[#23] Minify release builds

README.md

@@ -36,5 +36,6 @@ If you plan to fork the project to create a new app of your own, please make the
 1. Test coverage for Compose code will be low, due to [known limitations](https://github.com/jacoco/jacoco/issues/1208) in the interaction between Compose and Jacoco.
 1. Adding the `espresso-contrib` dependency will cause builds to fail, due to conflicting classes.  This is a [known issue](https://github.com/zcash/zcash-android-wallet-sdk/issues/306) with the Zcash Android SDK.
 1. Android Studio will warn about the Gradle checksum.  This is a [known issue](https://github.com/gradle/gradle/issues/9361) and can be safely ignored.
+1. [#96](https://github.com/zcash/secant-android-wallet/issues/96) - Release builds print some R8 warnings which can be safely ignored.
 1. During app first launch, the following exception starting with `AndroidKeysetManager: keyset not found, will generate a new one` is printed twice.  This exception is not an error, and the code is not being invoked twice.
 1. The task `ktlintFormat` fails on Java 16 or greater.  As a workaround, the task is run under Java 11.  This requires that JDK 11 be installed, even if a newer JDK is also installed.  While this is configured to use the Java toolchain API, [toolchain support for Java 11 does not work on Apple Silicon](https://github.com/gradle/gradle/issues/19140).  [Azul Zulu](https://www.azul.com/downloads/?os=macos&architecture=arm-64-bit&package=jdk) does offer JDK 11, which must be installed manually to run this task from the command line on Apple Silicon.

app/build.gradle.kts

@@ -43,11 +43,10 @@ android {
     buildTypes {
         getByName("release").apply {
             isMinifyEnabled = project.property("IS_MINIFY_ENABLED").toString().toBoolean()
-            proguardFiles.addAll(
-                listOf(
-                    getDefaultProguardFile("proguard-android-optimize.txt"),
-                    File("proguard-project.txt")
-                )
+            isShrinkResources = project.property("IS_MINIFY_ENABLED").toString().toBoolean()
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-project.txt"
             )
         }
     }
@@ -81,6 +80,32 @@ android {
         jvmTarget = libs.versions.java.get()
         allWarningsAsErrors = project.property("IS_TREAT_WARNINGS_AS_ERRORS").toString().toBoolean()
     }
+
+    packagingOptions {
+        resources.excludes.addAll(
+            listOf(
+                "**/*.kotlin_metadata",
+                ".readme",
+                "build-data.properties",
+                "META-INF/*.kotlin_module",
+                "META-INF/android.arch**",
+                "META-INF/androidx**",
+                "META-INF/com.android**",
+                "META-INF/com.google.android.material_material.version",
+                "META-INF/com.google.dagger_dagger.version",
+                "META-INF/services/org.jetbrains.kotlin.compiler.plugin.CommandLineProcessor",
+                "META-INF/services/org.jetbrains.kotlin.compiler.plugin.ComponentRegistrar",
+                "META-INF/services/org.jetbrains.kotlin.diagnostics.rendering.DefaultErrorMessages\$Extension",
+                "firebase-**.properties",
+                "kotlin/**",
+                "play-services-**.properties",
+                "protolite-well-known-types.properties",
+                "transport-api.properties",
+                "transport-backend-cct.properties",
+                "transport-runtime.properties",
+            )
+        )
+    }
 }
 
 dependencies {

app/proguard-project.txt

@@ -1,9 +1,17 @@
-# This improves obfuscation.
--repackageclasses 'cash.z.ecc.android'
+# Commenting this out would improve obfuscation. The wallet is already open source so obfuscation doesn't provide much benefit
+# and makes analyzing the release build of the app more difficult.
+-dontobfuscate
 
 # Ensure that stacktraces are reversible.
 -renamesourcefileattribute SourceFile
 -keepattributes SourceFile,LineNumberTable
 
 # Generate the combined proguard configuration for debugging.
--printconfiguration build/outputs/proguard-config.txt
+-printconfiguration build/outputs/proguard-config.txt
+
+-dontwarn javax.naming.NamingEnumeration
+-dontwarn javax.naming.NamingException
+-dontwarn javax.naming.directory.Attribute
+-dontwarn javax.naming.directory.Attributes
+-dontwarn javax.naming.directory.DirContext
+-dontwarn javax.naming.directory.InitialDirContext

docs/Setup.md

@@ -10,9 +10,8 @@ To get set up for development, there are several steps that you need to go throu
 
 Start by making sure the command line with Gradle works first, because **all the Android Studio run configurations use Gradle internally.**  The run configurations are not magic—they map directly to command line invocations with different arguments.
 
-1. Install Java
+1. Configure Java
     1. Java 16 is currently recommended. Java 11 is the minimum requirement for Android Studio.
-    1. To simplify installation, use [Oracle's JDK](https://www.oracle.com/java/technologies/javase-jdk16-downloads.html) installer that will place the Java installation in the right place
 1. Install Android Studio and the Android SDK
     1. Download the [Android Studio Bumblebee Canary](https://developer.android.com/studio/preview) (we're using the Canary version, due to its improved integration with Jetpack Compose)
     1. TODO: Fill in step-by-step instructions for setting up a new environment and installing the Android SDK from within Android Studio