From c30a49e8415a7adaa680d1d6a788d22e08e8809b Mon Sep 17 00:00:00 2001
From: Jacob Hagstedt <jacob.hagstedt@gmail.com>
Date: Sun, 18 Oct 2026 21:32:15 +0200
Subject: [PATCH] Android: R8 shrinking, optimisation and resource shrinking
 for the release build

isMinifyEnabled and isShrinkResources on the release build type with
proguard-android-optimize.txt and an app proguard-rules.pro that adds no rules:
the libraries' consumer rules cover kotlinx.serialization, Room 3, Hilt, Ktor,
WorkManager (worker class names kept) and Firebase. Debug is unchanged.
Signed release APK 43 356 272 -> 11 019 453 bytes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TQd3pEP9UeN2uifbHknQ7B
---
 android/app/build.gradle.kts   | 5 +++++
 android/app/proguard-rules.pro | 3 +++
 2 files changed, 8 insertions(+)
 create mode 100644 android/app/proguard-rules.pro

diff --git a/android/app/build.gradle.kts b/android/app/build.gradle.kts
index fff7ac8..7293162 100644
--- a/android/app/build.gradle.kts
+++ b/android/app/build.gradle.kts
@@ -48,6 +48,11 @@ android {
         }
         release {
             if (releaseStoreFile != null) signingConfig = signingConfigs.getByName("release")
+            // SPEC §10.6: R8 shrinks, optimises and obfuscates the release APK; the libraries' consumer rules plus
+            // proguard-rules.pro. publish-apk.sh keeps build/outputs/mapping/release/mapping.txt next to the APK.
+            isMinifyEnabled = true
+            isShrinkResources = true
+            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
         }
     }
     sourceSets {
diff --git a/android/app/proguard-rules.pro b/android/app/proguard-rules.pro
new file mode 100644
index 0000000..ef43999
--- /dev/null
+++ b/android/app/proguard-rules.pro
@@ -0,0 +1,3 @@
+# R8 rules for the release build of :app (SPEC §10.6). The libraries in use (kotlinx.serialization, Room 3, Hilt,
+# Ktor, OkHttp, WorkManager, Firebase messaging, Coil) ship their own consumer rules; add a rule here only for a
+# failure that was seen and with the reason beside it.