生成类型提供程序的编译时错误

Question

I've run into an issue with on a branch of FSharp.Data.SqlClient I am working on with the generative SqlEnumProvider type provider. When the test project attemps to use a provided type, I get the following compile-time error:

A problem occurred writing the binary 'C:\\code\\FSharp.Data.SqlClient\\src\\SqlClient.Tests\\obj\\Debug\\net451\\SqlClient.Tests.dll': Error in pass3 for type FSharp.Data.EnumTests, error: Error in GetMethodRefAsMethodDefIdx for mref = ("Parse", "TinyIntMapping"), error: Exception of type 'Microsoft.FSharp.Compiler.AbstractIL.ILBinaryWriter+MethodDefNotFound' was thrown.

At design time, everything appears to be working as expected. (I have intellisense on the provided types, etc.)

I attempted the workaround suggested here , but no joy.

Answer 1

How about using the container approach where you place all of the provided types into a container, decanting each one you need?

I used this in quite a few of my type providers, have a look at the iOS designer type provider for reference: https://github.com/xamarin/fsharp-iOS-designer/blob/master/src/Xamarin.iOSProviders/iOSDesignerProvider.fs#L64-L86

Answer 2

It turns out the answer was in the sample template in the SDK, I just wasn't reading it closely enough:

• The provider type (eg, SqlEnumProvider ) should be added to the executing assembly.
• The root types (eg, SqlEnumProvider<"SELECT * FROM (VALUES(('One'), 1), ('Two', 2)) AS T(Tag, Value)"> ) should be added to the provided assembly.

In the failing code, we were adding the root types to both assemblies.