BillionBeers

This is a multi-module Android application that showcases modern architecture and testing practices. It follows Clean Architecture principles and uses MVVM for the presentation layer.

This app follows the Clean Architecture and uses MVVM architecture for the presentation layer. The app uses Kotlin DSL for dependency management and Version Catalog to manage library versions.

The app's tech stack is: Jetpack Compose, StateFlow, Room, ViewModels, Hilt, Coroutines, Jetpack Navigation and safe args, Retrofit, okHttp, GSON, Material Design, webmockserver, mockk, junit4, Strikt, Espresso.

You can find the app in google play store (https://play.google.com/store/apps/details?id=com.simtop.billionbeers&hl=es&gl=US). Any download and 5 star is greatly appreciated

For UI Testing I used the Robot Pattern.

Code Quality & Reports

This project uses several tools to ensure code quality and consistency.

1. Formatting (Spotless & ktfmt)

We use Spotless with ktfmt to enforce Google's Kotlin style guide.

Check formatting: ./gradlew spotlessCheck
Apply formatting: ./gradlew spotlessApply (Run this before committing!)

2. Static Analysis (Detekt)

We use Detekt to find code smells and complexity issues.

Run analysis: ./gradlew detekt
Reports: Found in build/reports/detekt/ for each module (e.g., app/build/reports/detekt/detekt.html).

3. Code Coverage (Jacoco)

We use Jacoco to measure test coverage.

Generate reports: ./gradlew jacocoTestReport
Reports: Found in build/reports/jacoco/jacocoTestReport/html/index.html for each module (e.g., core-common/build/reports/jacoco/jacocoTestReport/html/index.html).

4. Screenshot Testing (Paparazzi)

We use Paparazzi for screenshot testing our Compose UI.

Record specific module: ./gradlew :feature:beerdetail:recordPaparazziDebug
Verify specific module: ./gradlew :feature:beerdetail:verifyPaparazziDebug
Record all modules: ./gradlew recordPaparazziDebug
Verify all modules: ./gradlew verifyPaparazziDebug
Clean and record: ./gradlew cleanRecordPaparazziDebug
Reports: Found in build/reports/paparazzi/ for each module.

5. Performance Measurement & Profiling

This project includes a robust system for measuring and improving performance.

A. Gradle Build Profiling (Build Speed)

We use Gradle Profiler to automate build measurements.

Requirement: brew install gradle-profiler

Run benchmark:

gradle-profiler --benchmark --scenario-file ./benchmark.scenarios incremental_build

Scenarios: Defined in benchmark.scenarios (Clean build, Incremental, etc.).

B. Microbenchmarking (Code Logic)

Measure the performance of CPU-bound logic (e.g., BeersMapper).

Run: ./gradlew :benchmark:microbenchmark:connectedCheck
Reports: benchmark/microbenchmark/build/reports/androidTests/connected/release/index.html

C. Macrobenchmarking (App Startup & Jank)

Measure high-level user experience like App Startup and Scrolling.

Run: ./gradlew :benchmark:macrobenchmark:connectedCheck
Reports: benchmark/macrobenchmark/build/reports/androidTests/connected/debug/index.html
Notes:
- Uses a dedicated benchmark build type (minified but debug-signed).
- Macrobenchmarks requires a physical device for accurate frame timing results.
- Suppression rules are enabled in gradle.properties for local emulator testing.

D. Interpreting Results

Micro: Focus on Median time and Allocations (aim for 0 allocs in hot loops).
Macro: Aim for Cold Startup < 500ms and Frame Overrun 0ms (perfect 60fps).

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated and it will be a pleasure to collaborate with you..

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!