minifyEnabled on Android: Test the Release Variant You Actually Ship

Configure the intended build type

A Kotlin DSL example is:

android {
    buildTypes {
        release {
            isMinifyEnabled = true
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
        }
    }
}

This is a module fragment, not a complete build file. Groovy DSL uses different assignment syntax. Follow the current R8 guide for your plugin version.

Check the selected variant

A product flavor combined with a build type creates the final variant. A test of debug says little about productionRelease when signing, endpoints, resources and optimization differ.

Record the exact task, artifact path, application ID and version code. The build-variant documentation helps trace which configuration produced an artifact.

Test code reached indirectly

Prioritize reflective construction, JSON serialization, dependency injection, JNI callbacks, WebView bridges and code loaded by class name. Static analysis may not infer those relationships without correct rules.

Do not solve every failure with -keep class ** { *; }. That effectively opts large parts of the program out of useful optimization and obscures the real contract.

Separate missing code from wrong configuration

Not every release-only bug is caused by R8. Temporarily toggling optimization can narrow the problem, but the final fix should address the actual cause.

Validate the shipped artifact

Install the optimized, correctly signed build on representative devices, exercise critical paths and verify a deobfuscated test crash. APKLint can help inspect the resulting package and obfuscation signals; it cannot prove that dynamically accessed features survived.