public async Task GetWithPaginationAsync__Number_of_elements_on_single_page_is_less_than_page_size__Should_return_all_these_elements()
{
using (var factory = new DbContextFactory())
{
using (var context = await factory.CreateContextAsync())
{
context.Tickets.RemoveRange(await context.Tickets.ToArrayAsync());
await context.SaveChangesAsync();
}
using (var context = await factory.CreateContextAsync())
{
for (int i = 0; i < 10; i++)
{
await context.Tickets.AddAsync(new Ticket { Id = i.ToString() });
}
await context.SaveChangesAsync();
}
using (var context = await factory.CreateContextAsync())
{
var service = new TicketDbService(context, _logger);
// Page will be first with 6 elements and second with 4 elements. Second page will be return.
var result = await service.GetWithPaginationAsync(2, 6);
// More generic solution is: Count() should be count of elements in resource % pageSize.
result.Count().Should().Be(4);
}
}
}
public async Task GetWithPaginationAsync__Page_size_is_negative__Should_throw_ArgumentOutOfRangeException()
{
var service = new TicketDbService(_dbContextMock.Object, _logger);
Func <Task> action = async() => await service.GetWithPaginationAsync(3, -10);
await action.Should().ThrowExactlyAsync <ArgumentOutOfRangeException>("Because page size cannot be negative number.");
}
public async Task GetWithPaginationAsync__Page_number_is_less_than_1__Should_throw_ArgumentOutOfRangeException()
{
var service = new TicketDbService(_dbContextMock.Object, _logger);
Func <Task> action = async() => await service.GetWithPaginationAsync(0, 10);
await action.Should().ThrowExactlyAsync <ArgumentOutOfRangeException>("Because page number cannot be less than 1.");
}
public async Task GetWithPaginationAsync__Resource_is_null__Should_throw_InternalDbServiceException()
{
using (var factory = new DbContextFactory())
{
using (var context = await factory.CreateContextAsync())
{
context.Tickets = null as DbSet <Ticket>;
var service = new TicketDbService(context, _logger);
Func <Task> action = async() => await service.GetWithPaginationAsync(1, 1);
await action.Should().ThrowExactlyAsync <InternalDbServiceException>("Because resource reference is set to null");
}
}
}
public async Task GetWithPaginationAsync__Resource_is_empty__Should_return_empty_IEnumerable()
{
using (var factory = new DbContextFactory())
{
using (var context = await factory.CreateContextAsync())
{
context.Tickets.RemoveRange(await context.Tickets.ToArrayAsync());
await context.SaveChangesAsync();
}
using (var context = await factory.CreateContextAsync())
{
var service = new TicketDbService(context, _logger);
var result = await service.GetWithPaginationAsync(4, 5);
result.Count().Should().Be(0);
}
}
}
public async Task GetWithPaginationAsync__Resource_doesnt_exist__Should_throw_InternalDbServiceException()
{
using (var factory = new DbContextFactory())
{
using (var context = await factory.CreateContextAsync())
{
// Drop Tickets table.
context.Database.ExecuteSqlCommand("DROP TABLE [Tickets]");
}
using (var context = await factory.CreateContextAsync())
{
var service = new TicketDbService(context, _logger);
Func <Task> action = async() => await service.GetWithPaginationAsync(1, 1);
await action.Should().ThrowExactlyAsync <InternalDbServiceException>("Because resource doesnt exist and cannot get single instance of Ticket. " +
"NOTE Excaption actually is type of 'SqLiteError' only if database provider is SQLite.");
}
}
}
public async Task GetWithPaginationAsync__There_are_not_elements_on_single_page__Should_return_empty_IEnumerable()
{
using (var factory = new DbContextFactory())
{
using (var context = await factory.CreateContextAsync())
{
for (int i = 0; i < 10; i++)
{
await context.Tickets.AddAsync(new Ticket { Id = i.ToString() });
}
await context.SaveChangesAsync();
}
using (var context = await factory.CreateContextAsync())
{
var service = new TicketDbService(context, _logger);
// In this case is only 2 pages with any data.
var result = await service.GetWithPaginationAsync(4, 5);
result.Count().Should().Be(0);
}
}
}