Score the Tendulkar Test Coverage @GopalAkshintala

Gopal S Akshintala Engineering Lead, Salesforce Community Day 2022 September 10th, 2022 T-Hub, Hyderabad @GopalAkshintala overfullstack.ga

Sachin Tendulkar holds the record for highest number of dismissals in the 90s (28 times)🏏

@GopalAkshintala

Why Unit Test ? 🧪 @GopalAkshintala

Why Unit Test? @GopalAkshintala Find Bugs Statement Coverage Behaviour documentation in form of code Strive for behaviour coverage NOT Statement coverage

What makes Unit Testing Di ffi cult? 😓 @GopalAkshintala Code Smells void methods static methods that are not static Bad Design Legacy Code interactions

We have the Hammer! OOps! @GopalAkshintala

The Unstoppable Hammer! OOps! @GopalAkshintala Suppress this and super constructor static init blocks Stub private methods static methods final methods Constructors Mock final classes

The PowerMock Rocky! @GopalAkshintala OOps! 100%

The Dark Powers 👹 Synthetic coverage is dangerous PowerMock is a new framework to learn Involves a lot of Setup and trail-and-error to get it right Tests written with PowerMock are brittle and difficult to Maintain It’s not Transparent OOps! @GopalAkshintala

@GopalAkshintala

PowerMock is a 💊 Painkiller @GopalAkshintala

But! Why is PowerMock Invasive? @GopalAkshintala

@GopalAkshintala powermock.github.io

PowerMock Compatibility Incompatible with JUnit 5 JUnit 5 was release 5 years ago Incompatible with Latest Mockito Latest Mockito: 4.20 Compatible version: 3.12 Not fully compatible with Java 11 OOps! @GopalAkshintala

But do I need Unit Tests at all? Can’t I get Coverage with Integration Tests!? 🤷 @GopalAkshintala

@GopalAkshintala ITests Vs UTests

@GopalAkshintala Use-Case Diagram

@GopalAkshintala ITests Vs UTests Use-case: How customer uses ITests should test Features Use-cases : Features : Components 1 Feature: Reflects software Functionality UTests should test Component Behaviour N N

@GopalAkshintala ITests Vs UTests Traceability - How well a given test can precisely trace/pinpoint the cause of failure when it fails Productivity - Writing, Executing and Maintaining effort

The Redemption 🍕 🥗 @GopalAkshintala

@GopalAkshintala Code Smells 🐽

@GopalAkshintala Code Smells 🐽 Avoid void Methods

@GopalAkshintala Code Smells 🐽 Are static methods bad for Unit testing?

@GopalAkshintala Pure Vs Impure Pure Logic Impure Side-Effects REST I/O DB I/O Events • Data-in 
 Data-out • Referentially Transparent

@GopalAkshintala Impure static void add(int a, int b) { System.out.println(a + b); }

@GopalAkshintala Pure static int add(int a, int b) { return a + b; }

@GopalAkshintala Impure Pure static void add(int a, int b, Consumer consumer) { consumer.accept(a + b); } / / Function call in Prod add(1, 2, System.out :: println); / / Function call in Test add(1, 2, result -> assertEquals(3, result));

@GopalAkshintala Bad Design

@GopalAkshintala Bad Design OOP P 💩

@GopalAkshintala 👨💼 🙉 Domain Logic DB layer Prod Test

@GopalAkshintala Design for Tests A Unit Test is the First client for your Component

@GopalAkshintala Test in Isolation Mock Dependencies NOT Statements

@GopalAkshintala Test in Isolation Inject your Dependencies 💉

@GopalAkshintala Legacy Dependencies 🗿 🗿

@GopalAkshintala Legacy Dependencies If you interact with a
 Legacy component, Your component Instantly turns Legacy!

@GopalAkshintala Legacy Dependencies If you “Directly” interact with a
 Legacy component, Your component Instantly turns Legacy!

@GopalAkshintala Ports & Adapters Domain Adapters

@GopalAkshintala 👨💼 🙉 Domain Logic DB layer Prod Test

@GopalAkshintala Port 👨💼 🐵 Isolated Domain Logic DB layer Prod Adapter Fake Adapter Prod Test

@GopalAkshintala Black box Unit Testing Unit Test ! = Test Internals Unit Test == E2E test for the Component

@GopalAkshintala Anti-Patterns (digitaltapestry.net) https://confluence.internal.salesforce.com/display/TESTSFDC/ Unit+Testing+Best+Practices https://confluence.internal.salesforce.com/display/TESTSFDC/ Unit+Test+Recipes%3A+How+to+Write+High-Quality+Tests Explanation how proxy based Mock Frameworks work Write tests. Not too many. Mostly integration. (kentcdodds.com) Testing of Microservices - Spotify Engineering : Spotify Engineering (atspotify.com) On the Diverse And Fantastical Shapes of Testing (martinfowler.com) ongoing by Tim Bray · Testing in the Twenties (tbray.org) Resources

No one gives you Change, you need to bring Change - Ramulu, Bus conductor #dadJoke

@GopalAkshintala github.com/overfullstack/sttc-demo { } speakerdeck.com/gopalakshintala/ score-the-tendulkar-test-coverage

@GopalAkshintala 🐵