A few years back, JSON crossed the “really good hammer” threshold. It has a good balance of being human readable, relatively compact, and simple to parse. It thus has become the go-to format for everything. “KoHHeKT” inherited a service which generates some JSON from an in-memory tree structure. This is exactly the kind of situation where JSON shines, and it would be trivial to employ one of the many JSON serialization libraries available for C# to generate JSON on demand.

Orrrrr… you could use LINQ aggregations, string formatting and trims…

private static string GetChildrenValue(int childrenCount)
{
        string result = Enumerable.Range(0, childrenCount).Aggregate("", (s, i) => s + $"\"{i}\",");
        return $"[{result.TrimEnd(',')}]";
}

Now, the concatenation and trims and all of that is bad. But I’m mostly stumped by what this method is supposed to accomplish. It’s called GetChildrenValue, but it doesn’t return a value- it returns an array of numbers from 0 to children count. Well, not an array, obviously- a string that can be parsed into an array. And they’re not actually numbers- they’re enclosed in quotes, so it’s actually text, not that any JavaScript client would care about the difference.

Why? How is this consumed? KoHHeKT couldn’t tell us, and we certainly aren’t going to figure it out from this block. But it is representative of the entire JSON constructing library- aggregations and concatenations with minimal exception handling and no way to confirm that it output syntactically valid JSON because nothing sanitizes its inputs.

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