Add CombineErrors helper function

internal/errors/errors.go

@@ -2,6 +2,7 @@ package errors
 
 import (
 	stderrors "errors"
+	"fmt"
 
 	"github.com/pkg/errors"
 )
@@ -22,12 +23,42 @@ var Wrap = errors.Wrap
 // nil, Wrapf returns nil.
 var Wrapf = errors.Wrapf
 
+// WithStack annotates err with a stack trace at the point WithStack was called.
+// If err is nil, WithStack returns nil.
 var WithStack = errors.WithStack
 
 // Go 1.13-style error handling.
 
+// As finds the first error in err's tree that matches target, and if one is found,
+// sets target to that error value and returns true. Otherwise, it returns false.
 func As(err error, tgt interface{}) bool { return stderrors.As(err, tgt) }
 
+// Is reports whether any error in err's tree matches target.
 func Is(x, y error) bool { return stderrors.Is(x, y) }
 
+// Unwrap returns the result of calling the Unwrap method on err, if err's type contains
+// an Unwrap method returning error. Otherwise, Unwrap returns nil.
+//
+// Unwrap only calls a method of the form "Unwrap() error". In particular Unwrap does not
+// unwrap errors returned by [Join].
 func Unwrap(err error) error { return stderrors.Unwrap(err) }
+
+// CombineErrors combines multiple errors into a single error.
+func CombineErrors(errors ...error) error {
+	var combinedErrorMsg string
+
+	for _, err := range errors {
+		if err != nil {
+			if combinedErrorMsg != "" {
+				combinedErrorMsg += "; " // Separate error messages with a delimiter
+			}
+			combinedErrorMsg += err.Error()
+		}
+	}
+
+	if combinedErrorMsg == "" {
+		return nil // No errors, return nil
+	}
+
+	return fmt.Errorf("multiple errors occurred: [%s]", combinedErrorMsg)
+}