add At function

exception.go

@@ -4,11 +4,13 @@ import (
 	"bytes"
 	"fmt"
 	"os"
+	"reflect"
 	"strings"
 )
 
 type Custom interface {
 	error
+	At(source any) Custom
 	With(innerErr ...error) Custom
 	IsSameAs(err error) bool
 }
@@ -30,6 +32,13 @@ func (ex *custom) With(innerErr ...error) Custom {
 	return ex
 }
 
+func (ex *custom) At(source any) Custom {
+	if source != nil {
+		ex.message = fmt.Sprintf("%s in %s", ex.message, getType(source))
+	}
+	return ex
+}
+
 func (ex *custom) IsSameAs(err error) bool {
 	if err == nil {
 		return false
@@ -54,3 +63,14 @@ func getOsNewLine() string {
 	}
 	return "\r\n"
 }
+
+func getType[T any](source T) string {
+	typeName := ""
+	typeOf := reflect.TypeOf(source)
+	if typeOf != nil {
+		typeName = typeOf.String()
+	} else {
+		typeName = reflect.TypeOf((*T)(nil)).Elem().String()
+	}
+	return typeName
+}

exception_test.go

@@ -32,9 +32,9 @@ func (suite *CustomExceptionTestSuite) TestShouldAddInnerErrors() {
 
 func (suite *CustomExceptionTestSuite) TestShouldAddInnerErrorsAfterCreation() {
 	ex := exception.NewCustom("fail")
-	ex.With(fmt.Errorf("innerError1"), fmt.Errorf("innerError2"))
+	ex.At(suite).With(fmt.Errorf("innerError1"), fmt.Errorf("innerError2"))
 	suite.NotNil(ex)
-	suite.Equal(ex.Error(), "[fail]:\ninnerError1\ninnerError2")
+	suite.Equal(ex.Error(), "[fail in *exception_test.CustomExceptionTestSuite]:\ninnerError1\ninnerError2")
 }
 
 func (suite *CustomExceptionTestSuite) TestShouldCompareExceptions() {