Gradle lazy Exec-Task configuration - kotlin

I'm running into a problem when configuring an Exec-Task using an Extension-Property.
Problem
The configuration of my Exec-Task relies on a String-Property that is defined in an extension. Unfortunately, the property is not set yet, when configuring the Exec-Task. This leads to an TaskCreationException:
Could not create task ':myTask'.
org.gradle.api.internal.tasks.DefaultTaskContainer$TaskCreationException: Could not create task ':myTask'.
...
Caused by: org.gradle.api.internal.provider.MissingValueException: Cannot query the value of extension 'myConfig' property 'command' because it has no value available.
at org.gradle.api.internal.provider.AbstractMinimalProvider.get(AbstractMinimalProvider.java:86)
Example
abstract class ConfigExtension() {
abstract val command: Property<String>
}
class MyGradlePlugin : Plugin<Project> {
override fun apply(project: Project) {
val myConfig = project.extensions.create(
"myConfig",
ConfigExtension::class.java
)
val myTask = project.tasks.register(
"myTask",
Exec::class.java
) {
it.commandLine(myConfig.command.get())
}
}
}
The problem seems to be the myConfig.command.get() which circumvents the lazy evaluation.
Test
#Test fun `plugin registers task`() {
// Create a test project and apply the plugin
val project = ProjectBuilder.builder().build()
project.plugins.apply("com.example.plugin")
// Verify the result
assertNotNull(project.tasks.findByName("myTask"))
}
Question
Is there a way to configure the commandLine-Value in a lazy manner like gradle tasks should be configured? [1] [2]

Related

Is it possible to disable inlining of value classes in Kotlin?

Goal
I would like to globally disable inlining of #JvmInline value class classes via a compiler flag or something similar. I would want to do this when running unit tests but not in production.
Motivation
I would like to use mockk with value classes.
I want to write a unit test that looks like this:
#JvmInline
value class Example(private val inner: Int)
class ExampleProvider {
fun getExample(): Example = TODO()
}
#Test
fun testMethod() {
val mockExample = mockk<Example>()
val mockProvider = mockk<ExampleProvider> {
every { getExample() } returns mockExample
}
Assert.assertEquals(mockExample, mockProvider.getExample())
}
This code fails with the following exception:
no answer found for: Example(#4).unbox-impl()
I think that if I were able to disable class inlining that this would no longer be an issue.

How to access `JavaToolchainSpec` from within custom Gradle task

According to "Toolchains for plugin authors" it should be possible to access the configured JavaToolchainSpec from within a custom task. I try to use this approach within a custom plugin which creates a task based on the presence of the JavaPlugin and queries the configured languageVersion property. Here is a minimal example.
build.gradle
plugins {
id 'application'
id 'com.example.myplugin'
}
...
java {
toolchain {
languageVersion.set(JavaLanguageVersion.of(17))
}
}
MyPlugin.kt
class MyPlugin : Plugin<Project> {
override fun apply(target: Project) {
target.plugins.withType<JavaPlugin> {
target.tasks.create<MyTask>("mytask")
}
}
}
MyTask.kt
abstract class MyTask : DefaultTask() {
init {
val extension = project.extensions.getByType<JavaPluginExtension>();
val languageVersion = extension.toolchain.languageVersion.get();
...
}
}
Once Gradle creates MyTask and the languageVersion property is queried, the build fails with the following error.
Cannot query the value of property 'languageVersion' because it has no value available.
My guess is that I am accessing the extension too early and it has not set its values at this time. My question now is if there is a way to wire up the configured properties (ideally with lazy mechanisms) with the task.
apparently you have to configure the toolchain object in the java plugin extension to be able to use JavaToolchainService, using something like:
java {
toolchain {
languageVersion = JavaLanguageVersion.of(11)
}
}
if you don't do that Gradle will defaults to the current JVM and the whole toolchain API will be unavailable (leaving you with the error you reported)

How to apply a Rule to all test cases in a AndroidJUnitRunner?

I'm trying to apply a TestWatcher as a rule across all my test cases run by a particular runner.
MetadataCollector:
class MetadataCollector : TestWatcher() { ... }
TestRunner:
class TestRunner : AndroidJUnitRunner() {
override fun onCreate(arguments: Bundle?) {
super.onCreate(arguments)
}
override fun newApplication(cl: ClassLoader?, className: String?, context: Context?): Application {
return super.newApplication(cl, TestApplication::class.java.name, context)
}
}
All of my test classes currently require MetadataCollector() to be initialized as a Rule:
Test Class:
#JvmField #Rule val collector = MetadataCollector()
Is there a way I can create an instance of this rule automatically to each test case from the runner? Ideally, this is to avoid duplicating this #Rule creation in every single Test Class.
I am unfortunately stuck with JUnit 4 at the moment. :(
There is a better way to do this, by injecting an instance of RunListener into your test runner. In your gradle config, you need to:
defaultConfig.testInstrumentationRunner = "com.mypackage.MyTestRunnerClassName"
defaultConfig.testInstrumentationRunnerArgument("listener", "com.mypackage.MyRunListenerClassName")
And in code, create a RunListenerClassName to implement the corresponding hooks
class MyRunListener : RunListener() {
// impl
}

how to configure build.gradle.kts to fix error "Duplicate JVM class name generated from: package-fragment"

I'm trying to follow this tutorial https://dev.to/tagmg/step-by-step-guide-to-building-web-api-with-kotlin-and-dropwizard and am instead writing my gradle.build file in Kotlin's DSL and am finding there is no direct mapping from Groovy to Kotlin and I'm now getting this error when running ./gradlew run:
(4, 1): Duplicate JVM class name 'dropwizard/tut/AppKt' generated from: package-fragment dropwizard.tut, package-fragment dropwizard.tut
plugins {
// Apply the Kotlin JVM plugin to add support for Kotlin on the JVM.
id("org.jetbrains.kotlin.jvm").version("1.3.31")
// Apply the application plugin to add support for building a CLI application.
application
}
repositories {
// Use jcenter for resolving dependencies.
// You can declare any Maven/Ivy/file repository here.
mavenCentral()
jcenter()
}
dependencies {
// Use the Kotlin JDK 8 standard library.
implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
// Use the Kotlin test library.
testImplementation("org.jetbrains.kotlin:kotlin-test")
// Use the Kotlin JUnit integration.
testImplementation("org.jetbrains.kotlin:kotlin-test-junit")
compile("io.dropwizard:dropwizard-core:1.3.14")
}
application {
// Define the main class for the application
mainClassName = "dropwizard.tut.AppKt"
}
tasks.withType<Jar> {
manifest {
attributes["Main-Class"] = application.mainClassName
}
from({
configurations.runtimeClasspath.get().filter { it.name.endsWith("jar") }.map { zipTree(it) }
})
}
tasks.named<JavaExec>("run") {
args("server", "config/local.yaml")
}
I cannot tell (yet) why this happens but to work around it add #file:JvmName("SomethingUnique") to your JVM file. Note that renaming the file will not help and lead to the same error. Only changing the output name will resolve it.
The JVM only knows how to load classes, so the Kotlin-to-JVM compiler generates classes to hold top-level val or fun declarations.
When you have two similarly named files
// src/commonMain/kotlin/com/example/Foo.kt
package com.example
val a = 1
and
// src/jvmMain/kotlin/com/example/Foo.kt
package com.example
val b = 2
the kotlin-to-JVM compiler generates
package com.example;
public class FooKt {
public static final int a = 1;
}
and
public com.example;
public class FooKt {
public static final int b = 2;
}
Obviously, these two files can't coexist in the same JVM ClassLoader, hence the error message.
Solutions involve:
As #Fleshgrinder noted, adding a file-level JvmName annotation to at least one to override the derived name, FooKt.
Renaming files to be different where possible.
Moving top-level val and fun declarations from those files into other files so Kotlin does not need to create the FooKt class.
Moving top-level val and fun declarations into objects or companion objects.

How to create a TestContainers base test class in Kotlin with JUnit 5

I am trying to use Neo4j TestContainers with Kotlin, Spring Data Neo4j, Spring Boot and JUnit 5. I have a lot of tests that require to use the test container. Ideally, I would like to avoid copying the container definition and configuration in each test class.
Currently I have something like:
#Testcontainers
#DataNeo4jTest
#Import(Neo4jConfiguration::class, Neo4jTestConfiguration::class)
class ContainerTest(#Autowired private val repository: XYZRepository) {
companion object {
const val IMAGE_NAME = "neo4j"
const val TAG_NAME = "3.5.5"
#Container
#JvmStatic
val databaseServer: KtNeo4jContainer = KtNeo4jContainer("$IMAGE_NAME:$TAG_NAME")
.withoutAuthentication()
}
#TestConfiguration
internal class Config {
#Bean
fun configuration(): Configuration = Configuration.Builder()
.uri(databaseServer.getBoltUrl())
.build()
}
#Test
#DisplayName("Create xyz")
fun testCreateXYZ() {
// ...
}
}
class KtNeo4jContainer(val imageName: String) : Neo4jContainer<KtNeo4jContainer>(imageName)
How can I extract the databaseServer definition and the #TestConfiguration? I tried different ways of creating a base class and having the ContainerTest extend it, but it is not working. From what I understand, static attriubutes are not inherited in Kotlin.
Below my solution for sharing same container between tests.
#Testcontainers
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
abstract class IntegrationTest {
companion object {
#JvmStatic
private val mongoDBContainer = MongoDBContainer(DockerImageName.parse("mongo:4.0.10"))
.waitingFor(HostPortWaitStrategy())
#BeforeAll
#JvmStatic
fun beforeAll() {
mongoDBContainer.start()
}
#JvmStatic
#DynamicPropertySource
fun registerDynamicProperties(registry: DynamicPropertyRegistry) {
registry.add("spring.data.mongodb.host", mongoDBContainer::getHost)
registry.add("spring.data.mongodb.port", mongoDBContainer::getFirstMappedPort)
}
}
}
The key here is to not use #Container annotation as it will close just created container after your first test subclass executes all tests.
Method start() in beforeAll() initialize container only once (upon first subclass test execution), then does nothing while container is running.
By theory we shouldn't have to do this hack, based on:
https://www.testcontainers.org/test_framework_integration/junit_5/
...container that is static should not be closed until all of tests of all subclasses are finished, but it's not working that way and I don't know why. Would be nice to have some answer on that :).
I've had the same issue (making Spring Boot + Kotlin + Testcontainers work together) and after searching the web for (quite) a while I found this nice solution: https://github.com/larmic/testcontainers-junit5. You'll just have to adopt it to your database.
I faced very similar issue in Kotlin and spring boot 2.4.0.
The way you can reuse one testcontainer configuration can be achieved through initializers, e.g.:
https://dev.to/silaev/the-testcontainers-mongodb-module-and-spring-data-mongodb-in-action-53ng or https://nirajsonawane.github.io/2019/12/25/Testcontainers-With-Spring-Boot-For-Integration-Testing/ (java versions)
I wanted to use also new approach of having dynamicProperties and it worked out of a boxed in java. In Kotlin I made sth like this (I wasn't able to make #Testcontainer annotations working for some reason). It's not very elegant but pretty simple solution that worked for me:
MongoContainerConfig class:
import org.testcontainers.containers.MongoDBContainer
class MongoContainerConfig {
companion object {
#JvmStatic
val mongoDBContainer = MongoDBContainer("mongo:4.4.2")
}
init {
mongoDBContainer.start()
}
}
Test class:
#SpringBootTest(
classes = [MongoContainerConfig::class]
)
internal class SomeTest {
companion object {
#JvmStatic
#DynamicPropertySource
fun setProperties(registry: DynamicPropertyRegistry) {
registry.add("mongodb.uri") {
MongoContainerConfig.mongoDBContainer.replicaSetUrl
}
}
}
Disadvantage is this block with properties in every test class what suggests that maybe approach with initializers is desired here.