Introduce IntegrationSpec

- Consolidate the GradleTestKit setup in one place
- Add `testGradle<ID>` rule so we can re-use our GradleTestKit specs to
  verify behavior works on all supported versions of Gradle on each
  build
- Exclude Gradle 4.10.3 from running on Java 11 (Gradle 5.0 is required)
- Run all tests against the last major and each minor of the current
  major

build.gradle

@@ -85,6 +85,22 @@ signing {
     sign publishing.publications.pluginMaven
 }
 
+tasks.addRule("Pattern: testGradle<ID>") { String taskName ->
+    tasks.register(taskName, Test) { Test t ->
+        def gradleVersion = taskName - 'testGradle'
+        t.systemProperty 'gradle.under.test', gradleVersion
+        t.useJUnit { JUnitOptions o ->
+            o.includeCategories('org.jenkinsci.gradle.plugins.jpi.UsesGradleTestKit')
+        }
+        t.onlyIf {
+            gradleVersion.startsWith('4') && System.getProperty('java.specification.version') == '1.8' ||
+                    gradleVersion.startsWith('5')
+        }
+    }
+}
+
+check.dependsOn(['4.10.3', '5.0', '5.1.1', '5.2.1'].collect { tasks.named("testGradle$it") })
+
 tasks.withType(Test).configureEach {
     testLogging {
         exceptionFormat = 'full'

src/test/groovy/org/jenkinsci/gradle/plugins/jpi/AbstractManifestIntegrationSpec.groovy

@@ -2,18 +2,12 @@ package org.jenkinsci.gradle.plugins.jpi
 
 import groovy.transform.CompileStatic
 import org.gradle.testkit.runner.BuildResult
-import org.gradle.testkit.runner.GradleRunner
 import org.gradle.testkit.runner.TaskOutcome
-import org.junit.Rule
-import org.junit.rules.TemporaryFolder
-import spock.lang.Specification
 import spock.lang.Unroll
 
 import java.util.jar.JarInputStream
 
-abstract class AbstractManifestIntegrationSpec extends Specification {
-    @Rule
-    protected final TemporaryFolder projectDir = new TemporaryFolder()
+abstract class AbstractManifestIntegrationSpec extends IntegrationSpec {
     protected final String projectName = TestDataGenerator.generateName()
     protected final String projectVersion = TestDataGenerator.generateVersion()
     protected File settings
@@ -411,9 +405,7 @@ abstract class AbstractManifestIntegrationSpec extends Specification {
         if (overrideVersion) {
             args.add('-Pversion=' + overrideVersion)
         }
-        GradleRunner.create()
-                .withPluginClasspath()
-                .withProjectDir(projectDir.root)
+        gradleRunner()
                 .withArguments(args)
                 .build()
     }

src/test/groovy/org/jenkinsci/gradle/plugins/jpi/AddedDependenciesIntegrationSpec.groovy

@@ -1,15 +1,9 @@
 package org.jenkinsci.gradle.plugins.jpi
 
 import groovy.json.JsonSlurper
-import org.gradle.testkit.runner.GradleRunner
 import org.gradle.testkit.runner.TaskOutcome
-import org.junit.Rule
-import org.junit.rules.TemporaryFolder
-import spock.lang.Specification
 
-class AddedDependenciesIntegrationSpec extends Specification {
-    @Rule
-    private final TemporaryFolder projectDir = new TemporaryFolder()
+class AddedDependenciesIntegrationSpec extends IntegrationSpec {
     private final String projectName = TestDataGenerator.generateName()
     private File settings
     private File build
@@ -36,9 +30,7 @@ class AddedDependenciesIntegrationSpec extends Specification {
             '''.stripIndent()
 
         when:
-        def result = GradleRunner.create()
-                .withProjectDir(projectDir.root)
-                .withPluginClasspath()
+        def result = gradleRunner()
                 .withArguments('processTestResources', '--stacktrace')
                 .build()
 
@@ -82,9 +74,7 @@ class AddedDependenciesIntegrationSpec extends Specification {
             '''.stripIndent()
 
         when:
-        GradleRunner.create()
-                .withProjectDir(projectDir.root)
-                .withPluginClasspath()
+        gradleRunner()
                 .withArguments('writeAllResolvedDependencies')
                 .build()
         def resolutionJson = new File(projectDir.root, 'build/resolved-dependencies.json')

src/test/groovy/org/jenkinsci/gradle/plugins/jpi/IntegrationSpec.groovy

@@ -0,0 +1,25 @@
+package org.jenkinsci.gradle.plugins.jpi
+
+import groovy.transform.CompileStatic
+import org.gradle.testkit.runner.GradleRunner
+import org.junit.Rule
+import org.junit.experimental.categories.Category
+import org.junit.rules.TemporaryFolder
+import spock.lang.Specification
+
+@CompileStatic
+@Category(UsesGradleTestKit)
+class IntegrationSpec extends Specification {
+    @Rule
+    protected final TemporaryFolder projectDir = new TemporaryFolder()
+
+    protected GradleRunner gradleRunner() {
+        def runner = GradleRunner.create()
+                .withPluginClasspath()
+                .withProjectDir(projectDir.root)
+        if (System.getProperty('gradle.under.test')) {
+            return runner.withGradleVersion(System.getProperty('gradle.under.test'))
+        }
+        runner
+    }
+}

src/test/groovy/org/jenkinsci/gradle/plugins/jpi/JpiLocalizerTaskIntegrationSpec.groovy

@@ -1,54 +1,44 @@
 package org.jenkinsci.gradle.plugins.jpi
 
-import org.gradle.testkit.runner.GradleRunner
 import org.gradle.testkit.runner.TaskOutcome
-import org.junit.Rule
-import org.junit.rules.TemporaryFolder
-import spock.lang.Specification
 
-class JpiLocalizerTaskIntegrationSpec extends Specification {
-    @Rule
-    final TemporaryFolder project = new TemporaryFolder()
+class JpiLocalizerTaskIntegrationSpec extends IntegrationSpec {
 
     def 'single-module project should be able to run LocalizerTask'() {
         given:
-        project.newFile('build.gradle') << "plugins { id 'org.jenkins-ci.jpi' }"
-        project.newFolder('src', 'main', 'resources')
-        project.newFile('src/main/resources/Messages.properties') << 'key1=value1\nkey2=value2'
+        projectDir.newFile('build.gradle') << "plugins { id 'org.jenkins-ci.jpi' }"
+        projectDir.newFolder('src', 'main', 'resources')
+        projectDir.newFile('src/main/resources/Messages.properties') << 'key1=value1\nkey2=value2'
 
         when:
-        def result = GradleRunner.create()
-                .withProjectDir(project.root)
-                .withPluginClasspath()
+        def result = gradleRunner()
                 .withArguments('localizer')
                 .build()
 
         then:
         result.task(':localizer').outcome == TaskOutcome.SUCCESS
-        def generatedJavaFile = new File(project.root, 'build/generated-src/localizer/Messages.java')
+        def generatedJavaFile = new File(projectDir.root, 'build/generated-src/localizer/Messages.java')
         generatedJavaFile.exists()
         generatedJavaFile.text.contains('public static String key1()')
         generatedJavaFile.text.contains('public static String key2()')
     }
 
     def 'multi-module project should be able to run LocalizerTask'() {
         given:
-        project.newFile('build.gradle') << ''
-        project.newFile('settings.gradle') << 'include ":plugin"'
-        project.newFolder('plugin', 'src', 'main', 'resources')
-        project.newFile('plugin/build.gradle') << "plugins { id 'org.jenkins-ci.jpi' }"
-        project.newFile('plugin/src/main/resources/Messages.properties') << 'key3=value3\nkey4=value4'
+        projectDir.newFile('build.gradle') << ''
+        projectDir.newFile('settings.gradle') << 'include ":plugin"'
+        projectDir.newFolder('plugin', 'src', 'main', 'resources')
+        projectDir.newFile('plugin/build.gradle') << "plugins { id 'org.jenkins-ci.jpi' }"
+        projectDir.newFile('plugin/src/main/resources/Messages.properties') << 'key3=value3\nkey4=value4'
 
         when:
-        def result = GradleRunner.create()
-                .withProjectDir(project.root)
-                .withPluginClasspath()
+        def result = gradleRunner()
                 .withArguments(':plugin:localizer')
                 .build()
 
         then:
         result.task(':plugin:localizer').outcome == TaskOutcome.SUCCESS
-        def generatedJavaFile = new File(project.root, 'plugin/build/generated-src/localizer/Messages.java')
+        def generatedJavaFile = new File(projectDir.root, 'plugin/build/generated-src/localizer/Messages.java')
         generatedJavaFile.exists()
         generatedJavaFile.text.contains('public static String key3()')
         generatedJavaFile.text.contains('public static String key4()')

src/test/groovy/org/jenkinsci/gradle/plugins/jpi/JpiPomCustomizerIntegrationSpec.groovy

@@ -1,15 +1,10 @@
 package org.jenkinsci.gradle.plugins.jpi
 
-import org.gradle.testkit.runner.GradleRunner
-import org.junit.Rule
 import org.junit.rules.TemporaryFolder
 import org.xmlunit.builder.DiffBuilder
 import org.xmlunit.builder.Input
-import spock.lang.Specification
 
-class JpiPomCustomizerIntegrationSpec extends Specification {
-    @Rule
-    private final TemporaryFolder projectDir = new TemporaryFolder()
+class JpiPomCustomizerIntegrationSpec extends IntegrationSpec {
     private File settings
     private File build
 
@@ -33,7 +28,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('minimal-pom.xml', actualPomIn(projectDir))
@@ -72,7 +67,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('complex-pom.xml', actualPomIn(projectDir))
@@ -88,7 +83,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('bitbucket-pom.xml', actualPomIn(projectDir))
@@ -106,7 +101,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('minimal-pom.xml', actualPomIn(projectDir))
@@ -124,7 +119,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('minimal-pom.xml', actualPomIn(projectDir))
@@ -142,7 +137,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('plugin-dependencies-pom.xml', actualPomIn(projectDir))
@@ -160,7 +155,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('optional-plugin-dependencies-pom.xml', actualPomIn(projectDir))
@@ -178,7 +173,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('compile-dependencies-pom.xml', actualPomIn(projectDir))
@@ -198,7 +193,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('compile-dependencies-with-excludes-pom.xml', actualPomIn(projectDir))
@@ -213,7 +208,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('updated-findbugs-pom.xml', actualPomIn(projectDir))
@@ -228,7 +223,7 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
             """.stripIndent()
 
         when:
-        generatePomIn(projectDir)
+        generatePom()
 
         then:
         compareXml('updated-servlet-api-pom.xml', actualPomIn(projectDir))
@@ -253,10 +248,8 @@ class JpiPomCustomizerIntegrationSpec extends Specification {
         buffer.toString()
     }
 
-    static void generatePomIn(TemporaryFolder projectDir) {
-        GradleRunner.create()
-                .withPluginClasspath()
-                .withProjectDir(projectDir.root)
+    void generatePom() {
+        gradleRunner()
                 .withArguments('generatePomFileForMavenJpiPublication')
                 .build()
     }

src/test/groovy/org/jenkinsci/gradle/plugins/jpi/LicenseTaskSpec.groovy

@@ -1,26 +1,19 @@
 package org.jenkinsci.gradle.plugins.jpi
 
-import org.gradle.testkit.runner.GradleRunner
 import org.gradle.testkit.runner.TaskOutcome
-import org.junit.Rule
-import org.junit.rules.TemporaryFolder
 import org.xmlunit.builder.DiffBuilder
 import org.xmlunit.builder.Input
-import spock.lang.Specification
 
-class LicenseTaskSpec extends Specification {
-    @Rule
-    final TemporaryFolder temporaryFolder = new TemporaryFolder()
+class LicenseTaskSpec extends IntegrationSpec {
 
     def 'compute license information'() {
         given:
-        File projectFolder = temporaryFolder.newFolder('bar')
+        File projectFolder = projectDir.newFolder('bar')
         new File(projectFolder, 'build.gradle') << getClass().getResource('licenseInfo.gradle').text
 
         when:
-        def result = GradleRunner.create()
+        def result = gradleRunner()
                 .withProjectDir(projectFolder)
-                .withPluginClasspath()
                 .withArguments('generateLicenseInfo')
                 .build()
 

src/test/groovy/org/jenkinsci/gradle/plugins/jpi/UsesGradleTestKit.groovy

@@ -0,0 +1,4 @@
+package org.jenkinsci.gradle.plugins.jpi
+
+interface UsesGradleTestKit {
+}