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Refactoring: Code it Clean
- 1. Refactoring: Code it clean englishninjas Ali Germiyanoglu
- 3. What is it, can we eat it? Martin Fowler “a change made to the internal structure of software to make it easier to understand and cheaper to modify without changing its observable behavior” Noun : Verb: “to restructure software by applying a series of refactorings without changing its observable behavior”
- 4. understand track the bugs do things faster Improves the Design of Software Helps you to: Why lose time, lets focus on new features!
- 5. Code review Adding a function Bug fix When shall we do it?
- 7. Apply one of the refactoring methods Check if your tests still pass Keep refactoring Fix the problem How to ?
- 8. –Kent Beck “I'm not a great programmer; I'm just a good programmer with great habits.”
- 9. Code Smell
- 15. Long Method Conditional Complexity Type Embedded in Name Feature Envy Lazy Class
- 16. Long Method Long Parameter List Conditional Complexity Type Embedded in Name Feature Envy Lazy Class
- 17. Long Method Long Parameter List Conditional Complexity Large Class Type Embedded in Name Feature Envy Lazy Class
- 18. Long Method Long Parameter List Conditional Complexity Large Class Type Embedded in Name Oddball Solutio n Feature Envy Lazy Class
- 21. MOTIVATION Mechanics Create new method Extract partial code Call newly created method
- 28. MOTIVATION Mechanics Declare final temporary variable Use it
- 34. MOTIVATION As you learn more about the problem and realize that there is an easier way to do it
- 35. MOTIVATION Mechanics Prepare your alternative algoritm Test your new algorithm Replace it
- 39. MOTIVATION Encapsulation As you become more sophisticated, you realize there is more you can encapsulate
- 40. MOTIVATION Mechanics Hide implementation details by creating extra delegate methods
- 43. –Kent Beck The list of techniques is only the beginning. It is the gate you must pass through. Without the techniques, you can't manipulate the design of running programs. With them, you still can't, but at least you can start.
- 44. MOTIVATION You have sequence of conditional tests with same result
- 51. MOTIVATION Behaviour difference according to type of object Because you like OO
- 52. MOTIVATION Mechanics Move each leg of the conditional to an overriding method in a subclass. Make the original method abstract.
- 59. MOTIVATION Method returns a value but also changes the state of the object Not cool with testing!
- 60. MOTIVATION Mechanics Just divide method into two different methods
- 62. Rename method Hide method & variables
- 63. Rename method Hide method & variables Encapsulate collection
- 64. Rename method Change value to reference Hide method & variables Encapsulate collection
- 65. Rename method Change value to reference Hide method & variables Change reference to value Encapsulate collection
- 66. Rename method Change value to reference Hide method & variables Change reference to value Encapsulate collection Remove assignments to parameters
- 67. Rename method Change value to reference Hide method & variables Change reference to value Encapsulate collection Remove assignments to parameters Remove Control Flags
- 68. Rename method Change value to reference Hide method & variables Change reference to value Encapsulate collection Remove assignments to parameters Remove Control Flags Tease Apart Inheritance
- 69. Rename method Change value to reference Hide method & variables Change reference to value Encapsulate collection Remove assignments to parameters Remove Control Flags Tease Apart Inheritance Seperate Domain from Presentation
- 70. Rename method Change value to reference Hide method & variables Change reference to value Encapsulate collection Convert procedural design to objects Remove assignments to parameters Remove Control Flags Tease Apart Inheritance Seperate Domain from Presentation
- 71. Any fool can write code that a computer can understand. Good programmers write code that humans can understand
- 72. (http://hoaxes.org/photo_database/image/the_tip_of_the_iceberg ) Tip of the iceberg (https://blog.codinghorror.com/code-smells/)Code smell Refactoring by Martin Fowler
Editor's Notes
- Scratching the surface Refactoring is at the core of TDD & Agile Same guys who builds the modern software terminologies Actually its documentation of methods they have been using for readable, testable, maintainable software Today its all about restructure the code, basic level
- Mention about the book Your definition
- quality. Improving design, improving readability, reducing bugs, all these improve quality. But doesn't all this reduce the speed of development? good design is essential for rapid software development spend time finding and fixing bugs instead of adding new function. Changes take longer as you try to understand the system and find the duplicate code
- Surekli yeni featurelar, yeni kurallar, yaz yaz yaz nereye kadar refactor olmayan kod legacy x
- - More methodological approach
- We don’t have tests! Mention about TDD vs testable code Way of thinking
- Feature Envy: Methods that make extensive use of another class may belong in another class. Consider moving this method to the class it is so envious of. Lazy Class: Classes should pull their weight. Every additional class increases the complexity of a project. If you have a class that isn't doing enough to pay for itself, can it be collapsed or combined into another class? Large Class: Large classes, like long methods, are difficult to read, understand, and troubleshoot. Does the class contain too many responsibilities? Can the large class be restructured or broken into smaller classes? Type Embedded in Name: Avoid placing types in method names; it's not only redundant, but it forces you to change the name if the type changes. Oddball Solution: There should only be one way of solving the same problem in your code. If you find an oddball solution, it could be a case of poorly duplicated code-- or it could be an argument for the adapter model, if you really need multiple solutions to the same problem.
- Think of your code, not basic examples In here What are your code smells ?
- - Does this need comment; code itself is a way of commenting
- - Multiple refactoring methods used!
- - Finish / Continue ?
- - Simplification, readability, testability
- - let the caller call multiple callees
- - Swift access methods internal, private fileprivate public open
- Naming conventions, enums, classes Method functionality
- Users transactions, would not know if transaction list just exposed Instead you can create add/RemoveTransaction to User object
- Swift function parameters in/out when to use copy by value or copy by reference - Data types such as int, date value its can be copied its ok, But what if I copy a student & want to change her grade !, Will all system be affected ?
- Swift function parameters in/out when to use copy by value or copy by reference
- Similar to reference/value types
- - flag programming
- Design refactor nothing like here!
- Design refactor nothing like here!
- Last 3 methods are ‘Design Refactor’; nothing like here!