private async Task AssertTestCase_SingleExpression(WhenChangedHostBuilder hostTypeInfo, BaseUserSourceBuilder hostPropertyTypeInfo, bool typesHaveSameRoot)
{
hostTypeInfo.WithInvocation(InvocationKind.MemberAccess, x => x.Value);
var propertyTypeSource = typesHaveSameRoot ? string.Empty : hostPropertyTypeInfo.BuildRoot();
var fixture = await WhenChangedFixture.Create(hostTypeInfo, x => TestContext.WriteLine(x), ("PropertyTypeSource.cs", propertyTypeSource)).ConfigureAwait(false);
fixture.RunGenerator(out var compilationDiagnostics, out var generatorDiagnostics);
generatorDiagnostics.Where(x => x.Severity >= DiagnosticSeverity.Warning).Should().BeEmpty();
compilationDiagnostics.Where(x => x.Severity >= DiagnosticSeverity.Warning).Should().BeEmpty();
var host = fixture.NewHostInstance();
host.Value = fixture.NewValuePropertyInstance();
var observable = host.GetWhenChangedObservable(_ => TestContext.WriteLine(fixture.Sources));
object value = null;
observable.Subscribe(x => value = x);
host.Value.Should().Be(value);
host.Value = fixture.NewValuePropertyInstance();
host.Value.Should().Be(value);
host.Value = null;
host.Value.Should().Be(value);
}
