[Fix #1121] Ensuring service priority order

Signed-off-by: fjtirado <ftirados@redhat.com>

Author: fjtirado

impl/core/pom.xml

@@ -33,5 +33,10 @@
             <artifactId>junit-jupiter-engine</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 </project>

impl/core/src/main/java/io/serverlessworkflow/impl/FunctionReader.java

@@ -19,4 +19,4 @@
 import io.serverlessworkflow.impl.resources.ExternalResourceHandler;
 import java.util.function.Function;
 
-public interface FunctionReader extends Function<ExternalResourceHandler, Task> {}
+public interface FunctionReader extends Function<ExternalResourceHandler, Task>, ServicePriority {}

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowApplication.java

@@ -15,6 +15,7 @@
  */
 package io.serverlessworkflow.impl;
 
+import static io.serverlessworkflow.impl.WorkflowUtils.loadFirst;
 import static io.serverlessworkflow.impl.WorkflowUtils.safeClose;
 
 import io.serverlessworkflow.api.types.SchemaInline;
@@ -305,8 +306,7 @@ public Builder withDefaultCatalogURI(URI defaultCatalogURI) {
     public WorkflowApplication build() {
       if (modelFactory == null) {
         modelFactory =
-            ServiceLoader.load(WorkflowModelFactory.class)
-                .findFirst()
+            loadFirst(WorkflowModelFactory.class)
                 .orElseThrow(
                     () ->
                         new IllegalStateException(
@@ -318,21 +318,17 @@ public WorkflowApplication build() {
       ServiceLoader.load(ExpressionFactory.class).forEach(exprFactories::add);
       if (schemaValidatorFactory == null) {
         schemaValidatorFactory =
-            ServiceLoader.load(SchemaValidatorFactory.class)
-                .findFirst()
+            loadFirst(SchemaValidatorFactory.class)
                 .orElseGet(() -> EmptySchemaValidatorHolder.instance);
       }
       if (taskFactory == null) {
         taskFactory =
-            ServiceLoader.load(TaskExecutorFactory.class)
-                .findFirst()
-                .orElseGet(() -> DefaultTaskExecutorFactory.get());
+            loadFirst(TaskExecutorFactory.class).orElseGet(() -> DefaultTaskExecutorFactory.get());
       }
       ServiceLoader.load(EventPublisher.class).forEach(e -> eventPublishers.add(e));
       if (eventConsumer == null) {
         eventConsumer =
-            ServiceLoader.load(EventConsumer.class)
-                .findFirst()
+            loadFirst(EventConsumer.class)
                 .orElseGet(
                     () -> {
                       InMemoryEvents inMemory = new InMemoryEvents(executorFactory);
@@ -353,18 +349,14 @@ public WorkflowApplication build() {
 
       if (configManager == null) {
         configManager =
-            ServiceLoader.load(ConfigManager.class)
-                .findFirst()
-                .orElseGet(() -> new SystemPropertyConfigManager());
+            loadFirst(ConfigManager.class).orElseGet(() -> new SystemPropertyConfigManager());
       }
       if (secretManager == null) {
         secretManager =
-            ServiceLoader.load(SecretManager.class)
-                .findFirst()
-                .orElseGet(() -> new ConfigSecretManager(configManager));
+            loadFirst(SecretManager.class).orElseGet(() -> new ConfigSecretManager(configManager));
       }
-      templateResolver = ServiceLoader.load(URITemplateResolver.class).findFirst();
-      functionReader = ServiceLoader.load(FunctionReader.class).findFirst();
+      templateResolver = loadFirst(URITemplateResolver.class);
+      functionReader = loadFirst(FunctionReader.class);
       if (defaultCatalogURI == null) {
         defaultCatalogURI = URI.create("https://github.com/serverlessworkflow/catalog");
       }

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowUtils.java

@@ -39,6 +39,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.ServiceLoader;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -304,4 +305,11 @@ public static WorkflowValueResolver<URI> getURISupplier(
     }
     throw new IllegalArgumentException("Invalid uritemplate definition " + template);
   }
+
+  public static <T extends ServicePriority> Optional<T> loadFirst(Class<T> serviceClass) {
+    return ServiceLoader.load(serviceClass).stream()
+        .map(ServiceLoader.Provider::get)
+        .sorted()
+        .findFirst();
+  }
 }

impl/core/src/main/java/io/serverlessworkflow/impl/events/EventConsumer.java

@@ -17,12 +17,13 @@
 
 import io.cloudevents.CloudEvent;
 import io.serverlessworkflow.api.types.EventFilter;
+import io.serverlessworkflow.impl.ServicePriority;
 import io.serverlessworkflow.impl.WorkflowApplication;
 import java.util.Collection;
 import java.util.function.Consumer;
 
 public interface EventConsumer<T extends EventRegistration, V extends EventRegistrationBuilder>
-    extends AutoCloseable {
+    extends AutoCloseable, ServicePriority {
 
   V listen(EventFilter filter, WorkflowApplication workflowApplication);
 

impl/core/src/main/java/io/serverlessworkflow/impl/executors/RunScriptExecutorBuilder.java

@@ -68,6 +68,7 @@ public CallableTask build(RunScript taskConfiguration, WorkflowDefinition defini
         ServiceLoader.load(ScriptRunner.class).stream()
             .map(ServiceLoader.Provider::get)
             .filter(s -> s.identifier().equals(language))
+            .sorted()
             .findFirst()
             .orElseThrow(
                 () ->

impl/core/src/main/java/io/serverlessworkflow/impl/executors/RunTaskExecutor.java

@@ -44,6 +44,7 @@ protected RunTaskExecutorBuilder(
           runnables.stream()
               .map(Provider::get)
               .filter(r -> r.accept(config.getClass()))
+              .sorted()
               .findFirst()
               .map(r -> r.build(config, definition))
               .orElseThrow(

impl/core/src/main/java/io/serverlessworkflow/impl/executors/RunnableTaskBuilder.java

@@ -16,9 +16,10 @@
 package io.serverlessworkflow.impl.executors;
 
 import io.serverlessworkflow.api.types.RunTaskConfiguration;
+import io.serverlessworkflow.impl.ServicePriority;
 import io.serverlessworkflow.impl.WorkflowDefinition;
 
-public interface RunnableTaskBuilder<T extends RunTaskConfiguration> {
+public interface RunnableTaskBuilder<T extends RunTaskConfiguration> extends ServicePriority {
   boolean accept(Class<? extends RunTaskConfiguration> clazz);
 
   CallableTask build(T taskConfiguration, WorkflowDefinition definition);

impl/core/src/main/java/io/serverlessworkflow/impl/resources/URITemplateResolver.java

@@ -15,12 +15,13 @@
  */
 package io.serverlessworkflow.impl.resources;
 
+import io.serverlessworkflow.impl.ServicePriority;
 import io.serverlessworkflow.impl.TaskContext;
 import io.serverlessworkflow.impl.WorkflowContext;
 import io.serverlessworkflow.impl.WorkflowModel;
 import java.net.URI;
 
-public interface URITemplateResolver {
+public interface URITemplateResolver extends ServicePriority {
   URI resolveTemplates(
       String uri, WorkflowContext workflowContext, TaskContext taskContext, WorkflowModel model);
 }

impl/core/src/test/java/io/serverlessworkflow/impl/LowestPriority.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020-Present The Serverless Workflow Specification Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.serverlessworkflow.impl;
+
+public class LowestPriority implements ServicePriority {
+  public int priority() {
+    return DEFAULT_PRIORITY + 1;
+  }
+}