Avro Source Generator is a .NET source generator that generates C# code from Avro schemas and is compatible with Apache Avro.
It produces models that use modern C# features, such as nullable reference types, init-only properties, required properties, and more.
Prerequisites
.NET SDK 8.0 or later
Usage
To use the Avro Source Generator in your project, add a reference to the AvroSourceGenerator package in your .csproj file:
dotnet add package AvroSourceGenerator
You can mark the AvroSourceGenerator package as PrivateAssets="all" to prevent projects referencing yours from getting a reference to it. Additionally, use to ensure that is not copied to the build output, since it is not required at runtime.
Supported values are public (default) and internal.
To change the access modifier of just one type, declare a partial definition for it using the desired access modifier, and annotate it with the Avro attribute.
using AvroSourceGenerator;
namespace example;
[Avro]
internal partial record User;
Records
By default, the generator uses record declarations for generated types whenever possible.
To modify this behavior for all generated types, include the AvroSourceGeneratorRecordDeclaration property in your .csproj file.
To change the declaration of just one type, declare a partial definition for it using the desired record or class keyword, and annotate it with the Avro attribute.
using AvroSourceGenerator;
namespace example;
[Avro]
public partial class User;
[!NOTE]
This feature is only applicable to Avro record schemas. Note that fixed and error schemas will always generate standard classes, as they are required to inherit from non-record types.
Language features
By default, the generated code utilizes the latest C# language features supported by the consuming project.
However, you can specify the C# language features to be used in the generated code to ensure compatibility with older versions of C#. For instance, setting LanguageFeatures.CSharp7_3 will restrict the generated code to features available in C# 7.3, such as excluding nullable reference types and records.
To configure language features for all generated code, include the AvroSourceGeneratorLanguageFeatures property in your .csproj file.
Supported values include all flags defined in the LanguageFeatures enum.
Parsing is case-insensitive and follows the default rules for flags (using Enum.Parse).
To change used features for just one type, declare a partial definition for it, and annotate it with the Avro attribute, specifying a LanguageFeatures argument.
using AvroSourceGenerator;
namespace example;
[Avro(LanguageFeatures = LanguageFeatures.CSharp7_3)]
public partial record User;
It is also possible to enable or disable specific features.
Example for using the latest features but excluding required properties:
using AvroSourceGenerator;
namespace example;
[Avro(LanguageFeatures = LanguageFeatures.Latest & ~LanguageFeatures.RequiredProperties)]
public partial record User;
Limitations
partial enum
In C#, enum types cannot be declared as partial, so it's not possible to configure code generation for just a single enum type.
A possible workaround for this is to wrap the enum schema in a record schema.
