New feature - the ability to include other YAML files using the "includes" property was added.

gremlin-server/src/test/java/org/apache/tinkerpop/gremlin/driver/remote/AbstractFeatureTest.java

@@ -35,10 +35,10 @@ public abstract class AbstractFeatureTest {
 
     @BeforeClass
     public static void setUp() throws Exception {
-        final InputStream stream = GremlinServer.class.getResourceAsStream("gremlin-server-integration.yaml");
-        final Settings settings = Settings.read(stream);
-        ServerTestHelper.rewritePathsInGremlinServerSettings(settings);
+        var filePath = "classpath:" + GremlinServer.class.getPackageName().replace(".", "/") + "/gremlin-server-integration.yaml";
+        final Settings settings = Settings.read(filePath);
 
+        ServerTestHelper.rewritePathsInGremlinServerSettings(settings);
         server = new GremlinServer(settings);
         server.start().get(100, TimeUnit.SECONDS);
     }

gremlin-server/src/test/java/org/apache/tinkerpop/gremlin/driver/remote/AbstractRemoteGraphProvider.java

@@ -209,8 +209,8 @@ public static Cluster.Builder createClusterBuilder(final Serializers serializer)
     }
 
     public static void startServer() throws Exception {
-        final InputStream stream = GremlinServer.class.getResourceAsStream("gremlin-server-integration.yaml");
-        final Settings settings = Settings.read(stream);
+        var filePath = "classpath:" + GremlinServer.class.getPackageName().replace(".", "/") + "/gremlin-server-integration.yaml";
+        final Settings settings = Settings.read(filePath);
         ServerTestHelper.rewritePathsInGremlinServerSettings(settings);
 
         settings.maxContentLength = 1024000;

gremlin-server/src/test/java/org/apache/tinkerpop/gremlin/server/AbstractGremlinServerIntegrationTest.java

@@ -82,9 +82,6 @@ protected void overrideEvaluationTimeout(final long timeoutInMillis) {
         overriddenSettings.evaluationTimeout = timeoutInMillis;
     }
 
-    public InputStream getSettingsInputStream() {
-        return AbstractGremlinServerIntegrationTest.class.getResourceAsStream("gremlin-server-integration.yaml");
-    }
 
     @Before
     public void setUp() throws Exception {
@@ -123,8 +120,8 @@ public void startServer() throws Exception {
     }
 
     public CompletableFuture<ServerGremlinExecutor> startServerAsync() throws Exception {
-        final InputStream stream = getSettingsInputStream();
-        final Settings settings = Settings.read(stream);
+        var filePath = "classpath:" + GremlinServer.class.getPackageName().replace(".", "/") + "/gremlin-server-integration.yaml";
+        final Settings settings = Settings.read(filePath);
         overriddenSettings = overrideSettings(settings);
         ServerTestHelper.rewritePathsInGremlinServerSettings(overriddenSettings);
         if (GREMLIN_SERVER_EPOLL) {

gremlin-server/src/test/java/org/apache/tinkerpop/gremlin/server/GremlinServerShutdownIntegrationTest.java

@@ -51,8 +51,8 @@ public InputStream getSettingsInputStream() {
     }
 
     public Settings getBaseSettings() {
-        final InputStream stream = getSettingsInputStream();
-        return Settings.read(stream);
+        var filePath = "classpath:" + GremlinServer.class.getPackageName().replace(".", "/") + "/gremlin-server-integration.yaml";
+        return Settings.read(filePath);
     }
 
     public CompletableFuture<ServerGremlinExecutor> startServer(final Settings settings) throws Exception {

gremlin-server/src/test/java/org/apache/tinkerpop/gremlin/server/SettingsTest.java

@@ -18,15 +18,33 @@
  */
 package org.apache.tinkerpop.gremlin.server;
 
-import org.junit.Test;
+import org.apache.commons.io.FileUtils;
+import org.junit.*;
 import org.yaml.snakeyaml.Yaml;
 import org.yaml.snakeyaml.constructor.Constructor;
 
+import java.io.IOException;
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Map;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.*;
 
 public class SettingsTest {
+    private Path tempDir;
+
+    @Before
+    public void before() throws Exception {
+        tempDir = Files.createTempDirectory(SettingsTest.class.getSimpleName());
+    }
+
+    @After
+    public void afterClass() throws Exception {
+        FileUtils.deleteDirectory(tempDir.toFile());
+    }
 
     private static class CustomSettings extends Settings {
         public String customValue = "localhost";
@@ -39,7 +57,7 @@ public static CustomSettings read(final InputStream stream) {
     }
 
     @Test
-    public void constructorCanBeExtendToParseCustomYamlAndSettingsValues() throws Exception {
+    public void constructorCanBeExtendToParseCustomYamlAndSettingsValues() {
         final InputStream stream = SettingsTest.class.getResourceAsStream("custom-gremlin-server.yaml");
 
         final CustomSettings settings = CustomSettings.read(stream);
@@ -49,11 +67,228 @@ public void constructorCanBeExtendToParseCustomYamlAndSettingsValues() throws Ex
     }
 
     @Test
-    public void defaultCustomValuesAreHandledCorrectly() throws Exception {
+    public void defaultCustomValuesAreHandledCorrectly() {
         final InputStream stream = SettingsTest.class.getResourceAsStream("gremlin-server-integration.yaml");
 
         final CustomSettings settings = CustomSettings.read(stream);
 
         assertEquals("localhost", settings.customValue);
     }
+
+    @Test
+    public void testSimpleIncludeAndMerge() throws IOException {
+        createFile("base.yaml", "graphs: { graph1: 'base1', graph2: 'base2' }");
+        createFile("root.yaml",
+                "includes: ['base.yaml']\n" +
+                        "graphs:\n" +
+                        "  graph1: 'root'"
+
+        );
+
+        Settings result = Settings.read(tempDir.resolve("root.yaml").toString());
+
+        assertEquals("root", result.graphs.get("graph1"));
+        assertEquals("base2", result.graphs.get("graph2"));
+    }
+
+    @Test
+    public void testDeepMerge() throws IOException {
+        createFile("base.yaml",
+                "scriptEngines:\n" +
+                        "  engine1:\n" +
+                        "    config: \n" +
+                        "      connector: { port: 8080, protocol: 'http' }\n" +
+                        "      logging: { level: 'INFO' }"
+        );
+        createFile("root.yaml",
+                "includes: ['base.yaml']\n" +
+                        "scriptEngines:\n" +
+                        "  engine1:\n" +
+                        "    config: \n" +
+                        "      connector: { port: 9090 }\n" +
+                        "      logging: { file: '/var/log/app.log' }"
+        );
+
+
+        Settings result = Settings.read(tempDir.resolve("root.yaml").toString());
+        @SuppressWarnings("unchecked")
+        Map<String, Object> connector = (Map<String, Object>) result.scriptEngines.get("engine1").config.get("connector");
+        @SuppressWarnings("unchecked")
+        Map<String, Object> logging = (Map<String, Object>) result.scriptEngines.get("engine1").config.get("logging");
+
+        assertEquals(9090, connector.get("port"));
+        assertEquals("http", connector.get("protocol"));
+        assertEquals("INFO", logging.get("level"));
+        assertEquals("/var/log/app.log", logging.get("file"));
+    }
+
+    @Test
+    public void testMultipleIncludesOrder() throws IOException {
+        // Arrange
+        createFile("one.yaml", "host: localhost1");
+        createFile("two.yaml", "host: localhost2");
+        createFile("root.yaml",
+                "includes: ['one.yaml', 'two.yaml']\n" // two should overwrite one
+        );
+
+        Settings result = Settings.read(tempDir.resolve("root.yaml").toString());
+
+        assertEquals("localhost2", result.host);
+    }
+
+    @Test
+    public void testListReplacement() throws IOException {
+        createFile("base.yaml", "serializers: \n" +
+                "  [ {className: 'a'} , {className: 'b' }]");
+        createFile("root.yaml",
+                "includes: ['base.yaml']\n" +
+                        "serializers: \n" +
+                        "  [ {className: 'c'}]");
+        Settings result = Settings.read(tempDir.resolve("root.yaml").toString());
+
+        List<Settings.SerializerSettings> serializers = result.serializers;
+        assertEquals(1, serializers.size());
+        assertEquals("c", serializers.get(0).className);
+    }
+
+    @Test
+    public void testRelativePathResolution() throws IOException {
+        // Structure:
+        // root.yaml
+        // subdir/
+        //   child.yaml
+        //   nested/
+        //     grandchild.yaml
+
+        createFile("subdir/nested/grandchild.yaml", "host: 0.0.0.0");
+        createFile("subdir/child.yaml",
+                "includes: ['nested/grandchild.yaml']\n" +
+                        "port: 9090"
+        );
+        createFile("root.yaml",
+                "includes: ['subdir/child.yaml']\n" +
+                        "threadPoolWorker: 1000"
+        );
+
+        Settings result = Settings.read(tempDir.resolve("root.yaml").toString());
+        assertEquals(9090, result.port);
+        assertEquals(1000, result.threadPoolWorker);
+        assertEquals("0.0.0.0", result.host);
+    }
+
+    @Test
+    public void testParentPathResolution() throws IOException {
+        // root.yaml -> includes 'config/sub.yaml'
+        // config/sub.yaml -> includes '../shared.yaml'
+
+        createFile("shared.yaml", "host: 0.0.0.0");
+        createFile("config/sub.yaml", "includes: ['../shared.yaml']");
+        createFile("root.yaml", "includes: ['config/sub.yaml']");
+
+        Settings result = Settings.read(tempDir.resolve("root.yaml").toString());
+
+        assertEquals("0.0.0.0", result.host);
+    }
+
+    @Test
+    public void testCircularDependency() throws IOException {
+        createFile("a.yaml", "includes: ['b.yaml']");
+        createFile("b.yaml", "includes: ['a.yaml']");
+
+        try {
+            Settings.read(tempDir.resolve("a.yaml").toString());
+            Assert.fail("Expected exception");
+        } catch (Exception e) {
+            assertTrue(e.getMessage().contains("Circular dependency detected"));
+        }
+    }
+
+    @Test
+    public void testDiamondDependency() throws IOException {
+        // A -> B, A -> C
+        // B -> D
+        // C -> D
+        // This is valid. D should be loaded twice (or handled gracefully) but not cause a cycle error.
+
+        createFile("d.yaml", "host: '0.0.0.0'");
+        createFile("b.yaml", "includes: ['d.yaml']\nport: 9090");
+        createFile("c.yaml", "includes: ['d.yaml']\nthreadPoolWorker: 1000");
+        createFile("a.yaml", "includes: ['b.yaml', 'c.yaml']");
+
+        Settings result = Settings.read(tempDir.resolve("a.yaml").toString());
+        assertEquals(9090, result.port);
+        assertEquals(1000, result.threadPoolWorker);
+        assertEquals("0.0.0.0", result.host);
+    }
+
+    @Test
+    public void testClasspathResolution() {
+        Settings result = Settings.read("classpath:org/apache/tinkerpop/gremlin/server/settings/config/root.yaml");
+
+        assertEquals(9090, result.port);
+        assertEquals(1000, result.threadPoolWorker);
+        assertEquals("localhost1", result.host);
+    }
+
+    @Test
+    public void testFileSystemIncludingClasspath() throws IOException {
+        createFile("disk.yaml", "includes: ['classpath:org/apache/tinkerpop/gremlin/server/settings/config/root.yaml']\ngremlinPool: 2000");
+        Settings result = Settings.read(tempDir.resolve("disk.yaml").toString());
+
+        assertEquals(9090, result.port);
+        assertEquals(1000, result.threadPoolWorker);
+        assertEquals("localhost1", result.host);
+        assertEquals(2000, result.gremlinPool);
+    }
+
+    @Test
+    public void testMissingFile() {
+        try {
+            Settings.read(tempDir.resolve("root.yaml").toString());
+            Assert.fail("Expected exception");
+        } catch (Exception e) {
+            String msg = e.getMessage();
+            assertTrue(msg.contains("root.yaml"));
+            assertTrue(msg.contains("Error loading YAML from"));
+        }
+    }
+
+    @Test
+    public void testMissingIncludedFile() throws IOException {
+        createFile("root.yaml", "includes: ['non_existent.yaml']");
+        try {
+            Settings.read(tempDir.resolve("root.yaml").toString());
+            Assert.fail("Expected exception");
+        } catch (Exception e) {
+            String msg = e.getMessage();
+            assertTrue(msg.contains("non_existent.yaml"));
+            assertTrue(msg.contains("Error loading YAML from"));
+        }
+    }
+
+    @Test
+    public void testMalformedIncludes() throws IOException {
+        createFile("root.yaml", "includes: 'just_a_string.yaml'");
+
+        try {
+            Settings.read(tempDir.resolve("root.yaml").toString());
+            Assert.fail("Expected exception");
+        } catch (Exception e) {
+            String msg = e.getMessage();
+            assertTrue(msg.contains("'includes' must be a list of strings"));
+        }
+    }
+
+    @Test
+    public void testEmptyFile() throws IOException {
+        createFile("empty.yaml", "");
+        Settings settings = Settings.read(tempDir.resolve("empty.yaml").toString());
+        assertNotNull(settings);
+    }
+
+    private void createFile(String fileName, String content) throws IOException {
+        Path file = tempDir.resolve(fileName);
+        Files.createDirectories(file.getParent());
+        Files.write(file, content.getBytes(StandardCharsets.UTF_8));
+    }
 }

gremlin-server/src/test/java/org/apache/tinkerpop/gremlin/server/util/CheckedGraphManagerTest.java

@@ -25,6 +25,7 @@
 import java.util.function.Function;
 
 import org.apache.tinkerpop.gremlin.server.GraphManager;
+import org.apache.tinkerpop.gremlin.server.GremlinServer;
 import org.apache.tinkerpop.gremlin.server.Settings;
 
 import org.junit.Before;
@@ -36,8 +37,8 @@ public class CheckedGraphManagerTest {
 
     @Before
     public void before() throws Exception {
-        settings = Settings
-                .read(CheckedGraphManagerTest.class.getResourceAsStream("../gremlin-server-integration.yaml"));
+        var filePath = "classpath:" + GremlinServer.class.getPackageName().replace(".", "/") + "/gremlin-server-integration.yaml";
+        settings = Settings.read(filePath);
     }
 
     /**