ProGuard: require obfuscation be enabled explicitly (#2384)

Author: AlexeyTsvetkov

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/dsl/ProguardSettings.kt

@@ -21,4 +21,5 @@ abstract class ProguardSettings @Inject constructor(
     val maxHeapSize: Property<String?> = objects.nullableProperty()
     val configurationFiles: ConfigurableFileCollection = objects.fileCollection()
     val isEnabled: Property<Boolean> = objects.notNullProperty(false)
+    val obfuscate: Property<Boolean> = objects.notNullProperty(false)
 }

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/internal/configureJvmApplication.kt

@@ -242,6 +242,15 @@ private fun JvmApplicationContext.configureProguardTask(
     mainClass.set(app.mainClass)
     proguardVersion.set(settings.version)
     configurationFiles.from(settings.configurationFiles)
+    // ProGuard uses -dontobfuscate option to turn off obfuscation, which is enabled by default
+    // We want to disable obfuscation by default, because often
+    // it is not needed, but makes troubleshooting much harder.
+    // If obfuscation is turned off by default,
+    // enabling (`isObfuscationEnabled.set(true)`) seems much better,
+    // than disabling obfuscation disabling (`dontObfuscate.set(false)`).
+    // That's why a task property is follows ProGuard design,
+    // when our DSL does the opposite.
+    dontobfuscate.set(settings.obfuscate.map { !it })
 
     dependsOn(unpackDefaultResources)
     defaultComposeRulesFile.set(unpackDefaultResources.flatMap { it.resources.defaultComposeProguardRules })

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/tasks/AbstractProguardTask.kt

@@ -40,6 +40,10 @@ abstract class AbstractProguardTask : AbstractComposeDesktopTask() {
     @get:InputFiles
     val configurationFiles: ConfigurableFileCollection = objects.fileCollection()
 
+    @get:Optional
+    @get:Input
+    val dontobfuscate: Property<Boolean?> = objects.nullableProperty()
+
     // todo: DSL for excluding default rules
     // also consider pulling coroutines rules from coroutines artifact
     // https://github.com/Kotlin/kotlinx.coroutines/blob/master/kotlinx-coroutines-core/jvm/resources/META-INF/proguard/coroutines.pro
@@ -107,6 +111,10 @@ abstract class AbstractProguardTask : AbstractComposeDesktopTask() {
         }
 
         rootConfigurationFile.ioFile.bufferedWriter().use { writer ->
+            if (dontobfuscate.orNull == true) {
+                writer.writeLn("-dontobfuscate")
+            }
+
             writer.writeLn("""
                 -keep public class ${mainClass.get()} {
                     public static void main(java.lang.String[]);

gradle-plugins/compose/src/test/kotlin/org/jetbrains/compose/test/tests/integration/DesktopApplicationTest.kt

@@ -16,6 +16,7 @@ import java.util.*
 import java.util.jar.JarFile
 import kotlin.collections.HashSet
 import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertFalse
 import org.junit.jupiter.api.Assumptions
 import org.junit.jupiter.api.Test
 
@@ -77,17 +78,43 @@ class DesktopApplicationTest : GradlePluginTestBase() {
 
     @Test
     fun proguard(): Unit = with(testProject(TestProjects.proguard)) {
-        gradle(":runReleaseDistributable").build().checks { check ->
-            check.taskOutcome(":proguardReleaseJars", TaskOutcome.SUCCESS)
+        val enableObfuscation = """
+                compose.desktop {
+                    application {
+                        buildTypes.release.proguard {
+                            obfuscate.set(true)
+                        }
+                    }
+                }
+            """.trimIndent()
 
-            assertEqualTextFiles(file("main-methods.actual.txt"), file("main-methods.expected.txt"))
+        val actualMainImage = file("main-image.actual.png")
+        val expectedMainImage = file("main-image.expected.png")
 
-            val actualMainImage = file("main-image.actual.png")
-            val expectedMainImage = file("main-image.expected.png")
+        fun checkImageBeforeBuild() {
+            assertFalse(actualMainImage.exists(), "'$actualMainImage' exists")
+        }
+        fun checkImageAfterBuild() {
             assert(actualMainImage.readBytes().contentEquals(expectedMainImage.readBytes())) {
                 "The actual image '$actualMainImage' does not match the expected image '$expectedMainImage'"
             }
         }
+
+        checkImageBeforeBuild()
+        gradle(":runReleaseDistributable").build().checks { check ->
+            check.taskOutcome(":proguardReleaseJars", TaskOutcome.SUCCESS)
+            checkImageAfterBuild()
+            assertEqualTextFiles(file("main-methods.actual.txt"), file("main-methods.expected.txt"))
+        }
+
+        file("build.gradle").modify { "$it\n$enableObfuscation" }
+        actualMainImage.delete()
+        checkImageBeforeBuild()
+        gradle(":runReleaseDistributable").build().checks { check ->
+            check.taskOutcome(":proguardReleaseJars", TaskOutcome.SUCCESS)
+            checkImageAfterBuild()
+            assertNotEqualTextFiles(file("main-methods.actual.txt"), file("main-methods.expected.txt"))
+        }
     }
 
     @Test

gradle-plugins/compose/src/test/kotlin/org/jetbrains/compose/test/utils/assertUtils.kt

@@ -51,13 +51,20 @@ internal fun String.checkContains(substring: String) {
 }
 
 internal fun assertEqualTextFiles(actual: File, expected: File) {
-    fun File.normalizedText() = readLines().joinToString("\n") { it.trim() }
-
-    val actualText = actual.normalizedText()
-    val expectedText = expected.normalizedText()
     Assertions.assertEquals(
-        expectedText,
-        actualText,
-        "Expected file '$expected' differs from actual file '$actual'"
+        expected.normalizedText(),
+        actual.normalizedText(),
+        "Content of '$expected' is not equal to content of '$actual'"
+    )
+}
+
+internal fun assertNotEqualTextFiles(actual: File, expected: File) {
+    Assertions.assertNotEquals(
+        expected.normalizedText(),
+        actual.normalizedText(),
+        "Content of '$expected' is equal to content of '$actual'"
     )
-}
+}
+
+private fun File.normalizedText() =
+    readLines().joinToString("\n") { it.trim() }

gradle-plugins/compose/src/test/test-projects/application/proguard/rules.pro

@@ -1,7 +1,3 @@
 -keep public class Main {
     public void keptByKeepRule(...);
-}
-
--keepclassmembernames public class Main {
-    *;
 }