android-proguard-setup

• Android project with Gradle
• Kotlin DSL (build.gradle.kts)

| Input | Required | Default | Description |

|-------|----------|---------|-------------|

| project_path | Yes | . | Android project root |

Step 1: Create ProGuard Rules File

Create or update app/proguard-rules.pro with safe defaults:

```bash

cat > app/proguard-rules.pro << 'EOF'

# Add project specific ProGuard rules here.

# By default, the flags in this file are appended to flags specified

# in the Android SDK.

# Keep line numbers for debugging stack traces

-keepattributes SourceFile,LineNumberTable

# Hide the original source file name

-renamesourcefileattribute SourceFile

# Keep data classes and their fields

-keepclassmembers class * {

@kotlinx.serialization.SerialName ;

}

# Keep Parcelables

-keepclassmembers class * implements android.os.Parcelable {

public static final android.os.Parcelable$Creator *;

}

# Keep custom views

-keep public class * extends android.view.View {

public (android.content.Context);

public (android.content.Context, android.util.AttributeSet);

public (android.content.Context, android.util.AttributeSet, int);

}

# Keep native methods

-keepclasseswithmembernames class * {

native ;

}

EOF

```

Note: If proguard-rules.pro already exists, ask the user if they want to:

• Replace with safe defaults
• Append safe defaults to existing rules
• Keep existing rules as-is

Step 2: Enable Minification in build.gradle.kts

Update app/build.gradle.kts to enable ProGuard/R8:

```kotlin

android {

// ... existing config ...

buildTypes {

release {

isMinifyEnabled = true

isShrinkResources = true

proguardFiles(

getDefaultProguardFile("proguard-android-optimize.txt"),

"proguard-rules.pro"

)

}

}

}

```

Detection logic:

• Check if buildTypes.release already exists
• Check if isMinifyEnabled is already set
• Preserve existing proguardFiles if present, append if needed

MANDATORY: Run these commands:

```bash

# Verify ProGuard rules file exists

test -f app/proguard-rules.pro && echo "✓ ProGuard rules exist"

# Verify minification is enabled

grep "isMinifyEnabled = true" app/build.gradle.kts && echo "✓ Minification enabled"

# Verify resource shrinking is enabled

grep "isShrinkResources = true" app/build.gradle.kts && echo "✓ Resource shrinking enabled"

```

Expected output:

• ✓ ProGuard rules exist
• ✓ Minification enabled
• ✓ Resource shrinking enabled

| Output | Location | Description |

|--------|----------|-------------|

| ProGuard rules | app/proguard-rules.pro | Safe default keep rules |

| Build config | app/build.gradle.kts | Minification enabled |

"Build fails with ProGuard error"

Cause: ProGuard removed required classes

Fix: Add keep rules for the failing classes to proguard-rules.pro

"App crashes on release but not debug"

Cause: ProGuard obfuscated code that uses reflection

Fix: Add keep rules for classes used via reflection

Add these rules based on your project dependencies:

Retrofit/OkHttp

```proguard

-keepattributes Signature

-keepattributes Annotation

-keep class okhttp3.* { ; }

-keep interface okhttp3.* { ; }

-dontwarn okhttp3.**

-keepattributes Signature, InnerClasses, EnclosingMethod

-keepclassmembers,allowshrinking,allowobfuscation interface * {

@retrofit2.http.* ;

}

```

Gson

```proguard

-keepattributes Signature

-keepattributes Annotation

-keep class com.google.gson.* { ; }

-keep class * implements com.google.gson.TypeAdapterFactory

-keep class * implements com.google.gson.JsonSerializer

-keep class * implements com.google.gson.JsonDeserializer

-keepclassmembers,allowobfuscation class * {

@com.google.gson.annotations.SerializedName ;

}

```

Kotlin Serialization

```proguard

-keepattributes Annotation, InnerClasses

-dontnote kotlinx.serialization.AnnotationsKt

-keepclassmembers class kotlinx.serialization.json.** {

*** Companion;

}

```

Health Connect

```proguard

-keep class androidx.health.connect.client.* { ; }

-keep class androidx.health.platform.client.* { ; }

```

Room

```proguard

-keep class * extends androidx.room.RoomDatabase

-keep @androidx.room.Entity class *

```

Important: Test libraries should NEVER be in release builds. They are androidTestImplementation only.

If you need to run instrumented tests on release builds (e.g., to verify signing), use a separate test ProGuard file:

Step 1: Create app/proguard-rules-androidTest.pro:

```proguard

# Keep EVERYTHING in test APK - we only care about signing, not size

-dontobfuscate

-dontoptimize

-dontshrink

-keep class * { ; }

```

Step 2: Update app/build.gradle.kts:

```kotlin

android {

buildTypes {

release {

isMinifyEnabled = true

signingConfig = signingConfigs.getByName("release")

proguardFiles(

getDefaultProguardFile("proguard-android-optimize.txt"),

"proguard-rules.pro"

)

// Keep-all rules for test APK only

testProguardFiles("proguard-rules-androidTest.pro")

}

}

testBuildType = "release"

}

```

Result:

• App APK: Minified with release key ✅
• Test APK: Not minified, signed with release key ✅
• Both have matching signatures for instrumentation ✅

• [ ] app/proguard-rules.pro exists with safe defaults
• [ ] isMinifyEnabled = true in app/build.gradle.kts
• [ ] isShrinkResources = true in app/build.gradle.kts
• [ ] ProGuard rules syntax is valid