Add support for build caching

Resolves #7

subprojects/documentation/src/docs/asciidoc/parts/release-history.adoc

@@ -1,5 +1,13 @@
 = Release History
 
+== 0.3.1
+
+Release date: TBA
+
+=== New Features
+
+* Build cache support ({gh-issue}7[#7])
+
 == 0.3.0
 
 Release date: 2020-08-02

subprojects/plugin/src/main/kotlin/de/benediktritter/maven/plugin/development/task/GenerateHelpMojoSourcesTask.kt

@@ -26,12 +26,10 @@ import org.codehaus.plexus.velocity.VelocityComponent
 import org.gradle.api.file.DirectoryProperty
 import org.gradle.api.file.RegularFileProperty
 import org.gradle.api.provider.Property
-import org.gradle.api.tasks.Input
-import org.gradle.api.tasks.OutputDirectory
-import org.gradle.api.tasks.OutputFile
-import org.gradle.api.tasks.TaskAction
+import org.gradle.api.tasks.*
 import java.util.*
 
+@CacheableTask
 abstract class GenerateHelpMojoSourcesTask : AbstractMavenPluginDevelopmentTask() {
 
     @get:OutputDirectory

subprojects/plugin/src/main/kotlin/de/benediktritter/maven/plugin/development/task/GenerateMavenPluginDescriptorTask.kt

@@ -39,6 +39,7 @@ import org.gradle.kotlin.dsl.get
 import org.gradle.kotlin.dsl.the
 import java.io.File
 
+@CacheableTask
 abstract class GenerateMavenPluginDescriptorTask : AbstractMavenPluginDevelopmentTask() {
 
     @get:Input

subprojects/plugin/src/test/groovy/de/benediktritter/maven/plugin/development/BuildCachingFuncTest.groovy

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2020 Benedikt Ritter
+ *
+ * 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 de.benediktritter.maven.plugin.development
+
+import org.gradle.testkit.runner.TaskOutcome
+
+class BuildCachingFuncTest extends AbstractPluginFuncTest {
+
+    def "supports build caching"() {
+        given:
+        javaMojo()
+        buildFile << "mavenPlugin.helpMojoPackage.set('org.example.help')"
+
+        and:
+        run("build", "--build-cache")
+
+        when:
+        buildDir.deleteDir()
+
+        and:
+        def result = run("build", "--build-cache")
+
+        then:
+        result.task(":generateMavenPluginHelpMojoSources").outcome == TaskOutcome.FROM_CACHE
+        result.task(":generateMavenPluginDescriptor").outcome == TaskOutcome.FROM_CACHE
+    }
+}

subprojects/plugin/src/testFixtures/groovy/de/benediktritter/maven/plugin/development/fixtures/TestProject.groovy

@@ -46,6 +46,10 @@ trait TestProject {
         file("settings.gradle")
     }
 
+    File getBuildDir() {
+        file("build")
+    }
+
     File getBuildFile() {
         file("build.gradle")
     }