assertThat(Files.toString(temp, UTF_8)).isEqualTo(ASCII);
  }

  public void testCopyIdenticalFiles() throws IOException {
    File temp1 = createTempFile();
    Files.write(ASCII, temp1, UTF_8);
    File temp2 = createTempFile();
    Files.write(ASCII, temp2, UTF_8);
    Files.copy(temp1, temp2);
    assertThat(Files.toString(temp2, UTF_8)).isEqualTo(ASCII);
  }

  public void testEqual() throws IOException {

// trailing white space, as defined by Unicode.
func TrimSpace(s []byte) []byte {
	// Fast path for ASCII: look for the first ASCII non-space byte.
	for lo, c := range s {
		if c >= utf8.RuneSelf {
			// If we run into a non-ASCII byte, fall back to the
			// slower unicode-aware method on the remaining bytes.
			return TrimFunc(s[lo:], unicode.IsSpace)
		}

    assertThat(xmlEscaper.escape("<tab>")).isEqualTo("&lt;tab&gt;");

    // Test all non-escaped ASCII characters.
    String s =
        "!@#$%^*()_+=-/?\\|]}[{,.;:"
            + "abcdefghijklmnopqrstuvwxyz"
            + "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
            + "1234567890";
    assertThat(xmlEscaper.escape(s)).isEqualTo(s);

    // Test ASCII control characters.
    for (char ch = 0; ch < 0x20; ch++) {

   * (<code>'&#92;u002D'</code>) is recognized as the minus sign.
   *
   * <p>Unlike {@link Integer#parseInt(String)}, this method returns {@code null} instead of
   * throwing an exception if parsing fails. Additionally, this method only accepts ASCII digits,
   * and returns {@code null} if non-ASCII digits are present in the string.
   *

      assertTrue(str, Ascii.isUpperCase(c));
    }
  }

  public void testTruncate() {
    assertThat(Ascii.truncate("foobar", 10, "...")).isEqualTo("foobar");
    assertThat(Ascii.truncate("foobar", 5, "...")).isEqualTo("fo...");
    assertThat(Ascii.truncate("foobar", 6, "...")).isEqualTo("foobar");
    assertThat(Ascii.truncate("foobar", 3, "...")).isEqualTo("...");

      assertTrue(str, Ascii.isUpperCase(c));
    }
  }

  public void testTruncate() {
    assertThat(Ascii.truncate("foobar", 10, "...")).isEqualTo("foobar");
    assertThat(Ascii.truncate("foobar", 5, "...")).isEqualTo("fo...");
    assertThat(Ascii.truncate("foobar", 6, "...")).isEqualTo("foobar");
    assertThat(Ascii.truncate("foobar", 3, "...")).isEqualTo("...");

    assertThat(xmlEscaper.escape("<tab>")).isEqualTo("&lt;tab&gt;");

    // Test all non-escaped ASCII characters.
    String s =
        "!@#$%^*()_+=-/?\\|]}[{,.;:"
            + "abcdefghijklmnopqrstuvwxyz"
            + "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
            + "1234567890";
    assertThat(xmlEscaper.escape(s)).isEqualTo(s);

    // Test ASCII control characters.
    for (char ch = 0; ch < 0x20; ch++) {

   * InetAddress}.
   *
   * <p>This method accepts non-ASCII digits, for example {@code "１９２.１６８.０.１"} (those are fullwidth
   * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you
   * want to accept ASCII digits only, you can use something like {@code
   * CharMatcher.ascii().matchesAllOf(ipString)}.
   *

/**
 * Tests for the default implementations of {@code CharSink} methods.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class CharSinkTest extends IoTestCase {

  private static final String STRING = ASCII + I18N;

  private TestCharSink sink;

  @Override
  public void setUp() {
    sink = new TestCharSink();
  }

  public void testOpenBufferedStream() throws IOException {

    boolean canDecode(char ch) {
      return ch <= Ascii.MAX && decodabet[ch] != -1;
    }

    int decode(char ch) throws DecodingException {
      if (ch > Ascii.MAX) {
        throw new DecodingException("Unrecognized character: 0x" + Integer.toHexString(ch));
      }
      int result = decodabet[ch];
      if (result == -1) {
        if (ch <= 0x20 || ch == Ascii.MAX) {