final XCTestSourceElement test = new XCTestSourceElement(main.projectName) {
        @Override
        List<XCTestSourceFileElement> getTestSuites() {
            return [new XCTestSourceFileElement("CombinedTests") {
                final delegate = new SwiftAppTest(main, main.greeter, main.sum, main.multiply)

                @Override
                List<XCTestCaseElement> getTestCases() {

    final XCTestSourceElement test = new XCTestSourceElement(main.projectName) {
        @Override
        List<XCTestSourceFileElement> getTestSuites() {
            return [
                new XCTestSourceFileElement("CombinedTests") {
                    final delegate = new SwiftLibTest(main, main.greeter, main.sum, main.multiply)

                    @Override
                    List<XCTestCaseElement> getTestCases() {

        then:
        fails("test")
        failure.assertHasErrorOutput("value of type 'Greeter' has no member 'sayHello'")

        when:
        file("src/test/swift/CombinedTests.swift").replace("sayHello", "sayAloha")
        then:
        succeeds("test")
        result.assertTasksExecuted(tasks.debug.compile, tasks.test.allToInstall, ":xcTest", ":test")