Support Isolated Projects

docs/changes/README.md

@@ -3,6 +3,10 @@
 
 ## [Unreleased](https://github.com/GradleUp/shadow/compare/9.3.2...HEAD) - 2026-xx-xx
 
+### Added
+
+- Support Isolated Projects. ([#1139](https://github.com/GradleUp/shadow/pull/1139))
+
 ### Changed
 
 - Allow opting out of adding `shadowJar` into `assemble` lifecycle. ([#1939](https://github.com/GradleUp/shadow/pull/1939))

src/functionalTest/kotlin/com/github/jengelman/gradle/plugins/shadow/BasePluginTest.kt

@@ -415,9 +415,6 @@ abstract class BasePluginTest {
     const val runShadowTask = "tasks.named('$SHADOW_RUN_TASK_NAME', JavaExec)"
     const val jarTask = "tasks.named('jar', Jar)"
 
-    // TODO: enable this flag for all tests once we have fixed all issues with isolated projects.
-    //  See https://github.com/GradleUp/shadow/pull/1139.
-    const val ipArgument = "-Dorg.gradle.unsafe.isolated-projects=true"
     const val infoArgument = "--info"
 
     fun String.toProperties(): Properties = Properties().apply { load(byteInputStream()) }

src/functionalTest/kotlin/com/github/jengelman/gradle/plugins/shadow/JavaPluginsTest.kt

@@ -200,7 +200,7 @@ class JavaPluginsTest : BasePluginTest() {
       .appendText(
         """
         sourceSets {
-          custom
+          create('custom')
         }
         dependencies {
           implementation sourceSets.custom.output
@@ -871,7 +871,6 @@ class JavaPluginsTest : BasePluginTest() {
     val result =
       runWithSuccess(
         serverShadowJarPath,
-        ipArgument,
         infoArgument,
         "-P${ENABLE_DEVELOCITY_INTEGRATION_PROPERTY}=true",
         "-Dscan.dump", // Using scan.dump avoids actually publishing a Build Scan, writing it to a

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/internal/UnusedTracker.kt

@@ -2,16 +2,51 @@ package com.github.jengelman.gradle.plugins.shadow.internal
 
 import java.io.File
 import org.gradle.api.Project
-import org.gradle.api.artifacts.Configuration
-import org.gradle.api.artifacts.Dependency
-import org.gradle.api.artifacts.ExternalModuleDependency
-import org.gradle.api.artifacts.FileCollectionDependency
-import org.gradle.api.artifacts.ProjectDependency
+import org.gradle.api.artifacts.component.ModuleComponentIdentifier
+import org.gradle.api.attributes.Category
+import org.gradle.api.attributes.LibraryElements
+import org.gradle.api.attributes.Usage
 import org.gradle.api.file.FileCollection
+import org.gradle.api.plugins.JavaPlugin.API_CONFIGURATION_NAME
+import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.InputFiles
 import org.vafer.jdependency.Clazzpath
 import org.vafer.jdependency.ClazzpathUnit
 
+internal fun Project.getApiJars(): Provider<List<File>> {
+  val apiConfiguration =
+    configurations.findByName(API_CONFIGURATION_NAME) ?: return provider { emptyList() }
+
+  val configName = "shadowMinimizeApi"
+  val shadowApiConfig =
+    if (configurations.names.contains(configName)) {
+      configurations.named(configName)
+    } else {
+      configurations.register(configName) {
+        it.isCanBeResolved = true
+        it.isCanBeConsumed = false
+        it.attributes { attrs ->
+          attrs.attribute(Usage.USAGE_ATTRIBUTE, objects.named(Usage::class.java, Usage.JAVA_API))
+          attrs.attribute(
+            Category.CATEGORY_ATTRIBUTE,
+            objects.named(Category::class.java, Category.LIBRARY),
+          )
+          attrs.attribute(
+            LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE,
+            objects.named(LibraryElements::class.java, LibraryElements.JAR),
+          )
+        }
+        it.extendsFrom(apiConfiguration)
+      }
+    }
+
+  return shadowApiConfig.flatMap { shadowApi ->
+    shadowApi.incoming.artifacts.resolvedArtifacts.map { artifacts ->
+      artifacts.filter { it.id.componentIdentifier !is ModuleComponentIdentifier }.map { it.file }
+    }
+  }
+}
+
 /** Tracks unused classes in the project classpath. */
 internal class UnusedTracker(
   sourceSetsClassesDirs: Iterable<File>,
@@ -41,44 +76,4 @@ internal class UnusedTracker(
       cp.addClazzpathUnit(jarOrDir)
     }
   }
-
-  companion object {
-    fun getApiJarsFromProject(project: Project): FileCollection {
-      val apiDependencies =
-        project.configurations.findByName("api")?.dependencies ?: return project.files()
-      val runtimeConfiguration = project.runtimeConfiguration
-      val apiJars = mutableListOf<File>()
-      apiDependencies.forEach { dep ->
-        when (dep) {
-          is ProjectDependency -> {
-            apiJars.addAll(getApiJarsFromProject(project.project(dep.path)))
-            addJar(runtimeConfiguration, dep, apiJars)
-          }
-          is FileCollectionDependency -> {
-            apiJars.addAll(dep.files)
-          }
-          // Skip BOM dependencies and other non-JAR dependencies.
-          is ExternalModuleDependency -> Unit
-          else -> {
-            addJar(runtimeConfiguration, dep, apiJars)
-            val jarFile =
-              runtimeConfiguration.find { it.name.startsWith("${dep.name}-") } ?: return@forEach
-            apiJars.add(jarFile)
-          }
-        }
-      }
-      return project.files(apiJars)
-    }
-
-    private fun addJar(config: Configuration, dep: Dependency, result: MutableList<File>) {
-      config.find { isProjectDependencyFile(it, dep) }?.let { result.add(it) }
-    }
-
-    private fun isProjectDependencyFile(file: File, dep: Dependency): Boolean {
-      val fileName = file.name
-      val dependencyName = dep.name
-      return fileName == "$dependencyName.jar" ||
-        (fileName.startsWith("$dependencyName-") && fileName.endsWith(".jar"))
-    }
-  }
 }

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/tasks/ShadowJar.kt

@@ -8,6 +8,7 @@ import com.github.jengelman.gradle.plugins.shadow.internal.MinimizeDependencyFil
 import com.github.jengelman.gradle.plugins.shadow.internal.UnusedTracker
 import com.github.jengelman.gradle.plugins.shadow.internal.classPathAttributeKey
 import com.github.jengelman.gradle.plugins.shadow.internal.fileCollection
+import com.github.jengelman.gradle.plugins.shadow.internal.getApiJars
 import com.github.jengelman.gradle.plugins.shadow.internal.mainClassAttributeKey
 import com.github.jengelman.gradle.plugins.shadow.internal.multiReleaseAttributeKey
 import com.github.jengelman.gradle.plugins.shadow.internal.property
@@ -108,7 +109,7 @@ public abstract class ShadowJar : Jar() {
   @get:Classpath
   public open val apiJars: ConfigurableFileCollection =
     objectFactory.fileCollection {
-      minimizeJar.map { if (it) UnusedTracker.getApiJarsFromProject(project) else emptySet() }
+      minimizeJar.map { if (it) project.getApiJars() else emptySet<File>() }
     }
 
   @get:InputFiles

src/testKit/kotlin/com/github/jengelman/gradle/plugins/shadow/testkit/GradleRunner.kt

@@ -28,6 +28,8 @@ val commonGradleArgs =
     "--stacktrace",
     // https://docs.gradle.org/current/userguide/configuration_cache.html#config_cache:usage:parallel
     "-Dorg.gradle.configuration-cache.parallel=true",
+    // https://docs.gradle.org/current/userguide/isolated_projects.html#how_do_i_use_it
+    "-Dorg.gradle.unsafe.isolated-projects=true",
   )
 
 fun gradleRunner(