Adding option allowModuleInfos() to make it optional to include modul…

…e-info.class files easily

src/main/groovy/com/github/jengelman/gradle/plugins/shadow/ShadowJavaPlugin.groovy

@@ -24,6 +24,9 @@ class ShadowJavaPlugin implements Plugin<Project> {
     public static final String SHADOW_GROUP = 'Shadow'
     public static final String SHADOW_RUNTIME_ELEMENTS_CONFIGURATION_NAME = 'shadowRuntimeElements'
 
+    public static final String MODULE_INFO_CLASS = 'module-info.class'
+
+    private final ProjectConfigurationActionContainer configurationActionContainer
     private final SoftwareComponentFactory softwareComponentFactory
 
     @Inject
@@ -101,6 +104,20 @@ class ShadowJavaPlugin implements Plugin<Project> {
                             project.configurations.runtime,
             ]
             shadow.exclude('META-INF/INDEX.LIST', 'META-INF/*.SF', 'META-INF/*.DSA', 'META-INF/*.RSA', 'module-info.class')
+            shadow.configurations = [project.configurations.findByName('runtimeClasspath') ?
+                                             project.configurations.runtimeClasspath : project.configurations.runtime]
+            /*
+             Remove excludes like this:
+             shadowJar {
+               ...
+               allowModuleInfos()
+             }
+             */
+            def excludes = ['META-INF/INDEX.LIST', 'META-INF/*.SF', 'META-INF/*.DSA', 'META-INF/*.RSA']
+            if (!shadow.isAllowModuleInfos()) {
+                excludes.add(MODULE_INFO_CLASS)
+            }
+            shadow.exclude(excludes)
         }
         project.artifacts.add(shadowConfiguration.name, taskProvider)
         return taskProvider

src/main/groovy/com/github/jengelman/gradle/plugins/shadow/internal/RelocationUtil.groovy

@@ -1,5 +1,6 @@
 package com.github.jengelman.gradle.plugins.shadow.internal
 
+import com.github.jengelman.gradle.plugins.shadow.ShadowJavaPlugin
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 import java.util.jar.JarFile
 
@@ -11,7 +12,7 @@ class RelocationUtil {
             configuration.files.each { jar ->
                 JarFile jf = new JarFile(jar)
                 jf.entries().each { entry ->
-                    if (entry.name.endsWith(".class") && entry.name != "module-info.class") {
+                    if (entry.name.endsWith(".class") && entry.name != ShadowJavaPlugin.MODULE_INFO_CLASS) {
                         packages << entry.name[0..entry.name.lastIndexOf('/') - 1].replaceAll('/', '.')
                     }
                 }

src/main/groovy/com/github/jengelman/gradle/plugins/shadow/tasks/ShadowCopyAction.groovy

@@ -1,5 +1,6 @@
 package com.github.jengelman.gradle.plugins.shadow.tasks
 
+import com.github.jengelman.gradle.plugins.shadow.ShadowJavaPlugin
 import com.github.jengelman.gradle.plugins.shadow.ShadowStats
 import com.github.jengelman.gradle.plugins.shadow.impl.RelocatorRemapper
 import com.github.jengelman.gradle.plugins.shadow.internal.UnusedTracker
@@ -41,6 +42,7 @@ import org.objectweb.asm.ClassVisitor
 import org.objectweb.asm.ClassWriter
 import org.objectweb.asm.commons.ClassRemapper
 
+import javax.annotation.Nonnull
 import javax.annotation.Nullable
 import java.util.zip.ZipException
 
@@ -59,11 +61,13 @@ class ShadowCopyAction implements CopyAction {
     private final boolean preserveFileTimestamps
     private final boolean minimizeJar
     private final UnusedTracker unusedTracker
+    private final boolean allowModuleInfos
 
     ShadowCopyAction(File zipFile, ZipCompressor compressor, DocumentationRegistry documentationRegistry,
                      String encoding, List<Transformer> transformers, List<Relocator> relocators,
                      PatternSet patternSet, ShadowStats stats,
-                     boolean preserveFileTimestamps, boolean minimizeJar, UnusedTracker unusedTracker) {
+                     boolean preserveFileTimestamps, boolean minimizeJar, UnusedTracker unusedTracker,
+                     boolean allowModuleInfos) {
 
         this.zipFile = zipFile
         this.compressor = compressor
@@ -76,6 +80,7 @@ class ShadowCopyAction implements CopyAction {
         this.preserveFileTimestamps = preserveFileTimestamps
         this.minimizeJar = minimizeJar
         this.unusedTracker = unusedTracker
+        this.allowModuleInfos = allowModuleInfos
     }
 
     @Override
@@ -201,7 +206,17 @@ class ShadowCopyAction implements CopyAction {
         private final Set<String> unused
         private final ShadowStats stats
 
-        private Map<String, Map> visitedFiles = new HashMap<>()
+        private class VisitedFileInfo {
+            long size
+            RelativePath originJar
+
+            VisitedFileInfo(long size, @Nonnull RelativePath originJar) {
+                this.size = size
+                this.originJar = originJar
+            }
+        }
+
+        private Map<String, VisitedFileInfo> visitedFiles = new HashMap<>()
 
         StreamAction(ZipOutputStream zipOutStr, String encoding, List<Transformer> transformers,
                      List<Relocator> relocators, PatternSet patternSet, Set<String> unused,
@@ -235,7 +250,7 @@ class ShadowCopyAction implements CopyAction {
                 originJar = new RelativePath(false)
             }
 
-            visitedFiles.put(path.toString(), [size: size, originJar: originJar])
+            visitedFiles.put(path.toString(), new VisitedFileInfo(size, originJar))
             return true
         }
 
@@ -312,37 +327,7 @@ class ShadowCopyAction implements CopyAction {
             if (archiveFile.classFile || !isTransformable(archiveFile)) {
                 String path = archiveFilePath.toString()
 
-                if (path.endsWith("module-info.class")) {
-                    log.warn("module-info collision")
-
-                    def moduleFileName = "module-info"
-                    def moduleFileSuffix = ".class"
-                    File disassembleModFile = File.createTempFile(moduleFileName, moduleFileSuffix)
-
-                    try (InputStream is = archive.getInputStream(archiveFilePath.entry)) {
-                        try (OutputStream os = new FileOutputStream(disassembleModFile)) {
-                            IOUtils.copyLarge(is, os)
-                        }
-                    }
-
-                    ProcessBuilder processBuilder = new ProcessBuilder("javap", disassembleModFile.absolutePath)
-                    processBuilder.redirectErrorStream(true)
-                    Process process = processBuilder.start()
-                    InputStream inputStream = process.getInputStream()
-                    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))
-                    String line
-
-                    while ((line = reader.readLine()) != null) {
-                        log.warn(line)
-                    }
-
-                    int exitCode = process.waitFor()
-                    if (exitCode != 0) {
-                        log.warn("Process exited with code " + exitCode)
-                    }
-
-                    log.warn("module-info collision end")
-                }
+                listModuleInfoOnDemand(path, archive, archiveFilePath)
 
                 if (recordVisit(path, archiveFileSize, archiveFilePath) && !isUnused(archiveFilePath.entry.name)) {
                     if (!remapper.hasRelocators() || !archiveFile.classFile) {
@@ -382,6 +367,52 @@ class ShadowCopyAction implements CopyAction {
             }
         }
 
+        /**
+         Information about the 'module-info.class' if it isn't excluded. Including can be done with
+         <code>allowModuleInfos()</code>, like this:
+         <pre><code>
+         shadowJar {
+            ...
+            allowModuleInfos()
+         }
+         </code></pre>
+         Based on the discussion in issue 710: <a href="https://github.com/GradleUp/shadow/issues/710">GitHub Issue #710</a>.
+         */
+        private void listModuleInfoOnDemand(String path, ZipFile archive, RelativeArchivePath archiveFilePath) {
+            if (path.endsWith(ShadowJavaPlugin.MODULE_INFO_CLASS) && allowModuleInfos) {
+                log.warn("======== Warning: {}/{} contains module-info - Listing content ========",
+                        RelativePath.parse(true, archive.name).lastName, path)
+
+                def moduleFileName = "module-info"
+                def moduleFileSuffix = ".class"
+                File disassembleModFile = File.createTempFile(moduleFileName, moduleFileSuffix)
+
+                try (InputStream is = archive.getInputStream(archiveFilePath.entry)) {
+                    try (OutputStream os = new FileOutputStream(disassembleModFile)) {
+                        IOUtils.copyLarge(is, os)
+                    }
+                }
+
+                ProcessBuilder processBuilder = new ProcessBuilder("javap", disassembleModFile.absolutePath)
+                processBuilder.redirectErrorStream(true)
+                Process process = processBuilder.start()
+                InputStream inputStream = process.getInputStream()
+                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))
+
+                String line
+                while ((line = reader.readLine()) != null) {
+                    log.warn(line)
+                }
+
+                int exitCode = process.waitFor()
+                if (exitCode != 0) {
+                    log.warn("Process exited with code " + exitCode)
+                }
+
+                log.warn("======== module-info content listing end ========")
+            }
+        }
+
         private void addParentDirectories(RelativeArchivePath file) {
             if (file) {
                 addParentDirectories(file.parent)

src/main/groovy/com/github/jengelman/gradle/plugins/shadow/tasks/ShadowJar.java

@@ -1,5 +1,6 @@
 package com.github.jengelman.gradle.plugins.shadow.tasks;
 
+import com.github.jengelman.gradle.plugins.shadow.ShadowJavaPlugin;
 import com.github.jengelman.gradle.plugins.shadow.ShadowStats;
 import com.github.jengelman.gradle.plugins.shadow.internal.DefaultDependencyFilter;
 import com.github.jengelman.gradle.plugins.shadow.internal.DependencyFilter;
@@ -72,6 +73,8 @@ public FileCollection call() {
         }
     });
 
+    private boolean isAllowModuleInfos;
+
     public ShadowJar() {
         super();
         setDuplicatesStrategy(
@@ -142,7 +145,7 @@ protected CopyAction createCopyAction() {
                 getSourceSetsClassesDirs().getFiles(), getToMinimize()) : null;
         return new ShadowCopyAction(getArchiveFile().get().getAsFile(), getInternalCompressor(), documentationRegistry,
                 this.getMetadataCharset(), transformers, relocators, getRootPatternSet(), shadowStats,
-                isPreserveFileTimestamps(), minimizeJar, unusedTracker);
+                isPreserveFileTimestamps(), minimizeJar, unusedTracker, isAllowModuleInfos);
     }
 
     @Classpath
@@ -263,6 +266,23 @@ public ShadowJar removeDefaultTransformers() {
         return this;
     }
 
+    /**
+     * Allows module-info.class's to be included in the final jar, and informs about the contents
+     * of the module-info.class files it finds.
+     *
+     * @return this
+     */
+    public ShadowJar allowModuleInfos() {
+        this.isAllowModuleInfos = true;
+        getExcludes().remove(ShadowJavaPlugin.MODULE_INFO_CLASS);
+        return this;
+    }
+
+    @Internal
+    public boolean isAllowModuleInfos() {
+        return isAllowModuleInfos;
+    }
+
     private boolean isCacheableTransform(Class<? extends Transformer> clazz) {
         return clazz.isAnnotationPresent(CacheableTransformer.class);
     }

src/test/groovy/com/github/jengelman/gradle/plugins/shadow/ShadowPluginSpec.groovy

@@ -156,6 +156,8 @@ class ShadowPluginSpec extends PluginSpecification {
         /* Shouldn't appear, because the default StandardFileTransformer should've merged it,
            instead of just dropping all following licenses. */
         assert !result.output.contains('license.txt')
+        // No module listing should appear. module-info.class is excluded by default.
+        assert !result.output.contains('open module org.example')
     }
 
     def 'Tests the removal of the default transformer'() {
@@ -167,7 +169,7 @@ class ShadowPluginSpec extends PluginSpecification {
             |task shadow(type: ${ShadowJar.name}) {
             |    destinationDirectory = buildDir
             |    archiveBaseName = 'shadow'
-            |    removeDefaultTransformers()            
+            |    removeDefaultTransformers()
             |    from('${artifact.path}')
             |    from('${project.path}')
             |}
@@ -182,6 +184,32 @@ class ShadowPluginSpec extends PluginSpecification {
                                 /\s+IGNORING test\.json from test-project-1\.0-SNAPSHOT.jar, size is different/
         // Without the StandardFileTransformer there should be a warning about multiple license files with the same name.
         assert result.output.contains('license.txt')
+        // No module listing should appear. module-info.class is excluded by default.
+        assert !result.output.contains('open module org.example')
+    }
+
+    def 'Tests the info about the module-info.class, if removed from standard excludes'() {
+        given:
+        URL artifact = this.class.classLoader.getResource('test-artifact-1.0-SNAPSHOT.jar')
+        URL project = this.class.classLoader.getResource('test-project-1.0-SNAPSHOT.jar')
+
+        buildFile << """
+            |task shadow(type: ${ShadowJar.name}) {
+            |    destinationDirectory = buildDir
+            |    archiveBaseName = 'shadow'
+            |    allowModuleInfos()
+            |    from('${artifact.path}')
+            |    from('${project.path}')
+            |}
+        """.stripMargin()
+
+        when:
+        BuildResult result = run('shadow')
+
+        then:
+        assert result.output.contains('module-info.class')
+        // Because allowModuleInfos() is used, the module listing should appear.
+        assert result.output.contains('open module org.example')
     }
 
     def 'include project sources'() {