Add proguard rules for R8 full mode

README.md

@@ -56,6 +56,11 @@ dependencies {
 
 </details>
 
+
+## R8 / ProGuard
+The specific rules are [already bundled](sandwich/src/main/resources/META-INF/proguard/sandwich.pro) into the JAR which can be interpreted by R8 automatically.
+
+
 ## Use Cases
 You can also check out nice use cases of this library in the repositories below:
 - [Pokedex](https://github.com/skydoves/pokedex): 🗡️ Android Pokedex using Hilt, Motion, Coroutines, Flow, Jetpack (Room, ViewModel, LiveData) based on MVVM architecture.

app/build.gradle

@@ -39,6 +39,14 @@ android {
     dataBinding true
   }
 
+  buildTypes {
+    release {
+      minifyEnabled true
+      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+      signingConfig = signingConfigs.debug
+    }
+  }
+
   // Can remove this once https://issuetracker.google.com/issues/260059413 is fixed.
   compileOptions {
     sourceCompatibility JavaVersion.VERSION_11

app/proguard-rules.pro

@@ -0,0 +1,10 @@
+# https://github.com/square/okhttp/blob/339732e3a1b78be5d792860109047f68a011b5eb/okhttp/src/jvmMain/resources/META-INF/proguard/okhttp3.pro#L11-L14
+-dontwarn okhttp3.internal.platform.**
+-dontwarn org.conscrypt.**
+-dontwarn org.bouncycastle.**
+-dontwarn org.openjsse.**
+
+# TODO: Waiting for new retrofit release to remove these rules
+-keep,allowobfuscation,allowshrinking interface retrofit2.Call
+-keep,allowobfuscation,allowshrinking class retrofit2.Response
+-keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation

sandwich/src/main/resources/META-INF/proguard/sandwich.pro

@@ -0,0 +1,2 @@
+# R8 full mode strips signatures from non-kept items.
+-keep,allowobfuscation,allowshrinking class com.skydoves.sandwich.ApiResponse