newf creates an error with the provided text and automatically wraps it with line information.
@@ -74,12 +73,15 @@ func wrap(err error, prefix string, skipFrames int) (c Chain) {
 	if c, ok = err.(Chain); ok {
 		c = append(c, newLink(nil, prefix, skipFrames))
 	} else {
-		c = Chain{newLink(err, prefix, skipFrames)}
+		c = Chain{newLink(err, "", skipFrames)}
 		for _, h := range helpers {
 			if !h(c, err) {
 				break
 			}
 		}
+		if prefix != "" {
+			c = append(c, &Link{Prefix: prefix, Source: c[0].Source})
+		}
 	}
 	return
 }