Ensure release variants build successfully without any setup

.travis.yml

@@ -22,8 +22,10 @@ android:
     # https://github.com/travis-ci/travis-ci/issues/6040#issuecomment-219367943
     - tools
     - tools
-before_script: mv library/google-services.json app/google-services.json
-script: ./gradlew clean assembleDebug check
+before_script:
+  - cp library/google-services.json app/google-services.json
+  - cp library/google-services.json proguard-tests/google-services.json
+script: ./gradlew clean assembleDebug proguard-tests:build check
 after_success: ./scripts/artifactory.sh
 after_failure:
   # tests

auth/auth-proguard.pro

@@ -1,7 +1,6 @@
 # Twitter and Facebook are optional
--dontwarn com.twitter.**
 -dontwarn com.facebook.**
--dontwarn com.firebase.ui.auth.provider.**
+-dontwarn com.twitter.**
 
 # Don't note a bunch of dynamically referenced classes
 -dontnote com.google.**
@@ -16,5 +15,6 @@
 
 # Retrofit config
 -dontnote retrofit2.Platform
--dontwarn retrofit2.Platform$Java8
+-dontwarn retrofit2.** # Also keeps Twitter at bay as long as they keep using Retrofit
+-dontwarn okio.**
 -keepattributes Exceptions

proguard-tests/build.gradle

@@ -0,0 +1,39 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion compileSdk
+
+    defaultConfig {
+        applicationId "com.firebase.uidemo"
+        minSdkVersion 16
+        targetSdkVersion targetSdk
+        versionCode 1
+        versionName version
+    }
+
+    buildTypes {
+        release {
+            // For the purposes of the sample, allow testing of a proguarded release build
+            // using the debug key
+            signingConfig signingConfigs.debug
+
+            postprocessing {
+                removeUnusedCode true
+                removeUnusedResources true
+                obfuscate true
+                optimizeCode true
+            }
+        }
+    }
+}
+
+dependencies {
+    implementation "com.google.firebase:firebase-core:$firebaseVersion"
+
+    implementation project(path: ':auth')
+    implementation project(path: ':firestore')
+    implementation project(path: ':database')
+    implementation project(path: ':storage')
+}
+
+apply plugin: 'com.google.gms.google-services'

proguard-tests/src/main/AndroidManifest.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest package="com.firebase.uidemo"/>

settings.gradle

@@ -1,2 +1,2 @@
 include ':app', ':library', ':database', ':auth', ':storage', ':firestore', ':common',
-        ':internal:lint', ':internal:lintchecks'
+        'proguard-tests', ':internal:lint', ':internal:lintchecks'