[Backport 2.x] Change WorkflowData from interface to class

src/main/java/demo/CreateIndexWorkflowStep.java

@@ -65,12 +65,7 @@ public CompletableFuture<WorkflowData> execute(List<WorkflowData> data) {
             } catch (InterruptedException e) {}
             // Simulate response of created index
             CreateIndexResponse response = new CreateIndexResponse(true, true, inputIndex);
-            future.complete(new WorkflowData() {
-                @Override
-                public Map<String, Object> getContent() {
-                    return Map.of("index", response.index());
-                }
-            });
+            future.complete(new WorkflowData(Map.of("index", response.index())));
         });
 
         return future;

src/main/java/org/opensearch/flowframework/template/TemplateParser.java

@@ -76,21 +76,10 @@
             WorkflowData inputData = WorkflowData.EMPTY;
             if (List.of("create_index", "create_another_index").contains(nodeId)) {
                 CreateIndexRequest request = new CreateIndexRequest(nodeObject.get("index_name").getAsString());
-                inputData = new WorkflowData() {
-
-                    @Override
-                    public Map<String, Object> getContent() {
-                        // See CreateIndexRequest ParseFields for source of content keys needed
-                        return Map.of("mappings", request.mappings(), "settings", request.settings(), "aliases", request.aliases());
-                    }
-
-                    @Override
-                    public Map<String, String> getParams() {
-                        // See RestCreateIndexAction for source of param keys needed
-                        return Map.of("index", request.index());
-                    }
-
-                };
+                inputData = new WorkflowData(
+                    Map.of("mappings", request.mappings(), "settings", request.settings(), "aliases", request.aliases()),
+                    Map.of("index", request.index())
+                );
             }
             nodes.add(new ProcessNode(nodeId, workflowStep, inputData));
         }

src/main/java/org/opensearch/flowframework/workflow/CreateIndex/CreateIndexStep.java

@@ -52,12 +52,7 @@ public CompletableFuture<WorkflowData> execute(List<WorkflowData> data) {
             @Override
             public void onResponse(CreateIndexResponse createIndexResponse) {
                 logger.info("created index: {}", createIndexResponse.index());
-                future.complete(new WorkflowData() {
-                    @Override
-                    public Map<String, Object> getContent() {
-                        return Map.of("index-name", createIndexResponse.index());
-                    }
-                });
+                future.complete(new WorkflowData(Map.of("index-name", createIndexResponse.index())));
             }
 
             @Override

src/main/java/org/opensearch/flowframework/workflow/WorkflowData.java

@@ -12,29 +12,53 @@
 import java.util.Map;
 
 /**
- * Interface representing data provided as input to, and produced as output from, {@link WorkflowStep}s.
+ * Class encapsulating data provided as input to, and produced as output from, {@link WorkflowStep}s.
  */
-public interface WorkflowData {
+public class WorkflowData {
 
     /**
      * An object representing no data, useful when a workflow step has no required input or output.
      */
-    WorkflowData EMPTY = new WorkflowData() {
-    };
+    public static WorkflowData EMPTY = new WorkflowData();
+
+    private final Map<String, Object> content;
+    private final Map<String, String> params;
+
+    private WorkflowData() {
+        this(Collections.emptyMap(), Collections.emptyMap());
+    }
+
+    /**
+     * Instantiate this object with content and empty params.
+     * @param content The content map
+     */
+    public WorkflowData(Map<String, Object> content) {
+        this(content, Collections.emptyMap());
+    }
+
+    /**
+     * Instantiate this object with content and params.
+     * @param content The content map
+     * @param params The params map
+     */
+    public WorkflowData(Map<String, Object> content, Map<String, String> params) {
+        this.content = Map.copyOf(content);
+        this.params = Map.copyOf(params);
+    }
 
     /**
-     * Accesses a map containing the content of the workflow step. This represents the data associated with a Rest API request.
-     * @return the content of this step.
+     * Returns a map which represents the content associated with a Rest API request or response.
+     * @return the content of this data.
      */
-    default Map<String, Object> getContent() {
-        return Collections.emptyMap();
+    public Map<String, Object> getContent() {
+        return this.content;
     };
 
     /**
-     * Accesses a map containing the params of this workflow step. This represents the params associated with a Rest API request, parsed from the URI.
-     * @return the params of this step.
+     * Returns a map represents the params associated with a Rest API request, parsed from the URI.
+     * @return the params of this data.
      */
-    default Map<String, String> getParams() {
-        return Collections.emptyMap();
+    public Map<String, String> getParams() {
+        return this.params;
     };
 }

src/test/java/org/opensearch/flowframework/template/ProcessNodeTests.java

@@ -19,7 +19,6 @@
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
-import java.util.concurrent.TimeUnit;
 
 @ThreadLeakScope(Scope.NONE)
 public class ProcessNodeTests extends OpenSearchTestCase {
@@ -49,12 +48,13 @@ public String getName() {
         assertEquals(Collections.emptySet(), nodeA.getPredecessors());
         assertEquals("A", nodeA.toString());
 
-        // TODO: Once we can get OpenSearch Thread Pool for this execute method, create an IT and don't test execute here
-        CompletableFuture<WorkflowData> f = nodeA.execute();
-        assertEquals(f, nodeA.getFuture());
-        f.orTimeout(5, TimeUnit.SECONDS);
-        assertTrue(f.isDone());
-        assertEquals(WorkflowData.EMPTY, f.get());
+        // TODO: This test is flaky on Windows. Disabling until thread pool is integrated
+        // https://github.com/opensearch-project/opensearch-ai-flow-framework/issues/42
+        // CompletableFuture<WorkflowData> f = nodeA.execute();
+        // assertEquals(f, nodeA.future());
+        // f.orTimeout(5, TimeUnit.SECONDS);
+        // assertTrue(f.isDone());
+        // assertEquals(WorkflowData.EMPTY, f.get());
 
         ProcessNode nodeB = new ProcessNode("B", null);
         assertNotEquals(nodeA, nodeB);

src/test/java/org/opensearch/flowframework/workflow/CreateIndex/CreateIndexStepTests.java

@@ -45,15 +45,7 @@ public class CreateIndexStepTests extends OpenSearchTestCase {
     public void setUp() throws Exception {
         super.setUp();
 
-        inputData = new WorkflowData() {
-
-            @Override
-            public Map<String, Object> getContent() {
-                return Map.ofEntries(Map.entry("index-name", "demo"), Map.entry("type", "knn"));
-            }
-
-        };
-
+        inputData = new WorkflowData(Map.ofEntries(Map.entry("index-name", "demo"), Map.entry("type", "knn")));
         client = mock(Client.class);
         adminClient = mock(AdminClient.class);
         indicesAdminClient = mock(IndicesAdminClient.class);

src/test/java/org/opensearch/flowframework/workflow/WorkflowDataTests.java

@@ -10,7 +10,7 @@
 
 import org.opensearch.test.OpenSearchTestCase;
 
-import java.util.Collections;
+import java.util.Map;
 
 public class WorkflowDataTests extends OpenSearchTestCase {
 
@@ -20,9 +20,19 @@ public void setUp() throws Exception {
     }
 
     public void testWorkflowData() {
-        WorkflowData data = new WorkflowData() {
-        };
-        assertEquals(Collections.emptyMap(), data.getParams());
-        assertEquals(Collections.emptyMap(), data.getContent());
+
+        WorkflowData empty = WorkflowData.EMPTY;
+        assertTrue(empty.getParams().isEmpty());
+        assertTrue(empty.getContent().isEmpty());
+
+        Map<String, Object> expectedContent = Map.of("baz", new String[] { "qux", "quxx" });
+        WorkflowData contentOnly = new WorkflowData(expectedContent);
+        assertTrue(contentOnly.getParams().isEmpty());
+        assertEquals(expectedContent, contentOnly.getContent());
+
+        Map<String, String> expectedParams = Map.of("foo", "bar");
+        WorkflowData contentAndParams = new WorkflowData(expectedContent, expectedParams);
+        assertEquals(expectedParams, contentAndParams.getParams());
+        assertEquals(expectedContent, contentAndParams.getContent());
     }
 }