Task configuration avoidance

Register the taskTree task lazily.
This might help slightly with preformance when
the taskTree task is NOT run.

resolves #35

src/main/groovy/com/dorongold/gradle/tasktree/TaskTreePlugin.groovy

@@ -12,9 +12,11 @@ import org.gradle.util.GradleVersion
  */
 class TaskTreePlugin implements Plugin<Project> {
 
+ private static boolean IS_GRADLE_MIN_49 = GradleVersion.current().compareTo(GradleVersion.version('4.9-rc-1')) >= 0
+ private static boolean IS_GRADLE_MIN_50 = GradleVersion.current().compareTo(GradleVersion.version('5.0-milestone-1')) >= 0
+
  public static final String TASK_TREE_TASK_NAME = 'taskTree'
  public static String GRADLE_MINIMUM_SUPPORTED_VERSION = '2.3'
- public static String GRADLE_VERSION_5 = '5.0-milestone-1'
  public static String UNSUPPORTED_GRADLE_VERSION_MESSAGE =
  "The taskTree task (defined by the task-tree plugin) cannot be run on a gradle version older than ${GRADLE_MINIMUM_SUPPORTED_VERSION}"
 
@@ -25,10 +27,10 @@ class TaskTreePlugin implements Plugin<Project> {
  // Skip if this sub-project already has our task. This can happen for example if the plugin is applied on allProjects.
  return
  }
- if (GradleVersion.current() < GradleVersion.version(GRADLE_VERSION_5)) {
- p.task(TASK_TREE_TASK_NAME, type: TaskTreeTaskOld)
+ if (IS_GRADLE_MIN_50) {
+ createTask(p, TaskTreeTaskNew, TASK_TREE_TASK_NAME)
  } else {
- p.task(TASK_TREE_TASK_NAME, type: TaskTreeTaskNew)
+ createTask(p, TaskTreeTaskOld, TASK_TREE_TASK_NAME)
  }
  p.gradle.taskGraph.whenReady {
  if (project.gradle.taskGraph.allTasks.any { Task task -> task.class in TaskTreeTask }) {
@@ -49,4 +51,13 @@ class TaskTreePlugin implements Plugin<Project> {
  }
  }
 
+ private static def createTask(Project project, Class type, String name) {
+ if (IS_GRADLE_MIN_49) {
+ // Lazy - avoids task configuration if not run
+ return project.tasks.register(name, type)
+ } else {
+ return project.tasks.create(name, type)
+ }
+ }
+
 }