// OverwriteStructTag overwrites the struct tag completely
func OverwriteStructTag(tag *ast.BasicLit, tagName string, offset *int, data []byte) []byte {
val := tag.Value
start := int(tag.Pos()) + *offset - 1
end := int(tag.End()) + *offset - 1
length := len(val)
oldLength := end - start
// Delete the original tag
data = DeleteRange(data, start, end)
var newTag string
if options.AppendMode == Append {
oldTag := removeIndex(removeIndex(val, 0), len(val)-2)
newTag = fmt.Sprintf("`%s:\"%s\" %s`", options.Tag, tagName, oldTag)
} else {
newTag = fmt.Sprintf("`%s:\"%s\"`", options.Tag, tagName)
}
numSpaces := len(newTag) - oldLength - 1
var spaces string
// Can't pass a negative number to strings.Repeat()
// it will cause a panic because it passes this number directly to make()
if numSpaces > 0 {
spaces = strings.Repeat(" ", numSpaces)
}
newTag = fmt.Sprintf("%s%s", spaces, newTag)
localOffset := len(newTag) - length
*offset += localOffset
// Insert new tag
data = Insert(data, []byte(newTag), start)
return data
}
