Add temporal-kotlin providing correct support for Kotlin in Async

temporal-kotlin/README.md

@@ -1,7 +1,7 @@
 # Temporal Kotlin support module
 
 This module added to classpath provides some support for Kotlin specific language features:
-   - Support for Kotlin  
+   - Support for Kotlin method references for Temporal client stubs passed into Async
 
 ## Usage
 

temporal-kotlin/build.gradle

@@ -1,15 +1,8 @@
-buildscript {
-    repositories {
-        maven {
-            url "https://plugins.gradle.org/m2/"
-        }
-    }
-}
-
 plugins {
 //    id 'org.jetbrains.kotlin.jvm' version '1.3.72'
 //    id 'org.jetbrains.kotlin.jvm' version '1.4.21'
     id 'org.jetbrains.kotlin.jvm' version '1.5.21'
+
     id 'org.jlleitschuh.gradle.ktlint' version '10.1.0'
 }
 
@@ -38,10 +31,12 @@ dependencies {
 
     implementation project(':temporal-sdk')
 
+    implementation group: 'com.fasterxml.jackson.datatype', name: 'jackson-datatype-jsr310', version: '2.12.4'
+    implementation group: 'com.fasterxml.jackson.module', name: 'jackson-module-kotlin', version: '2.12.4'
+
     testImplementation project(':temporal-testing')
+    testImplementation project(':temporal-testing-junit4')
 
-    testImplementation group: 'com.fasterxml.jackson.datatype', name: 'jackson-datatype-jsr310', version: '2.12.4'
-    testImplementation group: 'com.fasterxml.jackson.module', name: 'jackson-module-kotlin', version: '2.12.4'
     testImplementation group: 'ch.qos.logback', name: 'logback-classic', version: '1.2.5'
     testImplementation group: 'junit', name: 'junit', version: '4.13.2'
 }

temporal-kotlin/src/main/kotlin/io/temporal/common/converter/DefaultKotlinJacksonObjectMapper.kt

@@ -0,0 +1,40 @@
+/*
+ *  Copyright (C) 2020 Temporal Technologies, Inc. All Rights Reserved.
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.temporal.common.converter
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect
+import com.fasterxml.jackson.annotation.PropertyAccessor
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.SerializationFeature
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule
+import com.fasterxml.jackson.module.kotlin.KotlinModule
+
+class DefaultKotlinJacksonObjectMapper {
+  companion object {
+    fun new(): ObjectMapper {
+      val mapper = ObjectMapper()
+      mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false)
+      mapper.registerModule(JavaTimeModule())
+      mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY)
+      mapper.registerModule(KotlinModule())
+      return mapper
+    }
+  }
+}

temporal-kotlin/src/test/kotlin/io/temporal/workflow/KotlinAsyncChildWorkflowTest.kt

@@ -0,0 +1,86 @@
+/*
+ *  Copyright (C) 2020 Temporal Technologies, Inc. All Rights Reserved.
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.temporal.workflow
+
+import io.temporal.client.WorkflowClientOptions
+import io.temporal.client.WorkflowOptions
+import io.temporal.common.converter.DefaultDataConverter
+import io.temporal.common.converter.DefaultKotlinJacksonObjectMapper
+import io.temporal.common.converter.JacksonJsonPayloadConverter
+import io.temporal.internal.async.FunctionWrappingUtil
+import io.temporal.internal.sync.AsyncInternal
+import io.temporal.testing.TestWorkflowRule
+import org.junit.Assert.assertTrue
+import org.junit.Rule
+import org.junit.Test
+
+class KotlinAsyncChildWorkflowTest {
+
+  @Rule @JvmField
+  var testWorkflowRule: TestWorkflowRule = TestWorkflowRule.newBuilder()
+    .setWorkflowTypes(NaiveParentWorkflowImpl::class.java, ChildWorkflowImpl::class.java)
+    .setWorkflowClientOptions(
+      WorkflowClientOptions.newBuilder()
+        .setDataConverter(DefaultDataConverter(JacksonJsonPayloadConverter(DefaultKotlinJacksonObjectMapper.new())))
+        .build()
+    )
+    .build()
+
+  @WorkflowInterface
+  interface ChildWorkflow {
+    @WorkflowMethod
+    fun execute(): Int
+  }
+
+  class ChildWorkflowImpl : ChildWorkflow {
+    override fun execute(): Int {
+      return 0
+    }
+  }
+
+  @WorkflowInterface
+  interface NaiveParentWorkflow {
+    @WorkflowMethod
+    fun execute()
+  }
+
+  class NaiveParentWorkflowImpl : NaiveParentWorkflow {
+    override fun execute() {
+      val childWorkflow = Workflow.newChildWorkflowStub(ChildWorkflow::class.java)
+      assertTrue(
+        "This has to be true to make Async.function(childWorkflow::execute) work correctly as expected",
+        AsyncInternal.isAsync(childWorkflow::execute)
+      )
+      assertTrue(
+        "This has to be true to make Async.function(childWorkflow::execute) work correctly as expected",
+        AsyncInternal.isAsync(FunctionWrappingUtil.temporalJavaFunctionalWrapper(childWorkflow::execute))
+      )
+      Async.function(childWorkflow::execute).get()
+    }
+  }
+
+  @Test
+  fun asyncChildWorkflowTest() {
+    val client = testWorkflowRule.workflowClient
+    val options = WorkflowOptions.newBuilder().setTaskQueue(testWorkflowRule.taskQueue).build()
+    val workflowStub = client.newWorkflowStub(NaiveParentWorkflow::class.java, options)
+    workflowStub.execute()
+  }
+}

temporal-kotlin/src/test/kotlin/io/temporal/workflow/KotlinAsyncLambdaTest.kt

@@ -0,0 +1,69 @@
+/*
+ *  Copyright (C) 2020 Temporal Technologies, Inc. All Rights Reserved.
+ *
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.temporal.workflow
+
+import io.temporal.client.WorkflowClientOptions
+import io.temporal.client.WorkflowOptions
+import io.temporal.common.converter.DefaultDataConverter
+import io.temporal.common.converter.DefaultKotlinJacksonObjectMapper
+import io.temporal.common.converter.JacksonJsonPayloadConverter
+import io.temporal.testing.TestWorkflowRule
+import junit.framework.Assert.assertTrue
+import org.junit.Rule
+import org.junit.Test
+import java.util.concurrent.atomic.AtomicBoolean
+
+class KotlinAsyncLambdaTest {
+
+  companion object {
+    private val success = AtomicBoolean(false)
+  }
+
+  @Rule @JvmField
+  var testWorkflowRule: TestWorkflowRule = TestWorkflowRule.newBuilder()
+    .setWorkflowTypes(NaiveParentWorkflowImpl::class.java)
+    .setWorkflowClientOptions(
+      WorkflowClientOptions.newBuilder()
+        .setDataConverter(DefaultDataConverter(JacksonJsonPayloadConverter(DefaultKotlinJacksonObjectMapper.new())))
+        .build()
+    )
+    .build()
+
+  @WorkflowInterface
+  interface NaiveParentWorkflow {
+    @WorkflowMethod
+    fun execute()
+  }
+
+  class NaiveParentWorkflowImpl : NaiveParentWorkflow {
+    override fun execute() {
+      Async.procedure { success.set(true) }.get()
+    }
+  }
+
+  @Test
+  fun asyncChildWorkflowTest() {
+    val client = testWorkflowRule.workflowClient
+    val options = WorkflowOptions.newBuilder().setTaskQueue(testWorkflowRule.taskQueue).build()
+    val workflowStub = client.newWorkflowStub(NaiveParentWorkflow::class.java, options)
+    workflowStub.execute()
+    assertTrue(success.get())
+  }
+}

temporal-sdk/src/main/java/io/temporal/internal/async/MethodReferenceDisassembler.java

@@ -65,7 +65,8 @@ private static boolean isAsyncKotlin(Object func) {
       if (methodReferenceDisassemblyService == null) {
         throw new IllegalStateException(
             "Kotlin method reference is used with async. "
-                + "For Temporal to correctly support async invocation kotlin method references, add temporal-kotlin to classpath");
+                + "For Temporal to correctly support async invocation kotlin method references, "
+                + "add io.temporal:temporal-kotlin to classpath");
       }
 
       Object target = methodReferenceDisassemblyService.getMethodReferenceTarget(func);

temporal-sdk/src/main/java/io/temporal/internal/async/spi/MethodReferenceDisassemblyService.java

@@ -22,6 +22,11 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+/**
+ * Provides language specific functionality to disassemble method references that could be passed
+ * from different languages into temporal code and extract target from them, which is required for
+ * correct working of {@link io.temporal.workflow.Async}
+ */
 public interface MethodReferenceDisassemblyService {
   String KOTLIN = "kotlin";
 
@@ -33,5 +38,6 @@ public interface MethodReferenceDisassemblyService {
   @Nullable
   Object getMethodReferenceTarget(@Nonnull Object methodReference);
 
+  /** @return language this service provides an extension or implementation for */
   String getLanguageName();
 }