Metalama

Fody

Fody is an extensible tool for weaving .NET assemblies. Manipulating the IL of an assembly as part of a build requires a significant amount of plumbing code. This plumbing code involves knowledge of both the MSBuild and Visual Studio APIs. Fody aims to eliminate that plumbing code through an extensible add-in model.

What are Fody weavers?

Fody weavers are plug-ins to the Fody platform. They generally implement a single feature. Fody weavers are packaged separately from Fody itself.

Fody strengths

  • Open-source plug-ins: Fody offers a variety of open-source plugins, making it easier to implement common programming patterns. These plugins are user-friendly, with ConfigureAwait, PropertyChanged, and a resource-embedding tool being particularly popular.

  • Method decorators: Fody’s MethodDecorator simplifies the implementation of simple patterns.

Fody limitations

  • Complexity: Using existing plugins and method decorators is straightforward, but creating custom patterns at the MSIL level can be intricate, particularly for non-trivial applications.

  • Cannot reference new members from source code: Since Fody processes output from the C# compiler, the source code cannot directly reference any members introduced by Fody.

  • Lack of aspect traceability: The code transformations Fody applies aren’t visible in the Integrated Development Environment (IDE). To view these changes, one must use a decompiler to examine the compiled application.

  • No commercial support: Both Fody and Mono.Cecil, the underlying library, are maintained by volunteers; no professional support offering stands behind them.

Fody alternatives