有人能帮助将遗留代码转换为TDD代码吗?初学者拔头发
本文关键字：代码 TDD 初学者 头发 转换 帮助 | 更新日期: 2023-09-27 18:21:41
我正在尝试使用TDD重写一个方法。
这是没有数据库逻辑的原始方法，下面是我试图重写它。它不完整，因为我只是撞到了墙上，不知道如何完成它。
我正在努力学习，但无法解决，所以需要一些帮助。感谢阅读。
//Original Method
public class StringCalculator()
{
public List<ShipmentInformation> GetBoxRange(int BoxSize, int Quantity, ref string DVDType, ref string ErrorMessage)
{
//Get Connection String
//Do Database Queries and return shipmentInfo variable as List<ShipmentInformation>
var DVDTotals = shipmentInfo.GroupBy(x => x.DVDType).Select(x => new { DVDType = x.Key, Total = x.Sum(y => (y.DVDEndID - y.DVDStartID) + 1) });
if (DVDTotals.Count() == 0 || DVDTotals.All(x => x.Total < Quantity))
{
ErrorMessage = "There is not enough data to create a shipment based on the quantity";
return new List<ShipmentInformation>();
}
//Select the one with the largest amount of stock
var LargestDVDType = DVDTotals.Aggregate((l, r) => l.Total > r.Total ? l : r).DVDType;
var LargestDVDTypeSelection = shipmentInfo.Where(x => x.DVDType == LargestDVDType);
long previousDVDStartID = 0;
//Make sure ranges are sequential
List<ShipmentInformation> SequentialBoxResults = new List<ShipmentInformation>();
foreach (var item in LargestDVDTypeSelection)
{
if (item.DVDStartID - previousDVDStartID == BoxSize || previousDVDStartID == 0)
{
SequentialBoxResults.Add(item);
}
else
{
SequentialBoxResults.Clear();
SequentialBoxResults.Add(item);
}
previousDVDStartID = item.DVDStartID;
if (BoxSize * SequentialBoxResults.Count == Quantity)
{
break;
}
}
if (SequentialBoxResults.Count == 0 || BoxSize * SequentialBoxResults.Count != Quantity)
{
ErrorMessage = "There are no available ranges to create a shipment based on the quantity";
return new List<ShipmentInformation>(); ;
}
List<ShipmentInformation> Results = new List<ShipmentInformation>();
var Genres = SequentialBoxResults.GroupBy(x => x.Genre);
foreach (var Genre in Genres)
{
var orderedGenres = Genre.OrderBy(x => x.DVDStartID);
ShipmentInformation shipment = new ShipmentInformation();
shipment.Genre = Genre.Key;
shipment.DVDStartID = orderedGenres.First().DVDStartID;
var lastItem = orderedGenres.Last();
shipment.DVDEndID = lastItem.DVDEndID;
shipment.DVDType = lastItem.DVDType;
Results.Add(shipment);
}
//We have our shipment recordsnow split them up if any are over 75000
for (int i = 0; i < Results.Count; i++)
{
long rangeSize = Results[i].DVDEndID - Results[i].DVDStartID + 1;
double noOfLoops = Math.Ceiling(rangeSize / 75000D);
long remainder = rangeSize % 75000;
if (noOfLoops > 1)
{
bool AddedRecord = false;
for (int j = 0; j < noOfLoops; j++)
{
long shipmentSize = 0;
if (j == (noOfLoops - 1))
{
shipmentSize = remainder;
if (AddedRecord)
Results.Add(new ShipmentInformation() { DVDStartID = Results.Last().DVDEndID + 1, DVDEndID = Results.Last().DVDEndID + 1 + (shipmentSize - 1), Genre = Results.Last().Genre });
else
Results.Add(new ShipmentInformation() { DVDStartID = Results[i].DVDEndID + 1, DVDEndID = Results[i].DVDEndID + 1 + (shipmentSize - 1), Genre = Results[i].Genre });
}
else
{
shipmentSize = 75000;
if (j == 0)
{
Results[i].DVDEndID = Results[i].DVDStartID + (shipmentSize - 1);
}
else if (j == 1)
{
Results.Add(new ShipmentInformation() { DVDStartID = Results[i].DVDEndID + 1, DVDEndID = Results[i].DVDEndID + 1 + (shipmentSize - 1), Genre = Results[i].Genre });
AddedRecord = true;
}
else
{
Results.Add(new ShipmentInformation() { DVDStartID = Results.Last().DVDEndID + 1, DVDEndID = Results.Last().DVDEndID + 1 + (shipmentSize - 1), Genre = Results.Last().Genre });
AddedRecord = true;
}
}
}
}
}
return Results;
}
}
//New Method with Tests
public List<ShipmentInformation> GetBoxRange(int BoxSize, int Quantity, DateTime CutOffDate, IDataProvider Provider, ref string DVDType, ref string ErrorMessage)
{
if (BoxSize == 0)
{
ErrorMessage = "Please enter a BoxSize";
}
if (Quantity == 0)
{
ErrorMessage = "Please enter a Quantity";
}
if (!String.IsNullOrWhiteSpace(ErrorMessage))
{
return new List<ShipmentInformation>();
}
List<ShipmentInformation> Data = Provider.GetData();
if (Data.Count == 0)
{
ErrorMessage = "Database failed to return data";
return new List<ShipmentInformation>();
}
List<ShipmentInformation> OrderedData = GetSequentialBoxes(Data, BoxSize, Quantity);
if (OrderedData.Count == 0)
{
ErrorMessage = "No sequential data found";
return new List<ShipmentInformation>();
}
//I'm not sure how to continue from here - I started writing GetRecordsPerGenre but got lost in what I'm trying to do. I still need to check if size is over 75000
return OrderedData;
}
public virtual List<ShipmentInformation> GetSequentialBoxes(List<ShipmentInformation> Data, int BoxSize, int Quantity)
{
if (Data.Count == 0)
return new List<ShipmentInformation>();
var orderedData = Data.OrderBy(x => x.DVDStartID);
if (!orderedData.SequenceEqual(Data))
return new List<ShipmentInformation>();
var DVDTotals = Data.GroupBy(x => x.DVDType).Select(x => new { DVDType = x.Key, Total = x.Sum(y => (y.DVDEndID - y.DVDStartID) + 1) });
if (DVDTotals.Count() == 0 || DVDTotals.All(x => x.Total < Quantity))
{
return new List<ShipmentInformation>();
}
var LargestDVDType = DVDTotals.Aggregate((l, r) => l.Total > r.Total ? l : r).DVDType;
Data = Data.Where(x => x.DVDType == LargestDVDType).ToList();
List<ShipmentInformation> returnData = new List<ShipmentInformation>();
long previousDVDStartID = 0;
foreach (var item in Data)
{
if (previousDVDStartID == 0 || item.DVDStartID - previousDVDStartID == BoxSize)
{
returnData.Add(item);
}
else
{
returnData.Clear();
returnData.Add(item);
}
previousDVDStartID = item.DVDStartID;
if (returnData.Count * BoxSize == Quantity)
break;
}
return returnData.OrderBy(x => x.DVDStartID).ToList();
}
public List<ShipmentInformation> GetRecordsPerGenre(List<ShipmentInformation> Data)
{
List<ShipmentInformation> Results = new List<ShipmentInformation>();
var Genres = Data.GroupBy(x => x.Genre);
foreach (var Genre in Genres)
{
var orderedGenres = Genre.OrderBy(x => x.DVDStartID);
ShipmentInformation shipment = new ShipmentInformation();
shipment.Genre = Genre.Key;
shipment.DVDStartID = orderedGenres.First().DVDStartID;
var lastItem = orderedGenres.Last();
shipment.DVDEndID = lastItem.DVDEndID;
shipment.DVDType = lastItem.DVDType;
Results.Add(shipment);
}
return Results;
}
//Tests
[TestFixture]
public class GetBoxRangeMethod
{
private StringCalculator CreateNewCalculator()
{
return new StringCalculator();
}
[TestCase(0, 1)]
[TestCase(1, 0)]
public void ZeroValuesForBoxSizeOrQuantity_ReturnsErrorAndEmptyList(int BoxSize, int Quantity)
{
StringCalculator sc = CreateNewCalculator();
string ErrorMessage = "";
string ChipType = "";
FakeDataProvier provider = new FakeDataProvier(new List<ShipmentInformation>());
List<ShipmentInformation> result = sc.GetBoxRange(BoxSize, Quantity, new DateTime(2012, 01, 01), "A", provider, ref ChipType, ref ErrorMessage);
Assert.AreNotEqual("", ErrorMessage);
Assert.AreEqual(0, result.Count);
}
[Test]
public void EmptyBookTypeString_ReturnsErrorAndEmptyList()
{
StringCalculator sc = CreateNewCalculator();
string ErrorMessage = "";
string ChipType = "";
FakeDataProvier provider = new FakeDataProvier(new List<ShipmentInformation>());
List<ShipmentInformation> result = sc.GetBoxRange(1, 1, new DateTime(2012, 01, 01), "", provider, ref ChipType, ref ErrorMessage);
Assert.AreNotEqual("", ErrorMessage);
Assert.AreEqual(0, result.Count);
}
[Test]
public void EmptyDBData_ReturnsErrorAndEmptyList()
{
StringCalculator sc = CreateNewCalculator();
string ErrorMessage = "";
string ChipType = "";
FakeDataProvier provider = new FakeDataProvier(new List<ShipmentInformation>());
List<ShipmentInformation> result = sc.GetBoxRange(1, 1, new DateTime(2012, 01, 01), "A", provider, ref ChipType, ref ErrorMessage);
Assert.AreNotEqual("", ErrorMessage);
Assert.AreEqual(0, result.Count);
}
[Test]
public void EmptyOrderedData_ReturnsErrorAndEmptyList()
{
FakeShipmentCalculator sc = new FakeShipmentCalculator();
string ErrorMessage = "";
string ChipType = "";
FakeDataProvier provider = new FakeDataProvier(new List<ShipmentInformation>() { new ShipmentInformation() { ChipType = "A", StartPP = 1, EndPP = 2, JacketNo = "A", ReqNo = "B" } });
List<ShipmentInformation> result = sc.GetBoxRange(1, 1, new DateTime(2012, 01, 01), "A", provider, ref ChipType, ref ErrorMessage);
Assert.AreNotEqual("", ErrorMessage);
Assert.AreEqual(0, result.Count);
}
}
//Integration test
[TestFixture]
public class GetDataMethod
{
}
[TestFixture]
public class GetSequentialBoxes
{
private StringCalculator CreateNewCalculator()
{
return new StringCalculator();
}
[Test]
public void MethodCalled_DoesntReturnNull()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> result = sc.GetSequentialBoxes(new List<ShipmentInformation>(), 100, 1);
Assert.IsNotNull(result);
}
[Test]
public void EmptyDataPassedIn_ReturnsEmptyData()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> result = sc.GetSequentialBoxes(new List<ShipmentInformation>(), 100, 1);
Assert.AreEqual(0, result.Count);
}
[Test]
public void OrderedData_ReturnsOrderedData()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> inputData = new List<ShipmentInformation>();
ShipmentInformation data = new ShipmentInformation() { ChipType = "A", StartPP = 1, EndPP = 2, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "A", StartPP = 3, EndPP = 4, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
List<ShipmentInformation> result = sc.GetSequentialBoxes(inputData, 2, 1);
ShipmentInformation firstItem = result.FirstOrDefault();
ShipmentInformation secondItem = result.LastOrDefault();
Assert.IsTrue(firstItem.StartPP == 1 && secondItem.StartPP == 3);
}
[Test]
public void UnOrderedData_ReturnsEmptyData()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> inputData = new List<ShipmentInformation>();
ShipmentInformation data = new ShipmentInformation() { ChipType = "A", StartPP = 3, EndPP = 4, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "A", StartPP = 1, EndPP = 2, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
int NUMBER_GREATER_THAN_ONE = 2;
List<ShipmentInformation> result = sc.GetSequentialBoxes(inputData, NUMBER_GREATER_THAN_ONE, 1);
Assert.AreEqual(0, result.Count);
}
[Test]
public void SequenceJumps_ClearsListAndStartsAgain()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> inputData = new List<ShipmentInformation>();
ShipmentInformation data = new ShipmentInformation() { ChipType = "A", StartPP = 1, EndPP = 2, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "A", StartPP = 5, EndPP = 6, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
List<ShipmentInformation> result = sc.GetSequentialBoxes(inputData, 2, 1);
Assert.IsTrue(result.First().StartPP == 5);
}
[Test]
public void LargestNumberOfItemsWithSameChipType_ReturnsDataWithOnlyThatChipType()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> inputData = new List<ShipmentInformation>();
ShipmentInformation data = new ShipmentInformation() { ChipType = "A", StartPP = 1, EndPP = 2, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "A", StartPP = 3, EndPP = 4, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "B", StartPP = 5, EndPP = 6, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
int BoxSizeSlashSequenceJumpAllowed = 2;
List<ShipmentInformation> result = sc.GetSequentialBoxes(inputData, BoxSizeSlashSequenceJumpAllowed, 1);
Assert.IsTrue(result.All(x => x.ChipType == "A"));
}
[Test]
public void TotalNumberOfRecordsPerChipTypeLessThanQuantity_ReturnsEmptyData()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> inputData = new List<ShipmentInformation>();
ShipmentInformation data = new ShipmentInformation() { ChipType = "A", StartPP = 1, EndPP = 2, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "A", StartPP = 3, EndPP = 4, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "B", StartPP = 5, EndPP = 6, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
int BoxSizeSlashSequenceJumpAllowed = 2;
int Quantity = 5;
List<ShipmentInformation> result = sc.GetSequentialBoxes(inputData, BoxSizeSlashSequenceJumpAllowed, Quantity);
Assert.AreEqual(0, result.Count);
}
[Test]
public void DataReturned_WhenQuantityReached()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> inputData = new List<ShipmentInformation>();
ShipmentInformation data = new ShipmentInformation() { ChipType = "A", StartPP = 1, EndPP = 2, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "A", StartPP = 3, EndPP = 4, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
data = new ShipmentInformation() { ChipType = "A", StartPP = 5, EndPP = 6, JacketNo = "A", ReqNo = "B" };
inputData.Add(data);
int BoxSizeSlashSequenceJumpAllowed = 2;
int Quantity = 4;
List<ShipmentInformation> result = sc.GetSequentialBoxes(inputData, BoxSizeSlashSequenceJumpAllowed, Quantity);
Assert.AreEqual(2, result.Count);
}
}
[TestFixture]
public class GetRecordsPerGenre
{
private StringCalculator CreateNewCalculator()
{
return new StringCalculator();
}
[Test]
public void MethodCalled_DoesntReturnNull()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> result = sc.GetRecordsPerSerialRange(new List<ShipmentInformation>());
Assert.IsNotNull(result);
}
[Test]
public void EmptyDataPassedIn_ReturnsEmptyData()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> result = sc.GetRecordsPerSerialRange(new List<ShipmentInformation>());
Assert.AreEqual(0, result.Count);
}
[Test]
public void Data_ReturnsGroupedByData()
{
StringCalculator sc = CreateNewCalculator();
List<ShipmentInformation> inputData = new List<ShipmentInformation>();
ShipmentInformation data = new ShipmentInformation();
data.ChipType = "A";
data.ReqNo = "B";
data.JacketNo="C";
data.StartPP = 1;
data.EndPP = 2;
inputData.Add(data);
data = new ShipmentInformation();
data.ChipType = "A";
data.ReqNo = "B";
data.JacketNo = "C";
data.StartPP = 1;
data.EndPP = 2;
inputData.Add(data);
List<ShipmentInformation> result = sc.GetRecordsPerSerialRange(inputData);
Assert.AreEqual(1, result.Count);
}
}
在Jon，你可能为了一个角落而吃得太多了。用一个新特性而不是现有特性来实现TDD。在这个场景中，您不仅引入了测试、TDD和嘲讽。但现在您也引入了重构（又是一个新概念）。
一旦您掌握了关于greenfield代码的TDD的基础知识，就可以将其应用于brownfield代码以及重构。
最后一点：TDD不需要mocking，mocking是一个单独的概念，可以很好地与TDD配合使用，但它不是必需的。简单地说，TDD就是通过测试来推动设计。
为了有效地进行单元测试，您应该遵守一些设计原则。松耦合、关注点分离和依赖注入。原因是，如果没有，你将无法在测试中使用模拟（这是你需要做的）
我注意到在你上面的代码中的第一个方法：
//Get Connection String
//Do Database Queries and return shipmentInfo variable as List<ShipmentInformation>
由此我推测，您实际上实例化了查询DB所需的一切。这不是最佳实践，也可能是问题的根源。你应该依赖抽象，而不是具体化。应使用构造函数注入传递"存储库"接口（或类似接口）的实例。
一本让你开始的好书是：http://www.amazon.co.uk/Professional-ASP-NET-Design-Patterns-Millett/dp/0470292784
希望这能有所帮助。