* the License.
 */

/**
 * Interfaces, utilities, and simple implementations of escapers and encoders. The primary type is
 * {@link Escaper}.
 *
 * <p>Additional escapers implementations are found in the applicable packages: {@link
 * com.google.common.html.HtmlEscapers} in {@code com.google.common.html}, {@link

  private EscaperAsserts() {}

  /**
   * Asserts that an escaper behaves correctly with respect to null inputs.
   *
   * @param escaper the non-null escaper to test
   */
  public static void assertBasic(Escaper escaper) throws IOException {
    // Escapers operate on characters: no characters, no escaping.
    Assert.assertEquals("", escaper.escape(""));
    // Assert that escapers throw null pointer exceptions.
    try {

  private EscaperAsserts() {}

  /**
   * Asserts that an escaper behaves correctly with respect to null inputs.
   *
   * @param escaper the non-null escaper to test
   */
  public static void assertBasic(Escaper escaper) throws IOException {
    // Escapers operate on characters: no characters, no escaping.
    Assert.assertEquals("", escaper.escape(""));
    // Assert that escapers throw null pointer exceptions.
    try {

 *
 * <p>A {@code CharEscaper} instance is required to be stateless, and safe when used concurrently by
 * multiple threads.
 *
 * <p>Popular escapers are defined as constants in classes like {@link
 * com.google.common.html.HtmlEscapers} and {@link com.google.common.xml.XmlEscapers}. To create
 * your own escapers extend this class and implement the {@link #escape(char)} method.
 *
 * @author Sven Mawson
 * @since 15.0
 */
@GwtCompatible

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

/**
 * Escapers
 * for
 * HTML.
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>
 * library.
 */
@CheckReturnValue
@NullMarked
package com.google.common.html;

    // Test all escapes
    assertThat(xmlAttributeEscaper.escape("a\"b<c>d&e\"f'"))
        .isEqualTo("a&quot;b&lt;c&gt;d&amp;e&quot;f&apos;");
    // Test '\t', '\n' and '\r' are escaped.
    assertThat(xmlAttributeEscaper.escape("a\tb\nc\rd")).isEqualTo("a&#x9;b&#xA;c&#xD;d");
  }

  // Helper to assert common properties of xml escapers.
  static void assertBasicXmlEscaper(

    // Test all escapes
    assertThat(xmlAttributeEscaper.escape("a\"b<c>d&e\"f'"))
        .isEqualTo("a&quot;b&lt;c&gt;d&amp;e&quot;f&apos;");
    // Test '\t', '\n' and '\r' are escaped.
    assertThat(xmlAttributeEscaper.escape("a\tb\nc\rd")).isEqualTo("a&#x9;b&#xA;c&#xD;d");
  }

  // Helper to assert common properties of xml escapers.
  static void assertBasicXmlEscaper(

          }
        };
    EscaperAsserts.assertBasic(escaper);
    assertThat(escaper.escape("\tFish & Chips\n")).isEqualTo("<tab>Fish <and> Chips<newline>");

    // Verify that everything else is left unescaped.
    String safeChars = "\0\u0100\uD800\uDC00\uFFFF";
    assertThat(escaper.escape(safeChars)).isEqualTo(safeChars);

    // Ensure that Unicode escapers behave correctly wrt badly formed input.

 * correctly if you are considering implementing a new escaper you should favor using UnicodeEscaper
 * wherever possible.
 *
 * <p>A {@code UnicodeEscaper} instance is required to be stateless, and safe when used concurrently
 * by multiple threads.
 *
 * <p>Popular escapers are defined as constants in classes like {@link

   *
   * <p><b>Note:</b> This escaper only performs minimal escaping to make content structurally
   * compatible with HTML. Specifically, it does not perform entity replacement (symbolic or
   * numeric), so it does not replace non-ASCII code points with character references. This escaper
   * escapes only the following five ASCII characters: {@code '"&<>}.
   */
  public static Escaper htmlEscaper() {
    return HTML_ESCAPER;
  }