buildFile """
            class FileOutputTask extends DefaultTask {
                @InputFile
                final RegularFileProperty inputFile = project.objects.fileProperty()
                @OutputFile
                final RegularFileProperty outputFile = project.objects.fileProperty()

                @TaskAction
                void go() {
                    def file = outputFile.asFile.get()

        buildFile """
            class FileOutputTask extends DefaultTask {
                @InputFile
                final RegularFileProperty inputFile = project.objects.fileProperty()
                @OutputFile
                final RegularFileProperty outputFile = project.objects.fileProperty()

                @TaskAction
                void go() {
                    def file = outputFile.asFile.get()

            @UntrackedTask(because = "For testing")
            abstract class MyTask extends DefaultTask {
                @InputFile
                abstract RegularFileProperty getInputFile()
                @OutputFile
                abstract RegularFileProperty getOutputFile()
                @TaskAction
                void doStuff() {
                    outputFile.get().asFile.text = inputFile.get().asFile.text
                }

                }
            };
        }
    }

    public static class DefaultRegularFileVar extends AbstractFileVar<RegularFile, RegularFileProperty> implements RegularFileProperty, Managed {
        private final PathToFileResolver fileResolver;

        DefaultRegularFileVar(PropertyHost host, PathToFileResolver fileResolver) {
            super(host, RegularFile.class);

    @OutputFile
    @Optional
    public abstract RegularFileProperty getXmlOutputFile();

    @OutputFile
    @Optional
    public abstract RegularFileProperty getHtmlOutputFile();

    @OutputFile
    @Optional
    public abstract RegularFileProperty getTxtOutputFile();

    @Input
    public abstract Property<Boolean> getFailOnModification();

import org.gradle.api.file.ConfigurableFileCollection;
import org.gradle.api.file.EmptyFileVisitor;
import org.gradle.api.file.FileVisitDetails;
import org.gradle.api.file.RegularFileProperty;
import org.gradle.api.logging.Logger;
import org.gradle.api.logging.Logging;
import org.gradle.api.problems.ProblemSpec;
import org.gradle.api.problems.internal.GradleCoreProblemGroup;

                @InputFile
                final RegularFileProperty file

                NestedBeanWithInput(RegularFileProperty file) {
                    this.file = file
                }
            }

            class GeneratorTask extends DefaultTask {
                @OutputFile
                final RegularFileProperty outputFile = project.objects.fileProperty()

                @TaskAction

import org.gradle.api.artifacts.result.ResolvedArtifactResult;
import org.gradle.api.attributes.Usage;
import org.gradle.api.file.FileCollection;
import org.gradle.api.file.RegularFileProperty;
import org.gradle.api.internal.artifacts.configurations.ConfigurationRolesForMigration;
import org.gradle.api.internal.artifacts.configurations.RoleBasedConfigurationContainerInternal;

            abstract class WithNonIncrementalInput extends BaseIncrementalTask {

                @InputFile
                abstract RegularFileProperty getNonIncrementalInput()

                @Optional
                @OutputFile
                abstract RegularFileProperty getOutputFile()

                @Override
                void execute(InputChanges inputChanges) {

    private final Path lockFilesRoot;
    private final DomainObjectContext context;
    private final RegularFileProperty lockFile;
    private final FileResourceListener listener;

    public LockFileReaderWriter(FileResolver fileResolver, DomainObjectContext context, RegularFileProperty lockFile, FileResourceListener listener) {
        this.context = context;
        this.lockFile = lockFile;