feat: add sub worflows run on FuncDSL #1295

experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncDoTaskBuilder.java

@@ -19,6 +19,7 @@
 import io.serverlessworkflow.fluent.func.spi.FuncDoFluent;
 import io.serverlessworkflow.fluent.func.spi.FuncTaskTransformations;
 import io.serverlessworkflow.fluent.spec.BaseDoTaskBuilder;
+import io.serverlessworkflow.fluent.spec.WorkflowTaskBuilder;
 import java.util.function.Consumer;
 
 public class FuncDoTaskBuilder extends BaseDoTaskBuilder<FuncDoTaskBuilder, FuncTaskItemListBuilder>
@@ -103,6 +104,24 @@ public FuncDoTaskBuilder openapi(
     return this;
   }
 
+  @Override
+  public FuncDoTaskBuilder workflow(String name, Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    this.listBuilder().workflow(name, itemsConfigurer);
+    return this;
+  }
+
+  @Override
+  public FuncDoTaskBuilder subflow(String name, Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    this.listBuilder().subflow(name, itemsConfigurer);
+    return this;
+  }
+
+  @Override
+  public FuncDoTaskBuilder subflow(Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    this.listBuilder().subflow(itemsConfigurer);
+    return this;
+  }
+
   @Override
   public FuncDoTaskBuilder tryCatch(String name, Consumer<FuncTryTaskBuilder> itemsConfigurer) {
     this.listBuilder().tryCatch(name, itemsConfigurer);

experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncTaskItemListBuilder.java

@@ -22,6 +22,8 @@
 import io.serverlessworkflow.api.types.TaskItem;
 import io.serverlessworkflow.fluent.func.spi.FuncDoFluent;
 import io.serverlessworkflow.fluent.spec.BaseTaskItemListBuilder;
+import io.serverlessworkflow.fluent.spec.TaskItemListBuilder;
+import io.serverlessworkflow.fluent.spec.WorkflowTaskBuilder;
 import java.util.List;
 import java.util.function.Consumer;
 
@@ -165,6 +167,46 @@ public FuncTaskItemListBuilder openapi(
     return this.addTaskItem(new TaskItem(name, task));
   }
 
+  @Override
+  public FuncTaskItemListBuilder workflow(
+      String name, Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    return this.addDelegatedWorkflow(name, itemsConfigurer, TYPE_WORKFLOW);
+  }
+
+  @Override
+  public FuncTaskItemListBuilder workflow(Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    return this.workflow(null, itemsConfigurer);
+  }
+
+  @Override
+  public FuncTaskItemListBuilder subflow(
+      String name, Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    return this.addDelegatedWorkflow(name, itemsConfigurer, TYPE_WORKFLOW);
+  }
+
+  @Override
+  public FuncTaskItemListBuilder subflow(Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    return this.subflow(null, itemsConfigurer);
+  }
+
+  private FuncTaskItemListBuilder addDelegatedWorkflow(
+      String name, Consumer<WorkflowTaskBuilder> itemsConfigurer, String delegateType) {
+    name = this.defaultNameAndRequireConfig(name, itemsConfigurer, delegateType);
+    // Preserve the original offset when delegating to avoid duplicate task names
+    // across appended .tasks(...) blocks
+    final int effectiveOffset = this.getOffset() + this.mutableList().size();
+    final TaskItemListBuilder delegate = new TaskItemListBuilder(effectiveOffset);
+    delegate.workflow(name, itemsConfigurer);
+    final List<TaskItem> taskItems = delegate.build();
+    if (taskItems.size() != 1) {
+      throw new IllegalStateException(
+          String.format(
+              "Expected %s delegate '%s' to build exactly 1 TaskItem, but got %d",
+              delegateType, name, taskItems.size()));
+    }
+    return addTaskItem(taskItems.get(0));
+  }
+
   @Override
   public FuncTaskItemListBuilder tryCatch(
       String name, Consumer<FuncTryTaskBuilder> itemsConfigurer) {

experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/FuncDSL.java

@@ -40,9 +40,12 @@
 import io.serverlessworkflow.fluent.spec.EventFilterBuilder;
 import io.serverlessworkflow.fluent.spec.ScheduleBuilder;
 import io.serverlessworkflow.fluent.spec.TimeoutBuilder;
+import io.serverlessworkflow.fluent.spec.WorkflowTaskBuilder;
 import io.serverlessworkflow.fluent.spec.configurers.AuthenticationConfigurer;
+import io.serverlessworkflow.fluent.spec.configurers.WorkflowConfigurer;
 import io.serverlessworkflow.fluent.spec.dsl.DSL;
 import io.serverlessworkflow.fluent.spec.dsl.UseSpec;
+import io.serverlessworkflow.fluent.spec.dsl.WorkflowSpec;
 import io.serverlessworkflow.impl.TaskContextData;
 import io.serverlessworkflow.impl.WorkflowContextData;
 import java.net.URI;
@@ -1116,6 +1119,107 @@ public static FuncTaskConfigurer set(Map<String, Object> map) {
     return list -> list.set(s -> s.expr(map));
   }
 
+  /**
+   * Create a {@link FuncTaskConfigurer} that adds a sub-workflow call task using a {@link
+   * WorkflowConfigurer}.
+   *
+   * <pre>{@code
+   * tasks(
+   *     subflow(
+   *         workflow("org.acme", "sub-workflow", "0.1.0")
+   *             .input("id", 99)
+   *             .await(false)
+   *     )
+   * );
+   * }</pre>
+   *
+   * @param configurer nested workflow configurer
+   * @return a {@link FuncTaskConfigurer} that adds a workflow task to the tasks list
+   */
+  public static FuncTaskConfigurer subflow(WorkflowConfigurer configurer) {
+    Objects.requireNonNull(configurer, "configurer");
+    return list -> list.subflow(configurer);
+  }
+
+  /**
+   * Create a {@link FuncTaskConfigurer} that adds a named sub-workflow call task.
+   *
+   * @param name task name
+   * @param configurer nested workflow configurer
+   * @return a {@link FuncTaskConfigurer} that adds a workflow task to the tasks list
+   */
+  public static FuncTaskConfigurer subflow(String name, Consumer<WorkflowTaskBuilder> configurer) {
+    Objects.requireNonNull(name, "name");
+    Objects.requireNonNull(configurer, "configurer");
+    return list -> list.subflow(name, configurer);
+  }
+
+  /**
+   * Create a {@link FuncTaskConfigurer} that adds an unnamed sub-workflow call task.
+   *
+   * @param configurer nested workflow configurer
+   * @return a {@link FuncTaskConfigurer} that adds a workflow task to the tasks list
+   */
+  public static FuncTaskConfigurer subflow(Consumer<WorkflowTaskBuilder> configurer) {
+    Objects.requireNonNull(configurer, "configurer");
+    return list -> list.subflow(configurer);
+  }
+
+  /**
+   * Alias for {@link #subflow(WorkflowConfigurer)}.
+   *
+   * @param configurer nested workflow configurer
+   * @return a {@link FuncTaskConfigurer} that adds a workflow task to the tasks list
+   */
+  public static FuncTaskConfigurer workflowTask(WorkflowConfigurer configurer) {
+    return subflow(configurer);
+  }
+
+  /**
+   * Create a {@link FuncTaskConfigurer} that adds a workflow subflow task.
+   *
+   * @param configurer configurer for the nested workflow task
+   * @return a {@link FuncTaskConfigurer} that adds a workflow task to the tasks list
+   * @deprecated use {@link #subflow(WorkflowConfigurer)} to avoid ambiguity with spec-side factory
+   *     methods
+   */
+  @Deprecated
+  public static FuncTaskConfigurer workflow(WorkflowConfigurer configurer) {
+    return subflow(configurer);
+  }
+
+  /**
+   * Create a new {@link WorkflowSpec} to be used as a factory for workflow definitions.
+   *
+   * @param namespace workflow namespace
+   * @param name workflow name
+   * @param version workflow version
+   * @return a new {@link WorkflowSpec} instance
+   */
+  public static WorkflowSpec workflow(String namespace, String name, String version) {
+    return DSL.workflow(namespace, name, version);
+  }
+
+  /**
+   * Create a new {@link WorkflowSpec} to be used as a factory for workflow definitions.
+   *
+   * @param namespace workflow namespace
+   * @param name workflow name
+   * @return a new {@link WorkflowSpec} instance
+   */
+  public static WorkflowSpec workflow(String namespace, String name) {
+    return DSL.workflow(namespace, name);
+  }
+
+  /**
+   * Create a new {@link WorkflowSpec} to be used as a factory for workflow definitions.
+   *
+   * @return a new {@link WorkflowSpec} instance
+   */
+  public static WorkflowSpec workflow() {
+    return DSL.workflow();
+  }
+
   // ---------------------------------------------------------------------------
   // HTTP / OpenAPI
   // ---------------------------------------------------------------------------

experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/spi/FuncDoFluent.java

@@ -26,6 +26,7 @@
 import io.serverlessworkflow.fluent.func.FuncSetTaskBuilder;
 import io.serverlessworkflow.fluent.func.FuncSwitchTaskBuilder;
 import io.serverlessworkflow.fluent.func.FuncTryTaskBuilder;
+import io.serverlessworkflow.fluent.spec.WorkflowTaskBuilder;
 import io.serverlessworkflow.fluent.spec.spi.CallHttpFluent;
 import io.serverlessworkflow.fluent.spec.spi.CallOpenAPIFluent;
 import io.serverlessworkflow.fluent.spec.spi.EmitFluent;
@@ -36,6 +37,8 @@
 import io.serverlessworkflow.fluent.spec.spi.SetFluent;
 import io.serverlessworkflow.fluent.spec.spi.SwitchFluent;
 import io.serverlessworkflow.fluent.spec.spi.TryCatchFluent;
+import io.serverlessworkflow.fluent.spec.spi.WorkflowFluent;
+import java.util.function.Consumer;
 
 public interface FuncDoFluent<SELF extends FuncDoFluent<SELF>>
     extends SetFluent<FuncSetTaskBuilder, SELF>,
@@ -48,4 +51,14 @@ public interface FuncDoFluent<SELF extends FuncDoFluent<SELF>>
         TryCatchFluent<FuncTryTaskBuilder, SELF>,
         CallFnFluent<FuncCallTaskBuilder, SELF>,
         CallHttpFluent<FuncCallHttpTaskBuilder, SELF>,
-        CallOpenAPIFluent<FuncCallOpenAPITaskBuilder, SELF> {}
+        CallOpenAPIFluent<FuncCallOpenAPITaskBuilder, SELF>,
+        WorkflowFluent<WorkflowTaskBuilder, SELF> {
+
+  default SELF subflow(String name, Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    return this.workflow(name, itemsConfigurer);
+  }
+
+  default SELF subflow(Consumer<WorkflowTaskBuilder> itemsConfigurer) {
+    return this.workflow(itemsConfigurer);
+  }
+}