Ktlint integration

plugin/src/main/groovy/com/novoda/staticanalysis/StaticAnalysisPlugin.groovy

@@ -4,6 +4,7 @@ import com.novoda.staticanalysis.internal.CodeQualityConfigurator
 import com.novoda.staticanalysis.internal.checkstyle.CheckstyleConfigurator
 import com.novoda.staticanalysis.internal.detekt.DetektConfigurator
 import com.novoda.staticanalysis.internal.findbugs.FindbugsConfigurator
+import com.novoda.staticanalysis.internal.ktlint.KtlintConfigurator
 import com.novoda.staticanalysis.internal.lint.LintConfigurator
 import com.novoda.staticanalysis.internal.pmd.PmdConfigurator
 import org.gradle.api.NamedDomainObjectContainer
@@ -40,6 +41,7 @@ class StaticAnalysisPlugin implements Plugin<Project> {
                 PmdConfigurator.create(project, violationsContainer, evaluateViolations),
                 FindbugsConfigurator.create(project, violationsContainer, evaluateViolations),
                 DetektConfigurator.create(project, violationsContainer, evaluateViolations),
+                KtlintConfigurator.create(project, violationsContainer, evaluateViolations),
                 LintConfigurator.create(project, violationsContainer, evaluateViolations)
         ]
     }

plugin/src/main/groovy/com/novoda/staticanalysis/internal/CollectViolationsTask.groovy

@@ -2,10 +2,12 @@ package com.novoda.staticanalysis.internal
 
 import com.novoda.staticanalysis.Violations
 import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.InputFile
 import org.gradle.api.tasks.TaskAction
 
 abstract class CollectViolationsTask extends DefaultTask {
 
+    @InputFile
     private File xmlReportFile
     private File htmlReportFile
     private Violations violations

plugin/src/main/groovy/com/novoda/staticanalysis/internal/ktlint/KtlintConfigurator.groovy

@@ -0,0 +1,97 @@
+package com.novoda.staticanalysis.internal.ktlint
+
+import com.novoda.staticanalysis.StaticAnalysisExtension
+import com.novoda.staticanalysis.Violations
+import com.novoda.staticanalysis.internal.Configurator
+import com.novoda.staticanalysis.internal.VariantFilter
+import com.novoda.staticanalysis.internal.checkstyle.CollectCheckstyleViolationsTask
+import org.gradle.api.GradleException
+import org.gradle.api.NamedDomainObjectContainer
+import org.gradle.api.Project
+import org.gradle.api.Task
+
+class KtlintConfigurator implements Configurator {
+
+    private static final String KTLINT_PLUGIN = 'org.jlleitschuh.gradle.ktlint'
+    private static final String KTLINT_NOT_APPLIED = 'The Ktlint plugin is configured but not applied. Please apply the plugin in your build script.\nFor more information see https://github.com/jeremymailen/kotlinter-gradle'
+
+    private final Project project
+    private final Violations violations
+    private final Task evaluateViolations
+    private final VariantFilter variantFilter
+
+    static KtlintConfigurator create(Project project,
+                                     NamedDomainObjectContainer<Violations> violationsContainer,
+                                     Task evaluateViolations) {
+        Violations violations = violationsContainer.maybeCreate('ktlint')
+        return new KtlintConfigurator(project, violations, evaluateViolations)
+    }
+
+    KtlintConfigurator(Project project, Violations violations, Task evaluateViolations) {
+        this.project = project
+        this.violations = violations
+        this.evaluateViolations = evaluateViolations
+        this.variantFilter = new VariantFilter(project)
+    }
+
+    @Override
+    void execute() {
+        project.extensions.findByType(StaticAnalysisExtension).ext.ktlint = { Closure config ->
+            if (!project.plugins.hasPlugin(KTLINT_PLUGIN)) {
+                throw new GradleException(KTLINT_NOT_APPLIED)
+            }
+
+            def ktlint = project.ktlint
+            ktlint.ignoreFailures = true
+            ktlint.reporters = ['CHECKSTYLE', 'PLAIN']
+            ktlint.ext.includeVariants = { Closure<Boolean> filter ->
+                variantFilter.includeVariantsFilter = filter
+            }
+            config.delegate = ktlint
+            config()
+
+            project.afterEvaluate {
+
+                project.plugins.withId("kotlin") {
+                    configureKotlinProject()
+                }
+                project.plugins.withId("kotlin2js") {
+                    configureKotlinProject()
+                }
+                project.plugins.withId("kotlin-platform-common") {
+                    configureKotlinProject()
+                }
+                project.plugins.withId('com.android.application') {
+                    configureAndroidWithVariants(variantFilter.filteredApplicationVariants)
+                }
+                project.plugins.withId('com.android.library') {
+                    configureAndroidWithVariants(variantFilter.filteredLibraryVariants)
+                }
+            }
+        }
+    }
+
+    private void configureKotlinProject() {
+        project.sourceSets.each { configureKtlint(it) }
+    }
+
+    private void configureAndroidWithVariants(def mainVariants) {
+        mainVariants.all { configureKtlint(it) }
+        variantFilter.filteredTestVariants.all { configureKtlint(it) }
+        variantFilter.filteredUnitTestVariants.all { configureKtlint(it) }
+    }
+
+    private void configureKtlint(def sourceSet) {
+        def collectViolations = createCollectViolationsTask(violations, sourceSet.name)
+        evaluateViolations.dependsOn collectViolations
+    }
+
+    private def createCollectViolationsTask(Violations violations, def sourceSetName) {
+        project.tasks.create("collectKtlint${sourceSetName.capitalize()}Violations", CollectCheckstyleViolationsTask) { task ->
+            task.xmlReportFile = new File(project.buildDir, "reports/ktlint/ktlint-${sourceSetName}.xml")
+            task.htmlReportFile = new File(project.buildDir, "reports/ktlint/ktlint-${sourceSetName}.txt")
+            task.violations = violations
+            task.dependsOn project.tasks["ktlint${sourceSetName.capitalize()}Check"]
+        }
+    }
+}

plugin/src/test/fixtures/sources/ktlint/no-error/ValidClass.kt

@@ -0,0 +1 @@
+data class ValidClass(val prop1: String, val prop2: Int)

plugin/src/test/fixtures/sources/ktlint/with-error/KtLintViolator.kt

@@ -0,0 +1,7 @@
+class KtLintViolator {
+
+    override fun equals(other: Any?): Boolean {
+        // this is not allowed
+        return true;
+    }
+}

plugin/src/test/groovy/com/novoda/staticanalysis/internal/ktlint/KtlintIntegrationTest.groovy

@@ -0,0 +1,98 @@
+package com.novoda.staticanalysis.internal.ktlint
+
+import com.novoda.test.Fixtures
+import com.novoda.test.TestProject
+import com.novoda.test.TestProjectRule
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.Parameterized
+
+import static com.novoda.test.LogsSubject.assertThat
+
+@RunWith(Parameterized.class)
+class KtlintIntegrationTest {
+
+    private static final String KTLINT_NOT_APPLIED = 'The Ktlint plugin is configured but not applied. Please apply the plugin in your build script.'
+    public static final String DEFAULT_CONFIG = '''
+                    ktlint {
+                        includeVariants { it.name == "debug" }
+                    }
+                    '''
+    public static final String EMPTY_CONFIG = 'ktlint {}'
+
+    @Parameterized.Parameters(name = '{0}')
+    static def rules() {
+        return [
+                [TestProjectRule.forKotlinProject(), 'main'].toArray(),
+                [TestProjectRule.forAndroidKotlinProject(), 'debug'].toArray()
+        ]
+    }
+
+    @Rule
+    public final TestProjectRule projectRule
+    private final String sourceSetName;
+
+    KtlintIntegrationTest(TestProjectRule projectRule, String sourceSetName) {
+        this.projectRule = projectRule
+        this.sourceSetName = sourceSetName
+    }
+
+    @Test
+    void shouldNotFailWhenKtlintIsNotConfigured() {
+        def result = createProjectWith(Fixtures.Ktlint.SOURCES_WITH_ERROR)
+                .build('evaluateViolations')
+
+        assertThat(result.logs).doesNotContainKtlintViolations()
+    }
+
+    @Test
+    void shouldFailBuildOnConfigurationWhenKtlintConfiguredButNotApplied() {
+        def result = projectRule.newProject()
+                .withToolsConfig(EMPTY_CONFIG)
+                .buildAndFail('evaluateViolations')
+
+        assertThat(result.logs).contains(KTLINT_NOT_APPLIED)
+    }
+
+    @Test
+    void shouldFailBuildWhenKtlintErrorsOverTheThreshold() {
+        def result = createProjectWith(Fixtures.Ktlint.SOURCES_WITH_ERROR)
+                .withToolsConfig(DEFAULT_CONFIG)
+                .buildAndFail('evaluateViolations')
+
+        assertThat(result.logs).containsLimitExceeded(1, 0)
+        assertThat(result.logs).containsKtlintViolations(1,
+                result.buildFileUrl("reports/ktlint/ktlint-${sourceSetName}.txt"))
+    }
+
+    @Test
+    void shouldNotFailWhenErrorsAreWithinThreshold() {
+        def result = createProjectWith(Fixtures.Ktlint.SOURCES_WITH_ERROR, 1)
+                .withToolsConfig(DEFAULT_CONFIG)
+                .build('evaluateViolations')
+
+        assertThat(result.logs).containsKtlintViolations(1,
+                result.buildFileUrl("reports/ktlint/ktlint-${sourceSetName}.txt"))
+    }
+
+    @Test
+    void shouldNotFailBuildWhenNoErrorsEncounteredAndNoThresholdTrespassed() {
+        def result = createProjectWith(Fixtures.Ktlint.SOURCES_NO_ERROR, 0)
+                .withToolsConfig(EMPTY_CONFIG)
+                .build('evaluateViolations')
+
+        assertThat(result.logs).doesNotContainLimitExceeded()
+        assertThat(result.logs).doesNotContainKtlintViolations()
+    }
+
+    private TestProject createProjectWith(File sources, int maxErrors = 0) {
+        projectRule.newProject()
+                .withPlugin('org.jlleitschuh.gradle.ktlint', '4.1.0')
+                .withSourceSet('main', sources)
+                .withPenalty("""{
+                    maxWarnings = 0
+                    maxErrors = ${maxErrors}
+                }""")
+    }
+}

plugin/src/test/groovy/com/novoda/test/Fixtures.groovy

@@ -50,6 +50,11 @@ public final class Fixtures {
         public static final File RULES = new File(RULES_DIR, 'detekt/detekt.yml')
     }
 
+    final static class Ktlint {
+        static final File SOURCES_WITH_ERROR = new File(SOURCES_DIR, 'ktlint/with-error')
+        static final File SOURCES_NO_ERROR = new File(SOURCES_DIR, 'ktlint/no-error')
+    }
+
     final static class Lint {
         public static final File SOURCES_WITH_WARNINGS = new File(SOURCES_DIR, 'lint/warnings')
         public static final File SOURCES_WITH_ERRORS = new File(SOURCES_DIR, 'lint/errors')

plugin/src/test/groovy/com/novoda/test/LogsSubject.groovy

@@ -18,6 +18,7 @@ class LogsSubject extends Subject<LogsSubject, Logs> {
     private static final String PMD_VIOLATIONS_FOUND = 'PMD violations found'
     private static final String FINDBUGS_VIOLATIONS_FOUND = 'Findbugs violations found'
     private static final String DETEKT_VIOLATIONS_FOUND = 'Detekt violations found'
+    private static final String KTLINT_VIOLATIONS_FOUND = 'ktlint violations found'
     private static final String LINT_VIOLATIONS_FOUND = 'Lint violations found'
 
     private static final SubjectFactory<LogsSubject, Logs> FACTORY = new SubjectFactory<LogsSubject, Logs>() {
@@ -71,6 +72,10 @@ class LogsSubject extends Subject<LogsSubject, Logs> {
         outputSubject.doesNotContain(DETEKT_VIOLATIONS_FOUND)
     }
 
+    public void doesNotContainKtlintViolations() {
+        outputSubject.doesNotContain(KTLINT_VIOLATIONS_FOUND)
+    }
+
     public void doesNotContainLintViolations() {
         outputSubject.doesNotContain(LINT_VIOLATIONS_FOUND)
     }
@@ -91,6 +96,10 @@ class LogsSubject extends Subject<LogsSubject, Logs> {
         containsToolViolations(DETEKT_VIOLATIONS_FOUND, errors, warnings, reportUrls)
     }
 
+    public void containsKtlintViolations(int errors, String... reportUrls) {
+        containsToolViolations(KTLINT_VIOLATIONS_FOUND, errors, 0, reportUrls)
+    }
+
     public void containsLintViolations(int errors, int warnings, String... reportUrls) {
         containsToolViolations(LINT_VIOLATIONS_FOUND, errors, warnings, reportUrls)
     }

plugin/src/test/groovy/com/novoda/test/TestAndroidKotlinProject.groovy

@@ -14,7 +14,8 @@ buildscript {
     }
 }
 plugins {
-    ${formatPlugins(project)}
+    ${formatPlugins(project)}   
+    id 'com.novoda.static-analysis'
 }
 repositories {
     google()
@@ -58,7 +59,7 @@ ${formatExtension(project)}
                 .collect { Map.Entry<String, List<String>> entry ->
             """$entry.key {
             manifest.srcFile '${Fixtures.ANDROID_MANIFEST}'
-            kotlin {
+            java {
                 ${entry.value.collect { "srcDir '$it'" }.join('\n\t\t\t\t')}
             }
         }"""

plugin/src/test/groovy/com/novoda/test/TestAndroidProject.groovy

@@ -14,6 +14,7 @@ buildscript {
 }
 plugins {
     ${formatPlugins(project)}
+    id 'com.novoda.static-analysis'
 }
 repositories { 
     google()

plugin/src/test/groovy/com/novoda/test/TestJavaProject.groovy

@@ -5,7 +5,8 @@ final class TestJavaProject extends TestProject<TestJavaProject> {
     private static final Closure<String> TEMPLATE = { TestProject project ->
         """
 plugins {
-    ${formatPlugins(project)}
+    ${formatPlugins(project)} 
+    id 'com.novoda.static-analysis'
 }
 repositories {
     jcenter()

plugin/src/test/groovy/com/novoda/test/TestKotlinProject.groovy

@@ -15,9 +15,15 @@ buildscript {
 
 plugins {
     ${formatPlugins(project)}
+    id 'com.novoda.static-analysis'
 }
 
 apply plugin: 'kotlin'
+
+repositories { 
+    jcenter()
+}
+
 sourceSets {
     ${formatSourceSets(project)}
 }

plugin/src/test/groovy/com/novoda/test/TestProject.groovy

@@ -34,7 +34,6 @@ ${project.additionalConfiguration}
                 .withPluginClasspath()
                 .forwardStdOutput(new OutputStreamWriter(System.out))
                 .forwardStdError(new OutputStreamWriter(System.out))
-        withPlugin('com.novoda.static-analysis')
     }
 
     private static File createProjectDir(String path) {
@@ -126,7 +125,7 @@ ${project.additionalConfiguration}
     }
 
     protected static String formatPlugins(TestProject project) {
-        "${project.plugins.join('\n')}"
+        project.plugins.join('\n')
     }
 
     public static class Result {