@Optional
                @InputFile
                File inputFile

                @OutputFile
                File outputFile

                @TaskAction
                void doAction() {
                    if (inputFile != null) {
                        outputFile.text = inputFile.text
                    }
                }
            }

                @InputFile inputFile
                @OutputFile outputFile

                @TaskAction copy() {
                    outputFile.parentFile.mkdirs()
                    outputFile.text = inputFile.text
                }
            }
            task customTask(type: NonCacheableTask) {
                inputFile = file("input.txt")

                if (project.findProperty("inputFile")) {
                    input = file(project.property("inputFile"))
                }
            }
        """

        file("input").createDir()

        expect:
        succeeds("myTask")

        when:
        file("inputFile").createDir()
        file("inputFile/someContents.txt").text = "input"

        execute(unitOfWork)

        when:
        inputFile.write("some new content")

        then:
        outOfDate(unitOfWork, inputFilesChanged(file: [inputFile]))
    }

    def "out-of-date when any input file type changes"() {
        given:
        execute(unitOfWork)

        when:
        inputFile.delete()
        inputFile.createDir()

        then:

                abstract Provider<FileSystemLocation> getInput()

                void transform(TransformOutputs outputs) {
                    File inputFile = input.get().asFile
                    println "processing \${inputFile.name}"
                    def output = outputs.file(inputFile.name + "." + parameters.extension)
                    output.text = "ok"
                }
            }
        """

        when:

                @ValidationProblem inputFile

                @TaskAction void execute() {
                    println "Executed"
                }
            }

            task invalid(type: InvalidTask)
        """

        expectThatExecutionOptimizationDisabledWarningIsDisplayed(executer, dummyValidationProblem('InvalidTask', 'inputFile'), 'id', 'section')

        when:

        TaskWithNestedIterable                    | [new Bean()]                   | ["beans.\$0"]                                   | ["beans.\$0.inputFile"] | []
        TaskWithNestedBeanWithPrivateClass        | [null, null]                   | ["bean"]                                        | ["bean.inputFile"]      | []

        buildFile("""
            tasks.register("myTask") {
                doNotTrackState("For testing")
                def inputFile = file("input.txt")
                inputs.file(inputFile)
                    .withPropertyName("inputFile")
                def outputFile = project.layout.buildDirectory.file("output.txt")
                outputs.file(outputFile)

                    outputFile.text = "produced"
                }
            }

            task consumer {
                def inputFile = file("output.txt")
                inputs.files(inputFile)
                doLast {
                    println "Hello " + inputFile.text
                }
            }
        """

        when:
        runAndFail("producer", "consumer")
        then:

    static class MyTask extends DefaultTask {

        @Input
        String myProperty = "myValue"

        @InputFile
        @PathSensitive(PathSensitivity.NONE)
        File inputFile = new File("some-location")

        @InputFiles
        @PathSensitive(PathSensitivity.NONE)
        FileCollection inputFiles = TestFiles.fixed(new File("files"))

        @OutputFile
        File outputFile = new File("output")