[#1435] Eliminate logging with Proguard

- Closes #1435
- Changelog update

CHANGELOG.md

@@ -7,6 +7,7 @@ and this library adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Changed
+- The SDK components no longer contain logging statements in the release build
 - Gradle 8.7
 - Android Gradle Plugin 8.3.0
 - Kotlin 1.9.23

sdk-lib/proguard-consumer.txt

@@ -0,0 +1,9 @@
+# Strip out log messages
+-assumenosideeffects public class cash.z.ecc.android.sdk.internal.Twig {
+    public static *** verbose(...);
+    public static *** debug(...);
+    public static *** info(...);
+    public static *** warn(...);
+    public static *** error(...);
+    public static *** assertLoggingStripped();
+}

sdk-lib/src/main/java/cash/z/ecc/android/sdk/Synchronizer.kt

@@ -571,6 +571,8 @@ interface Synchronizer {
 
             validateAlias(alias)
 
+            validateLogging()
+
             val saplingParamTool = SaplingParamTool.new(applicationContext)
 
             val loadedCheckpoint =
@@ -739,3 +741,10 @@ private fun validateAlias(alias: String) {
             "characters and only contain letters, digits, hyphens, and underscores."
     }
 }
+
+private fun validateLogging() {
+    if (!BuildConfig.DEBUG) {
+        // In release builds, logs should be stripped by R8 rules
+        Twig.assertLoggingStripped()
+    }
+}