Fatal error: Can't form Range with upperBound < lowerBound

[el-quick]

I am trying use asynchronous version on this way:

fuse.search(searchText, in: Keyword.searchables, completion: { results in
    ...
})

And I am getting this problem:

To take in account: Keyword.searchables is an array of string with near of 3000 items in it.

By the moment I solved it on this way:

for (index, item) in chunk.enumerated() {
    if let result = self.search(pattern, in: item) {
        if result.ranges.allSatisfy({ $0.upperBound > $0.lowerBound }) {
            items.append((index, result.score, result.ranges))
        }
    }
}

I know that's not the best way, and functionality comes affected, but it's working for me now.

Thanks in advance.