public void WhenTypeImplementsIWriteDocumentThenWriteToStreamAsyncWritesCollectionJson() { var doc = new TestWriteDocument(); var stream = new MemoryStream(); formatter.WriteToStreamAsync(doc.GetType(), doc, stream, null, null).Wait(); var reader = new StreamReader(stream); stream.Position = 0; var content = reader.ReadToEnd(); content.ShouldContain("\"TestValue\""); }