Android R8 not obfuscating class names

Question

I have been researching this for the past few hours without any luck. Class names are not obfuscated no matter what. These are just regular classes, not Activities, Services, or something else which is also in Android Manifest (I know those don't get obfuscated). What am I missing here?

Android Gradle Plugin version: 4.0.0
Gradle version: 6.1.1
Android Studio version: 4.0

With these versions, R8 should be enabled by default. Here is my buildType config:

buildTypes {
    release {
        //useProguard false // even tried this without luck
        minifyEnabled true
        shrinkResources true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        signingConfig signingConfigs.release
    }
}

Here is my proguard-rules.pro

-ignorewarnings

# --- Glide ---
-keep public class * implements com.bumptech.glide.module.GlideModule
-keep public class * extends com.bumptech.glide.module.AppGlideModule
-keep public enum com.bumptech.glide.load.ImageHeaderParser$** {
  **[] $VALUES;
  public *;
}

# --- Billing library ---
-keep class com.android.vending.billing.**

# --- Retrofit2 ---
# Retrofit does reflection on generic parameters. InnerClasses is required to use Signature and
# EnclosingMethod is required to use InnerClasses.
-keepattributes Signature, InnerClasses, EnclosingMethod

# Retrofit does reflection on method and parameter annotations.
-keepattributes RuntimeVisibleAnnotations, RuntimeVisibleParameterAnnotations

# Retain service method parameters when optimizing.
-keepclassmembers,allowshrinking,allowobfuscation interface * {
    @retrofit2.http.* <methods>;
}

# Ignore annotation used for build tooling.
-dontwarn org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement

# Animal Sniffer compileOnly dependency to ensure APIs are compatible with older versions of Java.
-dontwarn org.codehaus.mojo.animal_sniffer.*

# Ignore JSR 305 annotations for embedding nullability information.
-dontwarn javax.annotation.**

# With R8 full mode, it sees no subtypes of Retrofit interfaces since they are created with a Proxy
# and replaces all potential values with null. Explicitly keeping the interfaces prevents this.
-if interface * { @retrofit2.http.* <methods>; }
-keep,allowobfuscation interface <1>

# --- TwitterKit ---
#Picasso Proguard Config https://github.com/square/picasso
-dontwarn com.squareup.okhttp.**

# --- GSON ---
# Gson uses generic type information stored in a class file when working with fields. Proguard
# removes such information by default, so configure it to keep all of it.
-keepattributes Signature

# For using GSON @Expose annotation
-keepattributes *Annotation*

# Gson specific classes
-dontwarn sun.misc.**
#-keep class com.google.gson.stream.** { *; }

# Application classes that will be serialized/deserialized over Gson
-keep class com.google.gson.examples.android.model.** { <fields>; }

# Prevent proguard from stripping interface information from TypeAdapter, TypeAdapterFactory,
# JsonSerializer, JsonDeserializer instances (so they can be used in @JsonAdapter)
-keep class * implements com.google.gson.TypeAdapter
-keep class * implements com.google.gson.TypeAdapterFactory
-keep class * implements com.google.gson.JsonSerializer
-keep class * implements com.google.gson.JsonDeserializer

# Prevent R8 from leaving Data object members always null
-keepclassmembers,allowobfuscation class * {
  @com.google.gson.annotations.SerializedName <fields>;
}

# --- SciChart ---
# ignore warnings and save classes required for syntax highlighting
-dontwarn java.awt.**
-dontwarn javax.swing.**
-dontwarn syntaxhighlight.**

-keep public class java.awt.** { *; }
-keep public class javax.swing.** { *; }
-keep public class syntaxhighlight.** { *; }
-keep public class prettify.** { *; }

# need to keep these classes and their methods because they are used by resampling code
-keep public class com.scichart.core.model.DoubleValues { *; }
-keep public class com.scichart.core.model.FloatValues { *; }
-keep public class com.scichart.core.model.IntegerValues { *; }
-keep public class com.scichart.data.model.Point2DSeries { *; }

# repack obfuscated classes into single package so it would be hard to find their originall package
-repackageclasses ''
-allowaccessmodification

Similar questions which I checked but didn't offer any solutions to this:

• Android studio 3.4.2 R8 obfuscator does not obfuscate class names, but only java code inside
• Class no longer obfuscated after upgrading to Android Gradle plugin 3.4.0
• Android/java: Transition / Migration from ProGuard to R8?

Answer 1

As per WorkManager's proguard file, it is expected that all classes that extend ListenableWorker (and its subclasses, such as Worker) are kept. This is because the name of the class is the unique key in WorkManager's internal database.