Detekt rules for Android

This repository contains an opinionated set of Detekt Rules for Android projects

Getting started

1. Add this library declaration into your detekt dependencies

detekt {
    // ...
}

dependencies {
    detektPlugins "br.com.wesjon:detekt-android-rules:0.1" // Add it here
    detektPlugins "io.gitlab.arturbosch.detekt:detekt-formatting:$detekt_version"
}

2. Include a new block in your detekt.yml file

You may want to activate or deactivate rules according to your project needs.

android-rules:
  TestNameShouldFollowNamingConvention:
    active: true
    namingConvention: 'backtick' // REQUIRED: backtick, snake_case or camelCase
  ViewModelExposesState:
    active: true
    customViewModel: 'BaseViewModel,CustomViewModel' // OPTIONAL: If your application uses base/custom ViewModels

Rules

TestNameShouldFollowNamingConvention

Checks whether test names follow the name convention. This rule only applies if method is annotated with @Test

NON-compliant code

CONFIG: backtick

@Test
fun additionIsCorrect(){
    // ...
}

Compliant code

// config: backtick
@Test
fun `addition is correct`(){
    // ...
}

// config: snake_case
@Test
fun addition_is_correct(){
    // ...
}

// config: camelCase
@Test
fun additionIsCorrect(){
    // ...
}

ViewModelExposesState

MVVM has popularized the use of ViewModels in Android apps. Exposing a MutableLiveData to the View layer is an antipattern and should be avoided when using ViewModels.

Non-compliant code

class LoginViewModel: ViewModel() {
     val loginViewState = MutableLiveData<LoginViewState>()
}

Compliant code

class LoginViewModel: ViewModel() {
     private val loginViewState = MutableLiveData<LoginViewState>()
     val loginViewState: LiveData<LoginViewState> = _loginViewState
}