testDir = createTempDir();
    }

    return testDir;
  }

  /** Returns the file with the given name under the testdata directory. */
  protected final @Nullable File getTestFile(String name) throws IOException {
    File file = new File(getTestDir(), name);
    if (!file.exists()) {
      URL resourceUrl = IoTestCase.class.getResource("testdata/" + name);
      if (resourceUrl == null) {

            task.getLinksFile().convention(dslDocbook.flatMap(AssembleDslDocTask::getLinksFile));

            task.getDsldocUrl().convention("../dsl");
            task.getJavadocUrl().convention("../javadoc");
            task.getWebsiteUrl().convention("https://gradle.org");

            task.getDestFile().convention(dslReference.getStagingRoot().file("index.xml"));

    abstract RegularFileProperty getSourceFile();

    @PathSensitive(PathSensitivity.NONE)
    @InputFile
    abstract RegularFileProperty getLinksFile();

    @OutputFile
    abstract RegularFileProperty getDestFile();

    @Input
    abstract Property<String> getJavadocUrl();
    @Input
    abstract Property<String> getDsldocUrl();
    @Input
    abstract Property<String> getWebsiteUrl();
    @Input

    @PathSensitive(PathSensitivity.RELATIVE)
    @InputDirectory
    abstract DirectoryProperty getClassDocbookDirectory();

    @OutputFile
    abstract RegularFileProperty getDestFile();

    @OutputFile
    abstract RegularFileProperty getLinksFile();

    @TaskAction
    def transform() {
        XIncludeAwareXmlProvider provider = new XIncludeAwareXmlProvider()