From aa33bc8df3895c103c8450f8cc2e1d9ba07c019e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mike=20Schw=C3=B6rer?= <pubgit@mikescher.com>
Date: Tue, 8 Aug 2023 13:09:15 +0200
Subject: [PATCH] v0.0.225

---
 exerr/constructor.go |  3 ++
 exerr/exerr.go       | 25 ++++++++++--
 exerr/exerr_test.go  | 93 ++++++++++++++++++++++++++++++++++++++++++++
 goextVersion.go      |  4 +-
 4 files changed, 119 insertions(+), 6 deletions(-)
 create mode 100644 exerr/exerr_test.go

diff --git a/exerr/constructor.go b/exerr/constructor.go
index 2b66dab..b4444fc 100644
--- a/exerr/constructor.go
+++ b/exerr/constructor.go
@@ -27,6 +27,7 @@ func FromError(err error) *ExErr {
 		StatusCode:     nil,
 		Message:        err.Error(),
 		WrappedErrType: fmt.Sprintf("%T", err),
+		WrappedErr:     err,
 		Caller:         "",
 		OriginalError:  nil,
 		Meta:           getForeignMeta(err),
@@ -43,6 +44,7 @@ func newExErr(cat ErrorCategory, errtype ErrorType, msg string) *ExErr {
 		StatusCode:     nil,
 		Message:        msg,
 		WrappedErrType: "",
+		WrappedErr:     nil,
 		Caller:         callername(2),
 		OriginalError:  nil,
 		Meta:           make(map[string]MetaValue),
@@ -59,6 +61,7 @@ func wrapExErr(e *ExErr, msg string, cat ErrorCategory, stacktraceskip int) *ExE
 		StatusCode:     e.StatusCode,
 		Message:        msg,
 		WrappedErrType: "",
+		WrappedErr:     nil,
 		Caller:         callername(1 + stacktraceskip),
 		OriginalError:  e,
 		Meta:           make(map[string]MetaValue),
diff --git a/exerr/exerr.go b/exerr/exerr.go
index 0471d20..a6dd2e6 100644
--- a/exerr/exerr.go
+++ b/exerr/exerr.go
@@ -4,6 +4,7 @@ import (
 	"github.com/rs/xid"
 	"github.com/rs/zerolog"
 	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"reflect"
 	"strings"
 	"time"
 )
@@ -20,6 +21,7 @@ type ExErr struct {
 
 	Message        string `json:"message"`
 	WrappedErrType string `json:"wrappedErrType"`
+	WrappedErr     any    `json:"-"`
 	Caller         string `json:"caller"`
 
 	OriginalError *ExErr `json:"originalError"`
@@ -33,6 +35,9 @@ func (ee *ExErr) Error() string {
 
 // Unwrap must be implemented so that some error.XXX methods work
 func (ee *ExErr) Unwrap() error {
+	if ee.OriginalError == nil {
+		return nil // this is neccessary - otherwise we return a wrapped nil and the `x == nil` comparison fails (= panic in errors.Is and other failures)
+	}
 	return ee.OriginalError
 }
 
@@ -44,17 +49,29 @@ func (ee *ExErr) Is(e error) bool {
 // As must be implemented so that error.As(x) works
 //
 //goland:noinspection GoTypeAssertionOnErrors
-func (ee *ExErr) As(e any) bool {
-	if dstErr, ok := e.(*ExErr); ok {
+func (ee *ExErr) As(target any) bool {
+	if dstErr, ok := target.(*ExErr); ok {
+
 		if dst0, ok := ee.contains(dstErr); ok {
 			dstErr = dst0
 			return true
 		} else {
 			return false
 		}
-	} else if dstErr, ok := e.(error); ok {
-		return IsFrom(ee, dstErr)
+
 	} else {
+
+		val := reflect.ValueOf(target)
+
+		typStr := val.Type().Elem().String()
+
+		for curr := ee; curr != nil; curr = curr.OriginalError {
+			if curr.Category == CatForeign && curr.WrappedErrType == typStr && curr.WrappedErr != nil {
+				val.Elem().Set(reflect.ValueOf(curr.WrappedErr))
+				return true
+			}
+		}
+
 		return false
 	}
 }
diff --git a/exerr/exerr_test.go b/exerr/exerr_test.go
new file mode 100644
index 0000000..ee98351
--- /dev/null
+++ b/exerr/exerr_test.go
@@ -0,0 +1,93 @@
+package exerr
+
+import (
+	"errors"
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
+	"testing"
+)
+
+type golangErr struct {
+	Message string
+}
+
+func (g golangErr) Error() string {
+	return g.Message
+}
+
+type golangErr2 struct {
+	Message string
+}
+
+func (g golangErr2) Error() string {
+	return g.Message
+}
+
+type simpleError struct {
+}
+
+func (g simpleError) Error() string {
+	return "Something simple went wroong"
+}
+
+type simpleError2 struct {
+}
+
+func (g simpleError2) Error() string {
+	return "Something simple went wroong"
+}
+
+func TestExErrIs1(t *testing.T) {
+	e0 := simpleError{}
+
+	wrap := Wrap(e0, "something went wrong").Str("test", "123").Build()
+
+	tst.AssertTrue(t, errors.Is(wrap, simpleError{}))
+	tst.AssertFalse(t, errors.Is(wrap, golangErr{}))
+	tst.AssertFalse(t, errors.Is(wrap, golangErr{"error1"}))
+}
+
+func TestExErrIs2(t *testing.T) {
+	e0 := golangErr{"error1"}
+
+	wrap := Wrap(e0, "something went wrong").Str("test", "123").Build()
+
+	tst.AssertTrue(t, errors.Is(wrap, e0))
+	tst.AssertTrue(t, errors.Is(wrap, golangErr{"error1"}))
+	tst.AssertFalse(t, errors.Is(wrap, golangErr{"error2"}))
+	tst.AssertFalse(t, errors.Is(wrap, simpleError{}))
+}
+
+func TestExErrAs(t *testing.T) {
+
+	e0 := golangErr{"error1"}
+
+	w0 := Wrap(e0, "something went wrong").Str("test", "123").Build()
+
+	{
+		out := golangErr{}
+		ok := errors.As(w0, &out)
+		tst.AssertTrue(t, ok)
+		tst.AssertEqual(t, out.Message, "error1")
+	}
+
+	w1 := Wrap(w0, "outher error").Build()
+
+	{
+		out := golangErr{}
+		ok := errors.As(w1, &out)
+		tst.AssertTrue(t, ok)
+		tst.AssertEqual(t, out.Message, "error1")
+	}
+
+	{
+		out := golangErr2{}
+		ok := errors.As(w1, &out)
+		tst.AssertFalse(t, ok)
+	}
+
+	{
+		out := simpleError2{}
+		ok := errors.As(w1, &out)
+		tst.AssertFalse(t, ok)
+	}
+}
diff --git a/goextVersion.go b/goextVersion.go
index 988f493..1f5760e 100644
--- a/goextVersion.go
+++ b/goextVersion.go
@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.224"
+const GoextVersion = "0.0.225"
 
-const GoextVersionTimestamp = "2023-08-08T12:38:22+0200"
+const GoextVersionTimestamp = "2023-08-08T13:09:15+0200"