FluentInterfaceHandsOn
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This document discusses fluent interfaces and provides examples of how they can be implemented. It begins with an example of refactoring legacy code to use a fluent interface to improve readability. It then discusses different design patterns that can be used to implement fluent interfaces, such as method chaining, builder, and facade patterns. The document concludes that fluent interfaces can improve code readability but require additional effort and may complicate debugging.
FluentInterfaceHandsOn
- 1. Fluent Interface: Hands On Tomaš Maconko https://github.com/tmaconko/FluentInterface https://github.com/BalticAmadeus
- 2. SAD STORY • Huge domain • Legacy code • Complex tests • Mocks, fakes, stubs
- 3. 3 SAD STORY
- 4. WHATS WRONG? • Monstrous ARRANGE step • Non-readable code • Mocks • And… 4
- 5. FIRST STEP: GRAB THE MAGIC STICK! 5
- 6. THE MAGIC HAPPENS: WE REFACTORED IT! 6
- 7. 7 ALL THE SH*T WENT TO ANOTHER PLACE
- 8. BUT… WHAT NEXT? • What will happen when create more and more stuff that depend on unique data (e.g. ~3k tests)? • What about specific parameters/cases? 8
- 9. COPY-PASTE 9
- 10. SECOND STEP: GRAB THE MAGIC STICK! 10
- 11. EXTRACT CLASSES AND SPLIT THE STUFF 11
- 12. 12 THINK ABOUT PARAMETRIZATION • PrepareOrderWithClient • PrepareOrderWithClientWithoutAddress • PrepareOrderWithClientWithoutShop • PrepareOrder…
- 14. THIRD STEP: APPLY DESIGN PATTERNS! • Method chaining • Builder • Facade • Internal DSL 14
- 18. INTERNAL DSL 18 Note: Care about using the extensions. It is important to track the usage scope.
- 21. LIKE NUnit 21
- 24. WHAT IS FLUENT INTERFACE? • A flavor of API • Used with Object Oriented Programming • Enables better code readability and discoverability • Simplifies usage of complex APIs • Allows to express domain concepts more clearly 24
- 25. WHEN TO USE IT? • To hide legacy code • Third-party libraries, that may need configuration • Complex unit tests’ data arrangement • When we want code to be more readable 25
- 31. CONS: REQUIRES ADDITIONAL EFFORT AND CODE 31
- 32. CONS: DEBUGGING BECOMES MORE COMPLICATED 32
- 33. 33 CONS: BAD API CAN CAUSE DATA ERRORS
- 34. CONCLUSIONS • Fluent API can be applied at any level • Improves code readability • May not follow OOP principles • Can be used to restrict users to follow the rules of domain flow • Requires developers to think from user perspective 34
- 35. SOURCES • Domain-Specific Languages – Martin Fowler. Addison-Wesley Professional, 1 edition, 2010. • Fluent Interfaces – Erik Schierboom. Link: http://www.erikschierboom.com/2014/10/08/fluent-interfaces/ • Fluent Interface for More Readable Code. – Yunus Emre Keskin. Link: https://dzone.com/articles/fluent-interface-more-readable-0 • When To Build Fluent Interfaces for Re-Use and Clarity. – Peter Vogel. Link: https://visualstudiomagazine.com/articles/2013/11/01/when-to-build-fluent- interfaces-for-re-use-and-clarity.aspx 35
- 36. QUESTIONS? 36