Write unit tests for factory methods

[monkey0506]

Describe the issue

The factory methods (FromAction, FromFunc, and FromFunctionPointer) are implemented only via the source code that we are generating. If we fail to generate source code for any factory method that is actually used, then it will throw a NotImplementedException at runtime. This makes our source generation testable, because we can simply check whether the factory methods throw an exception when invoked.

Proposed solution

While the API is quite extensive, unit tests should be written for some iteration of every API method.

Because the interfaces are generic, it is inherently impossible to exhaustively test every possible type argument, but at minimum we should test two distinct types (that cannot be cast to each other) per type argument. If our source generation fails to cover a real use-case, this may produce an InvalidCastException or NotImplementedException.

Except for INativeAction and IUnmanagedAction (which take no type arguments), each other interface should provide tests for explicit type arguments (e.g., INativeAction<string>) and open type arguments (e.g., INativeAction<X> where X is an enclosing generic type or generic method's type parameter).

Factory methods which take the TMarshaller type parameter should be tested with at least two explicit marshallers and an open type argument.

The interface can be marked off here when tests have been written to satisfy all of the above conditions:

• INativeAction
• INativeAction<T>
• INativeAction<T1, T2>
• INativeAction<T1, T2, T3>
• INativeAction<T1, T2, T3, T4>
• INativeAction<T1, T2, T3, T4, T5>
• INativeAction<T1, T2, T3, T4, T5, T6>
• INativeAction<T1, T2, T3, T4, T5, T6, T7>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>
• INativeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>
• INativeFunc<TResult>
• INativeFunc<T, TResult>
• INativeFunc<T1, T2, TResult>
• INativeFunc<T1, T2, T3, TResult>
• INativeFunc<T1, T2, T3, T4, TResult>
• INativeFunc<T1, T2, T3, T4, T5, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, TResult>
• INativeFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TResult>
• IUnmanagedAction
• IUnmanagedAction<T, U>
• IUnmanagedAction<T1, T2, U1, U2>
• IUnmanagedAction<T1, T2, T3, U1, U2, U3>
• IUnmanagedAction<T1, T2, T3, T4, U1, U2, U3, U4>
• IUnmanagedAction<T1, T2, T3, T4, T5, U1, U2, U3, U4, U5>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, U1, U2, U3, U4, U5, U6>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, U1, U2, U3, U4, U5, U6, U7>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, U1, U2, U3, U4, U5, U6, U7, U8>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, U1, U2, U3, U4, U5, U6, U7, U8, U9>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13, U14>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13, U14, U15>
• IUnmanagedAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13, U14, U15, U16>
• IUnmanagedFunc<TResult, UResult>
• IUnmanagedFunc<T, TResult, U, UResult>
• IUnmanagedFunc<T1, T2, TResult, U1, U2, UResult>
• IUnmanagedFunc<T1, T2, T3, TResult, U1, U2, U3, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, TResult, U1, U2, U3, U4, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, TResult, U1, U2, U3, U4, U5, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, TResult, U1, U2, U3, U4, U5, U6, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, TResult, U1, U2, U3, U4, U5, U6, U7, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, TResult, U1, U2, U3, U4, U5, U6, U7, U8, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, TResult, U1, U2, U3, U4, U5, U6, U7, U8, U9, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, TResult, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, TResult, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, TResult, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, TResult, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, TResult, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13, U14, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, TResult, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13, U14, U15, UResult>
• IUnmanagedFunc<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TResult, U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13, U14, U15, U16, UResult>

Additional considerations

All interface methods and properties other than the factory methods are provided through real implementations. If testing those implementations is desired, that will be handled by a separate issue.

[monkey0506]

The current GenericReferenceSymbolTree fails abysmally while writing these unit tests. See monkey0506/Monkeymoto.GeneratorUtils.GenericSymbolReferenceTree#3.

[monkey0506]

I have rewritten the core implementation that drives the GenericSymbolReferenceTree and the performance issues have seemingly been resolved. Unfortunately, these changes broken open generic interceptors (they are not recognized as being open generics) and factory methods that are invoked in more than one source location (separate implementation classes with the same name are generated).

I'm not sure if this is a fault in the values returned from GenericSymbolReferenceTree or if this is a fault in this project. I will need to test this further before merging any changes.

Edit: These issues have been resolved.