Graphviz visualization of a Gradle project's task graph

task_graph.groovy

gradle.taskGraph.whenReady {
  println "rootProject: " + rootProject.name
  println "childProjects: " + rootProject.childProjects

  def dot = new File(rootProject.buildDir, 'project.dot')
  dot.delete()

  def command = "./gradlew " + gradle.startParameter.getTaskNames().join(" ")
  println "command: " + command

  dot << 'digraph {\n'
  dot << "  graph [label=\"${command}\\n \",labelloc=t,fontsize=30];\n"
  dot << '  node [style=filled, fillcolor="#bbbbbb"];\n'
  dot << '  rankdir=LR;\n\n'

  def taskmap = [:] // a map to ignore dups
  gradle.taskGraph.allTasks.each { task ->
    println "task: " + task.name + ", class: " + task.class.name

    task.taskDependencies.getDependencies(task).each { dep ->
      taskmap["  \"${dep.name}\" -> \"${task.name}\""] = ""
      dot << "  \"${dep.name}\" -> \"${task.name}\""
      dot << " [style=dotted]"
      dot << '\n'
    }
  }
  taskmap.each {
    dot << "$it.key"
    dot << " [style=dotted]"
    dot << '\n'
  }

  dot << '\n'
  dot << '}\n'

  def p = 'dot -Tpng -O project.dot'.execute([], rootProject.buildDir)
  p.waitFor()
  if (p.exitValue() != 0) {
    throw new RuntimeException(p.errorStream.text)
  }

  println("Task graph created at ${dot.absolutePath}.png")
}

gradle.taskGraph.afterTask { task ->
  def inputFiles = task.inputs.files
  def outputFiles = task.outputs.files
  println "  inputs: "
  for (int i=0; i<inputFiles.size(); i++) {
    println "  - " + inputFiles[i]
    if(i>10) {
      println "  - ${inputFiles.size() - 10} more files ..."
      break
    }
  }
  println "  outputs: "
  for (int i=0; i<outputFiles.size(); i++) {
    println "  - " + outputFiles[i]
    if(i>10) {
      println "  - ${outputFiles.size() - 10} more files ..."
      break
    }
  }
}