Install jruby-complete.jar, and set "jruby"

When using JRuby, Embulk expects to have an Embulk System Property "jruby"
with a "file:" URI, such as "jruby=file:///path/to/jruby-complete.9.x.y.z.jar"

See EEP-6: JRuby as Optional
https://github.com/embulk/embulk/blob/master/docs/eeps/eep-0006.md

This change is to add a new "jruby" notation in "installEmbulkRunSet"
to download jruby-complete.jar, and set the "jruby" property.

src/main/java/org/embulk/gradle/runset/InstallEmbulkRunSet.java

@@ -31,6 +31,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
+import java.util.Set;
 import org.gradle.api.Action;
 import org.gradle.api.IllegalDependencyNotation;
 import org.gradle.api.InvalidUserDataException;
@@ -64,8 +65,10 @@ public InstallEmbulkRunSet() {
 
         this.project = this.getProject();
         this.logger = this.project.getLogger();
+        this.embulkHome = null;
         this.embulkSystemProperties = new Properties();
         this.embulkSystemPropertiesSource = null;
+        this.jrubyRelative = null;
         this.m2RepoRelative = DEFAULT_M2_REPO_RELATIVE;
 
         final ObjectFactory objectFactory = this.project.getObjects();
@@ -117,6 +120,45 @@ public void artifact(final Object dependencyNotation) {
         }
     }
 
+    /**
+     * Adds a JRuby-complete Maven artifact to be installed.
+     *
+     * <p>It tries to simulate Gradle's dependency notations, but it is yet far from perfect.
+     *
+     * @see <a href="https://github.com/gradle/gradle/blob/v8.7.0/platforms/software/dependency-management/src/main/java/org/gradle/api/internal/notations/DependencyNotationParser.java#L49-L86">org.gradle.api.internal.notations.DependencyNotationParser#create</a>
+     */
+    public InstallEmbulkRunSet jruby(final Object dependencyNotation) {
+        final Dependency dependency;
+        if (dependencyNotation instanceof CharSequence) {
+            dependency = this.dependencyFromCharSequence((CharSequence) dependencyNotation);
+        } else if (dependencyNotation instanceof Map) {
+            dependency = this.dependencyFromMap((Map) dependencyNotation);
+        } else {
+            throw new IllegalDependencyNotation("Supplied jruby module notation is invalid.");
+        }
+
+        // Constructing an independent (detached) Configuration so that its dependencies are not affected by other plugins.
+        final Configuration configuration = this.project.getConfigurations().detachedConfiguration(dependency);
+
+        final ResolvableDependencies resolvableDependencies = configuration.getIncoming();
+        final ArtifactCollection artifactCollection = resolvableDependencies.getArtifacts();
+
+        // Getting the JAR file.
+        final ArrayList<ComponentIdentifier> componentIds = new ArrayList<>();
+        final Set<ResolvedArtifactResult> resolvedArtifactResults = artifactCollection.getArtifacts();
+        if (resolvedArtifactResults.isEmpty()) {
+            throw new IllegalDependencyNotation("Supplied jruby module notation is unavailable.");
+        }
+        if (resolvedArtifactResults.size() > 1) {
+            throw new IllegalDependencyNotation("Supplied jruby module notation has dependencies. Specify jruby-complete instead.");
+        }
+
+        final ResolvedArtifactResult resolvedArtifactResult = resolvedArtifactResults.stream().findFirst().get();
+        this.jrubyRelative = this.fromArtifact(resolvedArtifactResult, "jar");
+
+        return this;
+    }
+
     public InstallEmbulkRunSet embulkHome(final File dir) {
         if (dir == null) {
             throw new InvalidUserDataException("Supplied embulkHome is null.");
@@ -140,6 +182,8 @@ public InstallEmbulkRunSet embulkHome(final File dir) {
             this.logger.lifecycle("Supplied embulkHome \"{}\" does not exist, then will be created.", dir);
         }
 
+        this.embulkHome = dir.toPath();
+
         super.into(dir);
         return this;
     }
@@ -185,18 +229,20 @@ public final Copy into(final Object destPath, final Action<? super CopySpec> cop
         throw new InvalidUserDataException("\"into\" is not permitted in InstallEmbulkRunSet. Use \"embulkHome\" instead.");
     }
 
-    private void fromArtifact(final ResolvedArtifactResult resolvedArtifactResult, final String artifactType) {
+    private Path fromArtifact(final ResolvedArtifactResult resolvedArtifactResult, final String artifactType) {
         final ComponentIdentifier id = resolvedArtifactResult.getId().getComponentIdentifier();
         final File file = resolvedArtifactResult.getFile();
 
         if (id instanceof ModuleComponentIdentifier) {
             final Path modulePath = moduleToPath((ModuleComponentIdentifier) id);
+            final Path modulePathFromHome = this.m2RepoRelative.resolve(modulePath);
             this.logger.lifecycle("Setting to copy {}:{} into {}", id, artifactType, modulePath);
             this.logger.info("Cached file: {}", file);
             this.from(file, copy -> {
-                copy.into(this.m2RepoRelative.resolve(modulePath).toFile());
+                copy.into(modulePathFromHome.toFile());
                 copy.setDuplicatesStrategy(DuplicatesStrategy.EXCLUDE);
             });
+            return modulePathFromHome.resolve(file.getName());
         } else if (id instanceof ProjectComponentIdentifier) {
             throw new IllegalDependencyNotation("Cannot install artifacts for a project component (" + id.getDisplayName() + ")");
         } else {
@@ -273,6 +319,16 @@ private static Map<Object, Object> castMap(final Map map) {
     @Override
     @TaskAction
     protected void copy() {
+        if (this.embulkHome == null) {
+            throw new InvalidUserDataException("embulkHome is not supplied.");
+        }
+
+        if (this.jrubyRelative != null) {
+            this.embulkSystemProperties.setProperty(
+                    "jruby",
+                    this.embulkHome.resolve(this.jrubyRelative).toUri().toString());
+        }
+
         if (this.embulkSystemPropertiesSource != null) {
             try (final OutputStream out = Files.newOutputStream(this.embulkSystemPropertiesSource)) {
                 this.embulkSystemProperties.store(
@@ -314,7 +370,11 @@ private synchronized void createPropertiesSourceAndSetToCopy() {
 
     private final Properties embulkSystemProperties;
 
+    private Path embulkHome;
+
     private Path embulkSystemPropertiesSource;
 
+    private Path jrubyRelative;
+
     private Path m2RepoRelative;
 }

src/test/java/org/embulk/gradle/runset/TestEmbulkRunSetPlugin.java

@@ -19,9 +19,12 @@
 import static org.embulk.gradle.runset.Util.prepareProjectDir;
 import static org.embulk.gradle.runset.Util.runGradle;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URI;
+import java.net.URISyntaxException;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -34,7 +37,7 @@
 
 public class TestEmbulkRunSetPlugin  {
     @Test
-    public void testSimple(@TempDir Path tempDir) throws IOException {
+    public void testSimple(@TempDir Path tempDir) throws IOException, URISyntaxException {
         final Path projectDir = prepareProjectDir(tempDir, "simple");
 
         runGradle(projectDir, "installEmbulkRunSet");
@@ -53,8 +56,22 @@ public FileVisitResult visitFile(final Path file, final BasicFileAttributes attr
         try (final InputStream in = Files.newInputStream(propertiesPath)) {
             properties.load(in);
         }
-        assertEquals(2, properties.size());
+        assertEquals(3, properties.size());
         assertEquals("value", properties.getProperty("key"));
         assertEquals(Paths.get("lib").resolve("m2").resolve("repository").toString(), properties.getProperty("m2_repo"));
+        assertEquals("lib/m2/repository", properties.getProperty("m2_repo"));
+        final URI jrubyUri = new URI(properties.getProperty("jruby"));
+        assertEquals("file", jrubyUri.getScheme());
+        final Path jrubyAbsolutePath = Paths.get(jrubyUri.getPath());
+        assertTrue(jrubyAbsolutePath.isAbsolute());
+        assertTrue(jrubyAbsolutePath.endsWith(
+                       Paths.get("lib")
+                       .resolve("m2")
+                       .resolve("repository")
+                       .resolve("org")
+                       .resolve("jruby")
+                       .resolve("jruby-complete")
+                       .resolve("9.1.15.0")
+                       .resolve("jruby-complete-9.1.15.0.jar")));
     }
 }

src/test/resources/simple/build.gradle

@@ -8,6 +8,7 @@ repositories {
 
 installEmbulkRunSet {
     embulkHome file("${project.buildDir}/simple")
+    jruby "org.jruby:jruby-complete:9.1.15.0"
     m2RepoRelative "lib/m2/repository"
     embulkSystemProperty "key", "value"
     artifact "org.embulk:embulk-input-postgresql:0.13.2"