Der Clean Code Vortrag zur Developer Week 2017

1. created by

2. created by
KISS
Im Prinzip ganz einfach

3. created by
Wegen Dir

4. created by
I. Säule

5. created by
public class Employee {
public String Forename {get; set;}
public String Lastname {get; set;}
public GenderTypes Sex {get; set;}
…
}

6. created by
public class Employee {
public String Forename {get; set;}
public String Lastname {get; set;}
public GenderTypes Sex {get; set;}
…
}

7. created by
public class Employee {
public String Forename {get; set;}
public String Lastname {get; set;}
public GenderTypes Sex {get; set;}
…
}

8. created by
public double GetCustomerDiscount
(int customerID, bool isPremium) {
if(isPremium) {
…
}
…
}

9. created by
public double GetCustomerDiscount
(int customerID, bool isPremium) {
if(isPremium) {
…
}
…
}

10. created by
public double GetCustomerDiscount
(int customerID, bool isPremium) {
if(isPremium) {
…
}
…
}

11. created by
public class GenericQueryHandler
: IRequest<T1, IResponse<T2 >>
{
public T1 Query{ get; }
public IResponse<T2> Execute(T1){…}
}

12. created by
public class GenericQueryHandler
: IRequest<T1, IResponse<T2 >>
{
public T1 Query{ get; }
public IResponse<T2> Execute(T1){…}
}

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14. created by
II. Säule

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public class EmployeeDTO : IEmployee {
public String Forename {get; set;}
public String Lastname {get; set;}
…
}

16. created by
public class EmployeeDTO : IEmployee {
public String Forename {get; set;}
public String Lastname {get; set;}
…
}

17. created by
public class EmployeeDTO : IEmployee {
public String Forename {get; set;}
public String Lastname {get; set;}
…
}

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public void Main () {
var strBaseUrl = „http: //127.0.0.1/api/v1“;
var intMaxCount = 10;
for (int i=0;i <=intMaxCount;i ++) {
…
}
…
}

19. created by
public void Main () {
var strBaseUrl = „http: //127.0.0.1/api/v1“;
var intMaxCount = 10;
for (int i=0;i <=intMaxCount;i ++) {
…
}
…
}

20. created by
public void Main () {
var strBaseUrl = „http: //127.0.0.1/api/v1“;
var intMaxCount = 10;
for (int i=0;i <=intMaxCount;i ++) {
…
}
…
}

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23. created by
III. Säule

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var xmlStructure =
XDocument.Parse(_xmlString);
var orderNumber =
xmlStructure.Element(„OrderNumber“).Value;

27. created byhttps://flic.kr/p/arUv5U - Eye Contact - Stranger 08 - Traveller_40
https://flic.kr/p/arUv5U

28. created by
Schizophrene Objekte
Captain Obvious
Tradition

29. created by
KISS

30. created by
KISS
=
Einfachheit & Fokus

31. created by

32. created by
Besserer
CODE

33. created by
1. FizzBuzz mit TDD
Gegeben:
Zahlenreihe von 1 bis 100
Anforderung 1:
Alle Zahlen, die durch 3 teilbar sind,
sollen als `Fizz` dargestellt werden

34. created by
1. FizzBuzz mit TDD
Test:
const number = 3;
MapToFizzBuzzValue(number)
.Should()
.Be(`Fizz`)

35. created by
1. FizzBuzz mit TDD
Lösung:
public String MapToFizzBuzzValue(int number)
{
return `Fizz`;
}

36. created by
1. FizzBuzz mit TDD
Anforderung 2:
Alle Zahlen, die durch 5 teilbar sind,
sollen als `Buzz` dargestellt werden

37. created by
1. FizzBuzz mit TDD
Test:
const number = 5;
MapToFizzBuzzValue(number)
.Should()
.Be(`Buzz`)

38. created by
1. FizzBuzz mit TDD
Lösung:
public string MapToFizzBuzzValue(int number)
{
if(number % 5 == 0) return `Buzz`;
return `Fizz`;
}

39. created by
1. FizzBuzz mit TDD
Anforderung 3:
Alle Zahlen, die durch 3 und 5 teilbar
sind, sollen als `FizzBuzz`
dargestellt werden

40. created by
1. FizzBuzz mit TDD
Test:
const number = 15;
MapToFizzBuzzValue(number)
.Should()
.Be(`FizzBuzz`)

41. created by
1. FizzBuzz mit TDD
Lösung:
public String MapToFizzBuzzValue(int number)
{
if(number % 15 == 0) return `FizzBuzz`;
if(number % 5 == 0) return `Buzz`;
return `Fizz`;
}

42. created by
1. FizzBuzz mit TDD
Anforderung 4:
Alle anderen Zahlen behalten ihren
Wert

43. created by
1. FizzBuzz mit TDD
Test:
const number = 23;
MapToFizzBuzzValue(number)
.Should()
.Be(`23`)

44. created by
1. FizzBuzz mit TDD
Lösung:
public String MapToFizzBuzzValue(int number)
{
if(number % 15 == 0) return `FizzBuzz`;
if(number % 3 == 0) return `Fizz`;
if(number % 5 == 0) return `Buzz`;
return number.ToString();
}

45. created by
2. Refactoring
Anforderung:
Es sollen Dateien aus einem FTP
Verzeichnis gelesen und verarbeitet
werden. In den Dateien sind
vermietbare Einheiten enthalten, die
je nach Status (Neu, Gelöscht,
Geändert) an das Vermietungsbüro
gemeldet werden sollen.

46. created by
2. Refactoring
Lösung: Im Prozess denken
var ftpFolder = new FtpFolder ();
GetFilesFrom (ftpFolder)
.ExtractUnits ()
.SortByState ()
.PublishTo (target);

47. created by
class MainClass
{
public static void Main (string[] args)
{
var ftpFolder = new FtpFolder ();
GetFilesFrom (ftpFolder)
.ExtractUnits ()
.SortByState ()
.PublishTo (target);
}
static FileList GetFilesFrom (FtpFolder ftpFolder)
{
return ftpFolder.FetchFiles();
}
}
class FtpFolder { … }
class FileList
{
private List<String> _files;
…
public Units ExtractUnits ()
{
return new Units ();
}
}
class Units
{
private List<Unit> _units;
…
public Units SortByState () { … }
public void PublishTo (ITarget target) { … }
}
• Fluent Interface
• Simple Types
• Single Responsibility
• Domain Specific
Terms
Lösung: Refactoring

48. created by
Hier kam das
Resümee

49. created by
merci
thank you
danke
dekuji
tak dank je we
xièxie
kiitos
toda
köszönöm
go raibh maith agat
grazie
dziekuje
multumesc
spacibo
hvala
gracias
tack
mauruuru
tesekkur ederim
diakuiu
a dank