Design Guideline is Testability ## JODY HAGINS ## +24 ## The Most Important Design Guideline is Testability ## JODY HAGINS ## CppCon 2024 The Most Important Design Guideline is Testability Jody Hagins jhagins@dev CppCon 2024 The Most Important Design Guideline is Testability Jody Hagins jhagins@dev.null ## CppCon 2024 The Most Important Design Guideline is Testability Jody Hagins jhagins@maystreet.com coachhagins@gmail Copyrighted material, all rights reserved. Slide 2 ## The Most Important API Design Guideline? ## TESTABILITY Copyrighted material, all rights reserved. Slide 2 ## Why is Testing Important? ![Image](/u

Enhances Reusability Components become more generic, thus can be better reused. ## I mproves Testability Easier to test components in isolation. Hiding your Implementation Details is Not So Simple Hiding 45_1.jpg)  Testability and API Design John Pavan · Aram Chung · Lukas Zhao And: it's context specific! ## Yes, it's will not cover it here. Mentioned also by Jody Hagins in “The Most Important Design Guideline is Testability” on his Monday here at CppCon 2024. See also: https://stackoverflow.com/a/11622314/2085626 https://blog

Design Design Guidelines Design for Readability Design for Change and Extension Design for Testability Implementation Guidelines Resource Management ## Back to Basics: Class Design (Part 2) Implementation Design Design Guidelines Design for Readability Design for Change and Extension Design for Testability Implementation Guidelines Resource Management ## Back to Basics: Class Design (Part 2) Implementation Design Design Guidelines Design for Readability Design for Change and Extension Design for Testability Implementation Guidelines Resource Management ## Back to Basics: Class Design (Part 2) Implementation

Design Design Guidelines Design for Readability Design for Change and Extension Design for Testability Implementation Guidelines Resource Management ## Back to Basics: Class Design (Part 2) Implementation Design Design Guidelines Design for Readability Design for Change and Extension Design for Testability Implementation Guidelines Resource Management ## Back to Basics: Class Design (Part 2) ## I Design Design Guidelines Design for Readability Design for Change and Extension Design for Testability Implementation Guidelines Resource Management ## Back to Basics: Class Design (Part 2) Implementation

reasoning: The code can be understood just by looking at that portion and a limited scope around it ☐ testability: Testing pure functions is trivial ## Pure Functions • A pure function is a function that ☐ is reasoning: The code can be understood just by looking at that portion and a limited scope around it ☐ testability: Testing pure functions is trivial • Practically, pure functions do not: o contain state (static reasoning: The code can be understood just by looking at that portion and a limited scope around it ☐ testability: Testing pure functions is trivial • Practically, pure functions do not: ☐ contain state (static

Notification ## MVVM: MODEL-VIEW-VIEWMODEL THE GOOD • Reactive UI data binding • Increased testability! • First viable contender to MVC (within iOS) • Post-MVC movement on iOS primarily started by classes • Difficult to onboard engineers ## GRAPH OF ARCHITECTURE OVER-SIMPLIFIED FILES AND TESTABILITY COMPLEXITY ## HOW DO WE DECIDE ON WHICH TO ADOPT? ## OUR PRODUCT PUNTERS APP • Consumer focused Backend For Frontend (BFF) server architecture ## CHOOSING AN ARCHITECTURE ## REQUIREMENTS • Testability • Code reusability • Easy to onboard • Modular • Expandable • Compatible ## PRINCIPLES •

## Unit Testing is a Big Topic • Jody Hagins (today): The Most Important Design Guideline is Testability • Greg Law and Mike Shah (tomorrow): Back To Basics, Debugging and Testing • Chip Hogg (Wednesday) SOLID • Testability • DRY … ## Process: Design ## Good Design (new) • Simplicity (small functions, Single Responsibility Rule) • Encapsulation and loose coupling SOLID • DRY Testability ## Third

Using various DI methods to achieve functionality swapping / instrumentation for flexibility and testability ☐ Primarily unit testing - Focus on strategies / How to think to achieve DI in the real world class/function independent of its underlying dependencies 3. Improves the reusability – and so testability - of code. 4. Better long term maintainability of code. Encyclopedia Muldoonica ## Testing without • Poorly formed code needs many tricks for DI • Improves the flexibility/reusability – and so testability - of a system • Better long term maintainability of code ## Dependency Injection Revelation ##

alt=‘OCR图片’/> #1 Building Tantan Backend Goals Clean Code Simplicity, Readability, Maintainability, Testability Development Efficiency Ease of Development & Deployment Scalability Vertical & Horizontal Performant Time Make iterations or CI/CD easier (bug fixes etc.) Code Quality Readability Maintainability Testability Continuous Integration Automatic Testing Henry Ren, 4 years ago | 1 author (Henry Ren) type Dispatcher

Laravel provides several opportunities to use the service container to increase the flexibility and testability of your application. One primary example is when resolving controllers. All controllers are resolved the IoC container, providing the benefit of a terse, expressive syntax while maintaining more testability and flexibility than traditional static methods. Occasionally, You may wish to create your own Facades Unit testing is an important aspect of why facades work the way that they do. In fact, testability is the primary reason for facades to even exist. For more information, check out the mocking facades