Introduce lazy tasks except for ktlint

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

@@ -8,14 +8,19 @@ import org.gradle.api.Project
 import org.gradle.api.Task
 import org.gradle.api.plugins.quality.CodeQualityExtension
 import org.gradle.api.tasks.SourceTask
+import org.gradle.api.tasks.VerificationTask
 
-abstract class CodeQualityConfigurator<T extends SourceTask, E extends CodeQualityExtension> implements Configurator {
+import static com.novoda.staticanalysis.internal.TasksCompat.configureEach
+import static com.novoda.staticanalysis.internal.TasksCompat.createTask
+
+abstract class CodeQualityConfigurator<T extends SourceTask & VerificationTask, E extends CodeQualityExtension> implements Configurator {
 
     protected final Project project
     protected final Violations violations
     protected final Task evaluateViolations
     protected final SourceFilter sourceFilter
     protected final VariantFilter variantFilter
+    protected boolean configured = false
 
     protected CodeQualityConfigurator(Project project, Violations violations, Task evaluateViolations) {
         this.project = project
@@ -38,29 +43,57 @@ abstract class CodeQualityConfigurator<T extends SourceTask, E extends CodeQuali
             }
             project.plugins.withId('com.android.application') {
                 configureAndroidWithVariants(variantFilter.filteredApplicationVariants)
-                configureToolTasks()
             }
             project.plugins.withId('com.android.library') {
                 configureAndroidWithVariants(variantFilter.filteredLibraryVariants)
-                configureToolTasks()
             }
             project.plugins.withId('java') {
                 configureJavaProject()
-                configureToolTasks()
             }
+            configureEach(project.tasks.withType(taskClass)) { task ->
+                configureToolTask(task)
+            }
+        }
+    }
+
+    protected void configureJavaProject() {
+        if (configured) return
+
+        project.sourceSets.all { sourceSet ->
+            def collectViolations = createCollectViolations(getToolTaskNameFor(sourceSet), violations)
+            evaluateViolations.dependsOn collectViolations
         }
+        configured = true
     }
 
-    def configureAndroidWithVariants(DomainObjectSet variants) {
-        variants.all { configureAndroidVariant(it) }
-        variantFilter.filteredTestVariants.all { configureAndroidVariant(it) }
-        variantFilter.filteredUnitTestVariants.all { configureAndroidVariant(it) }
+    protected void configureAndroidWithVariants(DomainObjectSet variants) {
+        if (configured) return
+
+        project.android.sourceSets.all { sourceSet ->
+            createToolTaskForAndroid(sourceSet)
+            createCollectViolations(getToolTaskNameFor(sourceSet), violations)
+        }
+        variants.all { configureVariant(it) }
+        variantFilter.filteredTestVariants.all { configureVariant(it) }
+        variantFilter.filteredUnitTestVariants.all { configureVariant(it) }
+        configured = true
     }
 
-    def configureToolTasks() {
-        project.tasks.withType(taskClass) { task ->
+    protected void configureVariant(variant) {
+        def collectViolations = createVariantMetaTask(variant)
+        evaluateViolations.dependsOn collectViolations
+    }
+
+    private def createVariantMetaTask(variant) {
+        createTask(project, "collect${getToolTaskNameFor(variant)}VariantViolations", Task) { task ->
             task.group = 'verification'
-            configureReportEvaluation(task, violations)
+            task.description = "Runs $toolName analysis on all sources for android ${variant.name} variant"
+            task.mustRunAfter javaCompile(variant)
+
+            variant.sourceSets.forEach { sourceSet ->
+                def toolTaskName = getToolTaskNameFor(sourceSet)
+                task.dependsOn "collect${toolTaskName.capitalize()}Violations"
+            }
         }
     }
 
@@ -78,17 +111,29 @@ abstract class CodeQualityConfigurator<T extends SourceTask, E extends CodeQuali
         }
     }
 
-    protected abstract void configureAndroidVariant(variant)
-
-    protected void configureJavaProject() {
-        project.tasks.withType(taskClass) { task ->
-            sourceFilter.applyTo(task)
-            task.exclude '**/*.kt'
+    protected static def javaCompile(variant) {
+        if (variant.hasProperty('javaCompileProvider')) {
+            variant.javaCompileProvider.get()
+        } else {
+            variant.javaCompile
         }
     }
 
+    protected final String getToolTaskNameFor(sourceSet) {
+        "$toolName${sourceSet.name.capitalize()}"
+    }
+
     protected abstract Class<T> getTaskClass()
 
-    protected abstract void configureReportEvaluation(T task, Violations violations)
+    protected abstract void createToolTaskForAndroid(sourceSet)
+
+    protected void configureToolTask(T task) {
+        sourceFilter.applyTo(task)
+        task.group = 'verification'
+        task.exclude '**/*.kt'
+        task.ignoreFailures = true
+        task.metaClass.getLogger = { QuietLogger.INSTANCE }
+    }
 
+    protected abstract def createCollectViolations(String taskName, Violations violations)
 }

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

@@ -0,0 +1,37 @@
+package com.novoda.staticanalysis.internal
+
+import org.gradle.api.Action
+import org.gradle.api.Project
+import org.gradle.api.Task
+import org.gradle.api.tasks.TaskCollection
+import org.gradle.util.GradleVersion
+
+class TasksCompat {
+
+    private static boolean IS_GRADLE_MIN_49 = GradleVersion.current() >= GradleVersion.version("4.9")
+
+    static <T extends Task> Object createTask(Project project, String name, Class<T> type, Action<? super T> configuration) {
+        if (IS_GRADLE_MIN_49) {
+            return project.tasks.register(name, type, configuration)
+        } else {
+            return project.tasks.create(name, type, configuration)
+        }
+    }
+
+    static <T extends Task> void configureEach(TaskCollection<T> tasks, Action<? super T> configuration) {
+        if (IS_GRADLE_MIN_49) {
+            tasks.configureEach(configuration)
+        } else {
+            tasks.all(configuration)
+        }
+    }
+
+    static <T extends Task> void configureNamed(Project project, String taskName, Action<? super T> configuration) {
+        if (IS_GRADLE_MIN_49) {
+            project.tasks.named(taskName).configure(configuration)
+        } else {
+            project.tasks.getByName(taskName).configure(configuration)
+        }
+    }
+
+}

plugin/src/main/groovy/com/novoda/staticanalysis/internal/checkstyle/CheckstyleConfigurator.groovy

@@ -2,14 +2,15 @@ package com.novoda.staticanalysis.internal.checkstyle
 
 import com.novoda.staticanalysis.Violations
 import com.novoda.staticanalysis.internal.CodeQualityConfigurator
-import com.novoda.staticanalysis.internal.QuietLogger
 import org.gradle.api.Action
 import org.gradle.api.NamedDomainObjectContainer
 import org.gradle.api.Project
 import org.gradle.api.Task
 import org.gradle.api.plugins.quality.Checkstyle
 import org.gradle.api.plugins.quality.CheckstyleExtension
 
+import static com.novoda.staticanalysis.internal.TasksCompat.createTask
+
 class CheckstyleConfigurator extends CodeQualityConfigurator<Checkstyle, CheckstyleExtension> {
 
     static CheckstyleConfigurator create(Project project,
@@ -48,42 +49,27 @@ class CheckstyleConfigurator extends CodeQualityConfigurator<Checkstyle, Checkst
     }
 
     @Override
-    protected void configureAndroidVariant(variant) {
-        project.with {
-            variant.sourceSets.each { sourceSet ->
-                def taskName = "checkstyle${sourceSet.name.capitalize()}"
-                Checkstyle task = tasks.findByName(taskName)
-                if (task == null) {
-                    task = tasks.create(taskName, Checkstyle)
-                    task.with {
-                        description = "Run Checkstyle analysis for ${sourceSet.name} classes"
-                        source = sourceSet.java.srcDirs
-                        classpath = files("$buildDir/intermediates/classes/")
-                        exclude '**/*.kt'
-                    }
-                }
-                sourceFilter.applyTo(task)
-                task.mustRunAfter variant.javaCompile
-            }
+    protected void createToolTaskForAndroid(sourceSet) {
+        createTask(project, getToolTaskNameFor(sourceSet), Checkstyle) { task ->
+            task.description = "Run Checkstyle analysis for ${sourceSet.name} classes"
+            task.source = sourceSet.java.srcDirs
+            task.classpath = project.files("${project.buildDir}/intermediates/classes/")
         }
     }
 
     @Override
-    protected void configureReportEvaluation(Checkstyle checkstyle, Violations violations) {
-        checkstyle.showViolations = false
-        checkstyle.ignoreFailures = true
-        checkstyle.metaClass.getLogger = { QuietLogger.INSTANCE }
-
-        def collectViolations = createCollectViolationsTask(checkstyle, violations)
-
-        evaluateViolations.dependsOn collectViolations
-        collectViolations.dependsOn checkstyle
+    protected void configureToolTask(Checkstyle task) {
+        super.configureToolTask(task)
+        task.showViolations = false
     }
 
-    private CollectCheckstyleViolationsTask createCollectViolationsTask(Checkstyle checkstyle, Violations violations) {
-        def task = project.tasks.maybeCreate("collect${checkstyle.name.capitalize()}Violations", CollectCheckstyleViolationsTask)
-        task.xmlReportFile = checkstyle.reports.xml.destination
-        task.violations = violations
-        task
+    @Override
+    protected def createCollectViolations(String taskName, Violations violations) {
+        createTask(project, "collect${taskName.capitalize()}Violations", CollectCheckstyleViolationsTask) { task ->
+            def checkstyle = project.tasks[taskName] as Checkstyle
+            task.xmlReportFile = checkstyle.reports.xml.destination
+            task.violations = violations
+            task.dependsOn(checkstyle)
+        }
     }
 }

plugin/src/main/groovy/com/novoda/staticanalysis/internal/detekt/DetektConfigurator.groovy

@@ -9,6 +9,8 @@ import org.gradle.api.NamedDomainObjectContainer
 import org.gradle.api.Project
 import org.gradle.api.Task
 
+import static com.novoda.staticanalysis.internal.TasksCompat.createTask
+
 class DetektConfigurator implements Configurator {
 
     private static final String DETEKT_PLUGIN = 'io.gitlab.arturbosch.detekt'
@@ -66,7 +68,7 @@ class DetektConfigurator implements Configurator {
         }
     }
 
-    private CollectCheckstyleViolationsTask configureToolTask(detekt) {
+    private def configureToolTask(detekt) {
         def detektTask = project.tasks.findByName('detekt')
         if (detektTask?.hasProperty('reports')) {
             def reports = detektTask.reports
@@ -105,13 +107,12 @@ class DetektConfigurator implements Configurator {
         }
     }
 
-    private CollectCheckstyleViolationsTask createCollectViolationsTask(Violations violations, detektTask, File xmlReportFile, File htmlReportFile) {
-        project.tasks.create('collectDetektViolations', CollectCheckstyleViolationsTask) { task ->
+    private def createCollectViolationsTask(Violations violations, detektTask, File xmlReportFile, File htmlReportFile) {
+        createTask(project, 'collectDetektViolations', CollectCheckstyleViolationsTask) { task ->
             task.xmlReportFile = xmlReportFile
             task.htmlReportFile = htmlReportFile
             task.violations = violations
-
-            task.dependsOn(detektTask)
+            task.dependsOn detektTask
         }
     }