Added Gradle plugin scaffolding

.gitignore

@@ -5,5 +5,4 @@
 out
 *.iml
 *.ipr
-*.iws
-.shelf
+*.iws

build.gradle

@@ -15,11 +15,17 @@ repositories {
     jcenter()
 }
 
+apply from: "$rootDir/gradle/integ-test.gradle"
+apply from: "$rootDir/gradle/release.gradle"
+
 dependencies {
-    implementation "com.eclipsesource.minimal-json:minimal-json:0.9.5"
+    testImplementation 'junit:junit:4.12'
+
+    testImplementation "org.spockframework:spock-core:1.3-groovy-2.5"
+    testImplementation "cglib:cglib-nodep:3.3.0" //mocking concrete classes with spock
+    testImplementation "org.objenesis:objenesis:3.1" //as above
 
-    testImplementation "org.junit.jupiter:junit-jupiter-api:5.6.0"
-    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:5.6.0"
+    testImplementation gradleTestKit()
 }
 
 test {

gradle/integ-test.gradle

@@ -0,0 +1,22 @@
+sourceSets {
+    integTest {
+    }
+}
+
+gradlePlugin.testSourceSets(sourceSets.integTest)
+configurations.integTestImplementation.extendsFrom(configurations.testImplementation)
+
+task integTest(type: Test) {
+    testClassesDirs = sourceSets.integTest.output.classesDirs
+    classpath = sourceSets.integTest.runtimeClasspath
+}
+
+check {
+    dependsOn(tasks.integTest)
+}
+
+idea {
+    module {
+        testSourceDirs += file('src/integTest/groovy')
+    }
+}

gradle/release.gradle

@@ -0,0 +1,21 @@
+// docs: https://plugins.gradle.org/docs/publish-plugin
+gradlePlugin {
+    plugins {
+        autoVersion {
+            id = 'org.shipkit.changelog'
+            implementationClass = 'org.shipkit.changelog.ChangelogPlugin'
+        }
+    }
+}
+
+pluginBundle {
+    website = 'https://github.com/shipkit/org.shipkit.shipkit-changelog'
+    vcsUrl = 'https://github.com/shipkit/org.shipkit.shipkit-changelog.git'
+    plugins {
+        autoVersion {
+            displayName = 'Shipkit changelog plugin'
+            description = 'Generates changelog based on ticked IDs found in commit messages and GitHub pull request information'
+            tags = ['ci', 'shipkit', 'changelog']
+        }
+    }
+}

src/integTest/groovy/org/shipkit/changelog/ChangelogPluginIntegTest.groovy

@@ -0,0 +1,52 @@
+package org.shipkit.changelog
+
+import org.gradle.testkit.runner.GradleRunner
+import org.junit.Rule
+import org.junit.rules.TemporaryFolder
+import spock.lang.Specification
+
+/**
+ * Only smoke test, forever! Don't add more tests here, instead cover the complexity in lower level unit tests.
+ */
+class ChangelogPluginIntegTest extends Specification {
+
+    @Rule TemporaryFolder tmp = new TemporaryFolder()
+
+    def setup() {
+        file("settings.gradle")
+        file("build.gradle") << """
+            plugins {  id('org.shipkit.changelog')}
+        """
+    }
+
+    def "applies plugin cleanly"() {
+        given:
+        def result = run("tasks")
+
+        expect:
+        result.output.contains("Applying plugin...")
+    }
+
+    File file(String path) {
+        def f = new File(rootDir, path)
+        if (!f.exists()) {
+            f.parentFile.mkdirs()
+            f.createNewFile()
+            assert f.exists()
+        }
+        return f
+    }
+
+    File getRootDir() {
+        return tmp.root
+    }
+
+    def run(String ...args) {
+        def runner = GradleRunner.create()
+        runner.forwardOutput()
+        runner.withPluginClasspath()
+        runner.withArguments(args)
+        runner.withProjectDir(rootDir)
+        return runner.build()
+    }
+}

src/main/java/org/shipkit/changelog/ChangelogPlugin.java

@@ -0,0 +1,18 @@
+package org.shipkit.changelog;
+
+import org.gradle.api.Plugin;
+import org.gradle.api.Project;
+import org.gradle.api.logging.Logger;
+import org.gradle.api.logging.Logging;
+
+/**
+ * The plugin, ideally with zero business logic, but only the Gradle integration code
+ */
+public class ChangelogPlugin implements Plugin<Project> {
+
+    private static final Logger LOG = Logging.getLogger(ChangelogPlugin.class);
+
+    public void apply(Project project) {
+        LOG.lifecycle("Applying plugin...");
+    }
+}