public async Task <string> SaveAsync(Submission submission)
{
var referenceNumber = referenceNumberGenerator.CreateNew();
var filePath = fileSystem.Path.Combine(submissionStoragePath, $"submission_{referenceNumber}.json");
if (fileSystem.File.Exists(filePath))
{
throw new Exception($"Submission with reference number r{referenceNumber} already exists");
}
using var fs = fileSystem.File.OpenWrite(filePath);
await JsonSerializer.SerializeAsync(fs, submission);
return(referenceNumber);
}
