javaProject.assertJarHasDescendants(javaProject.mainClassFile.name, javaProject.redundantClassFile.name)

        when:
        forceDelete(javaProject.redundantSourceFile)
        succeeds JAR_TASK_NAME

        then:
        javaProject.mainClassFile.assertIsFile()
        javaProject.redundantClassFile.assertDoesNotExist()
        javaProject.assertJarHasDescendants(javaProject.mainClassFile.name)

    }

    void assertBuildTasksSkipped(ExecutionResult result) {
        result.assertTaskSkipped(getCompileTaskPath())
        result.assertTaskSkipped(getJarTaskPath())
    }

    boolean assertJarHasDescendants(String... relativePaths) {
        new JarTestFixture(jarFile).hasDescendants(relativePaths)
    }