/// <summary>
/// Page a queryable collection
/// </summary>
/// <param name="query">Queryable collection</param>
/// <param name="pageable">Pageable repository</param>
/// <typeparam name="TEntity">Entity type</typeparam>
/// <returns>Paged queryable collection</returns>
public static IQueryable <TEntity> Page <TEntity>(
this IQueryable <TEntity> query,
IPageableRepository <TEntity> pageable)
where TEntity : class
{
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
if (pageable == null)
{
throw new ArgumentNullException(nameof(pageable));
}
if (pageable.PageSize > 0)
{
if (pageable.PageNumber >= 1)
{
query = query.Skip((pageable.PageNumber - 1) * pageable.PageSize);
}
query = query.Take(pageable.PageSize);
}
return(query);
}
protected virtual async Task PageTest(int page, int pageSize, int totalRows, int expectedRows,
Func <IPageableRepository <Category>, Task <IEnumerable <Category> > > find)
{
// Create new empty database
using (var connection = CreateConnection())
{
InitializeDatabase(connection, "RepositoryTest_Page");
// Arrange
var categories = new List <Category>();
for (int i = 0; i < totalRows; i++)
{
var category = new Category
{
Name = $"{i % 10}",
Description = i.ToString()
};
categories.Add(category);
}
IPageableRepository <Category> categoryRepository = CreateCategoryRepository(connection);
await categoryRepository.CreateManyAsync(categories);
// Act
var pageItems = await find(categoryRepository.Page(page, pageSize));
// Assert
Assert.NotNull(pageItems);
Assert.Equal(expectedRows, pageItems.Count());
Assert.Equal(totalRows, categoryRepository.TotalItems);
Assert.Equal(pageSize == 0 ? 1 : (totalRows / pageSize) + 1, categoryRepository.TotalPages);
Assert.Equal(page, categoryRepository.PageNumber);
Assert.Equal(page < 2 ? 1 : ((page - 1) * pageSize) + 1, categoryRepository.StartIndex);
}
}
