public void it_uses_aggregation()
{
// Arrange
var carReader = new CarReader();
var manufacturers = carReader.ProcessManufacturers("TestAssets/manufacturers.csv");
var cars = carReader.ProcessCars("TestAssets/fuel.csv");
var query = cars
.GroupBy(c => c.Manufacturer)
.Select(g =>
{
var results = g.Aggregate(new CarStatistics(),
(acc, c) => acc.Accumulate(c),
acc => acc.Compute());
return(new
{
Name = g.Key,
Avg = results.Average,
Max = results.Max,
Min = results.Min
});
})
.OrderByDescending(r => r.Max);
foreach (var result in query)
{
_testOutputHelper.WriteLine($"{result.Name}");
_testOutputHelper.WriteLine($"\t Max : {result.Max}");
_testOutputHelper.WriteLine($"\t Min : {result.Min}");
_testOutputHelper.WriteLine($"\t Avg : {result.Avg}");
}
}
public void it_uses_group_join()
{
// Arrange
var carReader = new CarReader();
var manufacturers = carReader.ProcessManufacturers("TestAssets/manufacturers.csv");
var cars = carReader.ProcessCars("TestAssets/fuel.csv");
var query = manufacturers
.GroupJoin(cars,
m => m.Name,
c => c.Manufacturer,
(m, g) =>
new
{
Manufacturer = m,
Cars = g
}
)
.OrderBy(m => m.Manufacturer.Name);
foreach (var group in query)
{
_testOutputHelper.WriteLine($"{group.Manufacturer.Name} : {group.Manufacturer.Headquarters}");
foreach (var car in group.Cars.OrderByDescending(g => g.Combined).Take(2))
{
_testOutputHelper.WriteLine($"\t{car.Name} : {car.Combined}");
}
}
}
public void it_uses_join_with_multiple_keys_to_combine_car_and_manufacturer()
{
// Arrange
var carReader = new CarReader();
var manufacturers = carReader.ProcessManufacturers("TestAssets/manufacturers.csv");
var cars = carReader
.ProcessCars("TestAssets/fuel.csv")
.Join(manufacturers,
c => new { c.Manufacturer, c.Year },
m => new { Manufacturer = m.Name, m.Year },
(car, manufacturer) =>
new
{
car.Manufacturer,
car.Name,
car.Combined,
manufacturer.Headquarters
})
.OrderByDescending(car => car.Combined)
.ThenBy(car => car.Name)
.Select(car => new
{
car.Headquarters,
car.Name,
car.Combined
});
foreach (var car in cars)
{
_testOutputHelper.WriteLine($"{car.Headquarters} - {car.Name} : {car.Combined}");
}
}
public void it_group_cars_by_manufacturer_and_shows_two_most_efficient_cars()
{
// Arrange
var carReader = new CarReader();
var manufacturers = carReader.ProcessManufacturers("TestAssets/manufacturers.csv");
var query = carReader
.ProcessCars("TestAssets/fuel.csv")
.GroupBy(car => car.Manufacturer.ToUpper())
.OrderBy(group => group.Key);
foreach (var group in query)
{
_testOutputHelper.WriteLine($"{group.Key} has {group.Count()} cars");
foreach (var car in group.OrderByDescending(g => g.Combined).Take(2))
{
_testOutputHelper.WriteLine($"\t{car.Name} : {car.Combined}");
}
}
}