Test Assertions¶

TUnit source-generated assertion extensions for Roslyn symbols, emit results, and compilations.

These assertions use TUnit's [GenerateAssertion] attribute to generate fluent Assert.That(x).IsNamed("Foo") style assertions automatically.

ValidSymbol Assertions¶

Assertions for ValidSymbol<T> — a wrapper guaranteeing a non-null Roslyn symbol.

Name¶

await Assert.That(symbol).IsNamed("Customer");
await Assert.That(symbol).NameStartsWith("I");
await Assert.That(symbol).NameEndsWith("Service");
await Assert.That(symbol).NameContains("Base");

Accessibility¶

await Assert.That(symbol).IsPublicSymbol();
await Assert.That(symbol).IsPrivateSymbol();
await Assert.That(symbol).IsInternalSymbol();
await Assert.That(symbol).IsProtectedSymbol();

Modifiers¶

await Assert.That(symbol).IsStaticSymbol();
await Assert.That(symbol).IsAbstractSymbol();
await Assert.That(symbol).IsSealedSymbol();
await Assert.That(symbol).IsVirtualSymbol();

Attributes¶

await Assert.That(symbol).HasAttribute("ObsoleteAttribute");
await Assert.That(symbol).DoesNotHaveAttribute("Obsolete");

Named Type Assertions¶

For ValidSymbol<INamedTypeSymbol> and OptionalSymbol<INamedTypeSymbol>:

await Assert.That(type).IsClassSymbol();
await Assert.That(type).IsInterfaceSymbol();
await Assert.That(type).IsStructSymbol();
await Assert.That(type).IsRecordSymbol();
await Assert.That(type).IsEnumSymbol();
await Assert.That(type).IsDelegateSymbol();
await Assert.That(type).IsPartialSymbol();
await Assert.That(type).IsGenericSymbol();
await Assert.That(type).HasTypeParameterCount(2);

Method Assertions¶

For ValidSymbol<IMethodSymbol> and OptionalSymbol<IMethodSymbol>:

await Assert.That(method).IsAsyncSymbol();
await Assert.That(method).ReturnsVoid();
await Assert.That(method).HasParameterCount(2);
await Assert.That(method).IsExtension();
await Assert.That(method).IsGeneric();
await Assert.That(method).IsConstructor();
await Assert.That(method).IsOperator();
await Assert.That(method).HasReturnType();

Property Assertions¶

For ValidSymbol<IPropertySymbol> and OptionalSymbol<IPropertySymbol>:

await Assert.That(prop).IsReadOnlySymbol();
await Assert.That(prop).IsWriteOnly();
await Assert.That(prop).HasGetter();
await Assert.That(prop).HasSetter();
await Assert.That(prop).IsIndexer();
await Assert.That(prop).HasInitOnlySetter();
await Assert.That(prop).IsRequired();

Field Assertions¶

For ValidSymbol<IFieldSymbol> and OptionalSymbol<IFieldSymbol>:

await Assert.That(field).IsReadOnlySymbol();
await Assert.That(field).IsConst();
await Assert.That(field).IsVolatile();
await Assert.That(field).HasConstantValue();

OptionalSymbol Assertions¶

For OptionalSymbol<T> — a nullable wrapper:

await Assert.That(symbol).HasValue();
await Assert.That(symbol).IsEmpty();

OptionalEmit Assertions¶

For OptionalEmit — the result of calling .Emit():

await Assert.That(emit).IsSuccessful();
await Assert.That(emit).HasFailed();
await Assert.That(emit).HasValue();
await Assert.That(emit).IsEmpty();
await Assert.That(emit).HasDiagnostics();
await Assert.That(emit).HasNoDiagnostics();
await Assert.That(emit).HasErrors();
await Assert.That(emit).HasWarnings();
await Assert.That(emit).CodeContains("partial class");
await Assert.That(emit).CodeDoesNotContain("sealed");

Compilation Assertions¶

await Assert.That(compilation).IsSuccessful();

IsSuccessful returns an AssertionResult with detailed error output including all compilation errors and the source tree on failure.