@Test
  public void testFileSystemForDefaultOsXConfiguration() throws IOException {
    FileSystem fs = Jimfs.newFileSystem(Configuration.osX());

    assertThat(fs.getRootDirectories())
        .containsExactlyElementsIn(ImmutableList.of(fs.getPath("/")))
        .inOrder();
    assertThatPath(fs.getPath("").toRealPath()).isEqualTo(fs.getPath("/work"));
    assertThat(Iterables.getOnlyElement(fs.getFileStores()).getTotalSpace())
        .isEqualTo(4L * 1024 * 1024 * 1024);
    assertThat(fs.supportedFileAttributeViews()).containsExactly("basic");

    Files.createFile(fs.getPath("/foo"));

    try {
      Files.createFile(fs.getPath("/FOO"));
      fail();
    } catch (FileAlreadyExistsException expected) {
    }
  }
Tests for {@link Configuration}, {@link Configuration.Builder} and file systems created from
them.

@author Colin Decker
jimfs/src/test/java/com/google/common/jimfs/ConfigurationTest.java