Proposal: Add a TreatAsString field to QueryAttribute

[mark-pro]

The proposal arises from the need to pass custom types or structs which might represent types with rules and conversions. Most of these types can override ToString() which can then be called when constructing query parameters.

For example:

record readonly struct ZipCode(ushort ZipCode) {
    public override string ToString() =>
        ZipCode.ToString();
}

To solve the problem the proposal seeks to add a field to the QueryAttribute called TreatAsString.

The new field is used when the query string is created and simply calls the ToString() function on a type.

There is a workaround that is not documented. The current workaround is to implement IFormattable on the type, which feels redundant if ToString() is already implemented on a custom type.

[mark-pro]

I am open to suggestions on how to implement this functionality. In many of my project, both professional and personal, I find myself adding IFormattable to those types which feels a little clunky when I really need that complex type to be a string.

The solution could also work on types not owned by the implementer such as passing a GUID as a query parameter.

GetUser([Query(TreatAsString = true)] Guid userId).