[Konvert] Convert AssertJGeneratorGradlePlugin to Kotlin

Completes the Konvert from #39!

src/main/kotlin/org/assertj/generator/gradle/AssertJGeneratorGradlePlugin.kt

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2023. assertj-generator-gradle-plugin contributors.
+ *
+ * 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 org.assertj.generator.gradle
+
+import org.assertj.generator.gradle.tasks.AssertJGenerationTask
+import org.assertj.generator.gradle.tasks.config.AssertJGeneratorExtension
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.logging.Logging
+import org.gradle.api.model.ObjectFactory
+import org.gradle.api.plugins.JavaPlugin
+import org.gradle.api.plugins.JavaPluginExtension
+import org.gradle.api.tasks.SourceSet
+import org.gradle.kotlin.dsl.create
+import org.gradle.kotlin.dsl.getByType
+import org.gradle.kotlin.dsl.register
+import javax.inject.Inject
+
+/**
+ * Defines the entry point for applying the AssertJGeneration plugin
+ */
+open class AssertJGeneratorGradlePlugin @Inject internal constructor(
+  private val objects: ObjectFactory,
+) : Plugin<Project> {
+
+  override fun apply(project: Project) {
+    project.pluginManager.withPlugin("java") {
+      val assertJGeneratorConfiguration = project.configurations.create(ASSERTJ_GEN_CONFIGURATION_NAME)
+        .setVisible(false)
+        .setDescription("AssertJ Generator configuration")
+      assertJGeneratorConfiguration.defaultDependencies {
+        it.add(project.dependencies.create("org.assertj:assertj-assertions-generator:2.0.0"))
+      }
+
+      project.configurations.named(JavaPlugin.TEST_IMPLEMENTATION_CONFIGURATION_NAME) {
+        assertJGeneratorConfiguration.extendsFrom(it)
+      }
+
+      val javaPluginExtension = project.extensions.getByType<JavaPluginExtension>()
+
+      // So now we have to go through and add the properties that we want
+      javaPluginExtension.sourceSets.all { sourceSet ->
+        if (sourceSet.name == "test") return@all
+
+        // For each sourceSet we're enacting an action on each one that adds an assertJ generation task to it
+        logger.info("sourceSet: $sourceSet creating tasks")
+
+        sourceSet.extensions.create<AssertJGeneratorExtension>(
+          "assertJ",
+          objects,
+          project,
+          sourceSet,
+        )
+
+        addAndConfigureAssertJGenerate(project, javaPluginExtension, sourceSet)
+      }
+    }
+  }
+
+  private fun addAndConfigureAssertJGenerate(
+    project: Project,
+    javaPlugin: JavaPluginExtension,
+    sourceSet: SourceSet
+  ) {
+    val generateTaskName = sourceSet.getTaskName("generate", "assertJ")
+
+    logger.info("generationTask: $generateTaskName, sourceSet: $sourceSet")
+
+    // Create a new task for the source set
+    val generationTask = project.tasks.register<AssertJGenerationTask>(generateTaskName, objects, sourceSet)
+
+    javaPlugin.sourceSets.named("test").configure { sourceSet ->
+      sourceSet.java.srcDir(generationTask.flatMap { it.outputDir })
+    }
+  }
+
+  companion object {
+    const val ASSERTJ_GEN_CONFIGURATION_NAME = "assertJ"
+
+    private val logger = Logging.getLogger(AssertJGeneratorGradlePlugin::class.java)
+  }
+}