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Metalama 2024.0

The primary goal of this release is to provide support for C# 12. Additionally, it addresses a few remaining tasks from previous releases when we made the Metalama source code available.

Platform update

  • Metalama.Compiler: Merged Roslyn 4.8 RTM.
  • Support for C# 12:
    • Default lambda parameters
    • Inline arrays in run-time code
    • nameof: Access to instance members from a static context
    • Primary constructors
    • Type aliases
    • Collection expressions (also known as collection literals) like [1,2,..array]
    • AppendParameter advice (used in dependency injection scenarios) in primary constructors
    • Primary constructor parameters in initializer expressions

Multi-version C# support

Metalama 2024.0 is the first version to support multiple versions of C#.

  • Metalama uses different C# code generation patterns based on the C# version of the current project. The supported versions are 10, 11, and 12.
  • Metalama identifies the version used by each T# template and reports an error if a template is used in a project targeting a lower version of C# than required. The new MSBuild property MetalamaTemplateLanguageVersion limits the version of C# that can be used in templates. Define this property to prevent the accidental use of a higher version of C# than intended.
  • Templates can't conditionally generate code patterns according to the C# version of the target project.

Other improvements

  • Deterministic build: Now implemented for all Metalama assemblies. This feature enables you to verify that the released binaries were built from our source code. The only differences between the official assemblies and your own builds should be strong-name and Authenticode signatures. Building Metalama from source code requires a source subscription, which is available for an additional fee.
  • Symbol packages: Published for all Metalama NuGet packages, enabling source code debugging via SourceLink.
  • Warning and error deduplication: Currently not supported in the user API.
  • Licensing: Aspect inheritance is now permitted for all license types.

Breaking changes

In the RefKind enum, In and RefReadOnly are no longer synonymous.

In progress

We have been working on the following projects, but they are not yet stable:

  • Metalama.Patterns.Observability is an aspect implementing the INotifyPropertyChanged interface. It supports computed properties and child objects.
  • Metalama.Patterns.Xaml are aspects implementing WPF commands and dependency properties. This package has been renamed to Metalama.Patterns.Wpf in Metalama 2024.2.