Expose TypeMapper

[GilianJuice]

Is your feature request related to a problem? Please describe.
I sometimes work on applications that need metadata of tables and columns. I use queries on information_schema to get this information. I would love it if I could use the MySqlConnector.Core.TypeMapper class so that I can map the results from information_schema.columns to the MySqlConnector.MySqlDbType enum, but I can't since that class is internal. Because of that, I have to write my own mapper, which is bad since MySqlConnector already has a good one.

Describe the solution you'd like
Change the modifier of MySqlConnector.Core.TypeMapper from internal sealed class to public sealed class.

Describe alternatives you've considered
I have considered the following options, which are all bad/inconvenient:

• Write my own mapper -> This is reinventing the wheel.
• Copy the code of MySqlConnector.Core.TypeMapper to my own class and use that one -> I need to check after every update of MySqlConnector to see if this class has changed and if I need to copy those changes.
• Use reflection to call methods of MySqlConnector.Core.TypeMapper.Instance -> This is very fragile and could break with library updates.
• Find alternative solutions -> I have not been able to find any.

Additional context
I don't think any context I can explain is relevant for this request. I only wonder if there is a reason for this class being internal. If not, I could maybe make a PR myself to change it.

[bgrainger]

I only wonder if there is a reason for this class being internal.

Mainly that it wasn't designed to be part of the public API (where any changes might be breaking changes for clients, etc.).

If not, I could maybe make a PR myself to change it.

I wouldn't accept a PR that just made that type public, as that would put a lot of functions into the public API of this library (and limit MySqlConnector's ability to evolve in the future).

A new public class with a limited API (that delegates to TypeMapper) is probably the way I'd approach this problem, but I haven't thought about how that would be designed yet.

[GilianJuice]

Thanks for explaining, that makes sense. I haven't worked (much) on big projects like this, so I didn't consider that. For now I will work with a very simple self-made mapper in my project, that works well enough for what we need. I can always replace that in the future if/when this request gets implemented.