IObservable <Company> Subscribe(ResolveEventStreamContext context, ContextFactory contextFactory, ILogger logger)
{
long lastId = 0;
var inner = Observable.Using(
token => Task.FromResult(contextFactory.BuildContext()),
async(ctx, token) =>
{
try
{
var companies = await GetCompanies(context, ctx, lastId, token: token);
if (companies.Any())
{
lastId = companies.Max(transaction => transaction.Id);
}
return(companies.ToObservable());
}
catch (OperationCanceledException)
{
logger.LogInformation("Companies subscription has been cancelled.");
return(Observable.Empty <Company>());
}
catch (Exception e)
{
logger.LogError(e, "Unable to get companies.");
return(Observable.Empty <Company>());
}
});
return(Observable.Interval(TimeSpan.FromSeconds(1)).SelectMany(_ => inner));
}
public void RetrieveStudentsTest()
{
using (var appContext = ContextFactory.BuildContext())
{
// Setup
var foo = new Student()
{
Name = "John Snow", Address = "Winterfell Avenue 39b"
};
var bar = new Student()
{
Name = "Grey Worm", Address = "Tent Park 13122"
};
appContext.Students.Add(foo);
appContext.Students.Add(bar);
appContext.SaveChanges();
// Act
var data = appContext.Students;
// Assert
Assert.Contains(data, e => e.Id == foo.Id);
Assert.Contains(data, e => e.Id == bar.Id);
// Cleanup
appContext.Students.Remove(foo);
appContext.Students.Remove(bar);
appContext.SaveChanges();
}
}