Add sentinel errors for slice operations

Author: milldr

pkg/utils/slice_utils.go

@@ -1,10 +1,15 @@
 package utils
 
 import (
+	"errors"
 	"fmt"
 	"strings"
+)
 
-	"github.com/pkg/errors"
+// Package-level sentinel errors for slice operations
+var (
+	ErrNilInput         = errors.New("input must not be nil")
+	ErrNonStringElement = errors.New("element is not a string")
 )
 
 // SliceContainsString checks if a string is present in a slice
@@ -68,14 +73,14 @@ func SliceOfInterfacesToSliceOfStrings(input []any) []string {
 // This function returns an error if any element is not a string.
 func SliceOfInterfacesToSliceOfStringsWithTypeAssertion(input []any) ([]string, error) {
 	if input == nil {
-		return nil, errors.New("input must not be nil")
+		return nil, ErrNilInput
 	}
 
 	output := make([]string, len(input))
 	for i, current := range input {
 		s, ok := current.(string)
 		if !ok {
-			return nil, errors.New(fmt.Sprintf("element at index %d is not a string, got %T", i, current))
+			return nil, fmt.Errorf("%w: index=%d, got=%T", ErrNonStringElement, i, current)
 		}
 		output[i] = s
 	}