// Test simple escape of '&'.
    assertEquals("foo&bar", htmlEscaper().escape("foo&bar"));

    // If the string contains no escapes, it should return the arg.
    // Note: assert<b>Same</b> for this implementation.
    String s = "blah blah farhvergnugen";
    assertSame(s, htmlEscaper().escape(s));

    // Tests escapes at begin and end of string.
    assertEquals("&lt;p&gt;", htmlEscaper().escape("<p>"));

    // Test quotes are escaped.
    assertEquals(""test"", xmlAttributeEscaper.escape("\"test\""));
    assertEquals("'test'", xmlAttributeEscaper.escape("\'test'"));
    // Test all escapes
    assertEquals(
        "a&quot;b&lt;c&gt;d&amp;e&quot;f&apos;", xmlAttributeEscaper.escape("a\"b<c>d&e\"f'"));
    // Test '\t', '\n' and '\r' are escaped.

  }

  private static final Escaper XML_ESCAPER;
  private static final Escaper XML_CONTENT_ESCAPER;
  private static final Escaper XML_ATTRIBUTE_ESCAPER;

  static {
    Escapers.Builder builder = Escapers.builder();
    // The char values \uFFFE and \uFFFF are explicitly not allowed in XML
    // (Unicode code points above \uFFFF are represented via surrogate pairs
    // which means they are treated as pairs of safe characters).

    assertUnicodeEscaping(e, "%F4%8F%BF%BF", '\uDBFF', '\uDFFF');

    // simple string tests
    assertEquals("", e.escape(""));
    assertEquals("safestring", e.escape("safestring"));
    assertEquals("embedded%00null", e.escape("embedded\0null"));
    assertEquals("max%EF%BF%BFchar", e.escape("max\uffffchar"));
  }

  /** Tests the various ways that the space character can be handled */
  public void testPlusForSpace() {

    // Test simple escape of '&'.
    assertEquals("foo&bar", htmlEscaper().escape("foo&bar"));

    // If the string contains no escapes, it should return the arg.
    // Note: assert<b>Same</b> for this implementation.
    String s = "blah blah farhvergnugen";
    assertSame(s, htmlEscaper().escape(s));

    // Tests escapes at begin and end of string.
    assertEquals("&lt;p&gt;", htmlEscaper().escape("<p>"));

    // Test quotes are escaped.
    assertEquals(""test"", xmlAttributeEscaper.escape("\"test\""));
    assertEquals("'test'", xmlAttributeEscaper.escape("\'test'"));
    // Test all escapes
    assertEquals(
        "a&quot;b&lt;c&gt;d&amp;e&quot;f&apos;", xmlAttributeEscaper.escape("a\"b<c>d&e\"f'"));
    // Test '\t', '\n' and '\r' are escaped.

    assertUnicodeEscaping(e, "%F4%8F%BF%BF", '\uDBFF', '\uDFFF');

    assertEquals("", e.escape(""));
    assertEquals("safestring", e.escape("safestring"));
    assertEquals("embedded%00null", e.escape("embedded\0null"));
    assertEquals("max%EF%BF%BFchar", e.escape("max\uffffchar"));
  }

  // Helper to assert common expected behaviour of uri escapers.

 * the License.
 */

package com.google.common.html;

import com.google.common.annotations.GwtCompatible;
import com.google.common.escape.Escaper;
import com.google.common.escape.Escapers;

/**
 * {@code Escaper} instances suitable for strings to be included in HTML attribute values and
 * most elements' text contents. When possible, avoid manual escaping by using templating

  // Escapes nothing
  private static final UnicodeEscaper NOP_ESCAPER =
      new UnicodeEscaper() {
        @Override
        protected char @Nullable [] escape(int c) {
          return null;
        }
      };

  // Escapes everything except [a-zA-Z0-9]
  private static final UnicodeEscaper SIMPLE_ESCAPER =
      new UnicodeEscaper() {
        @Override

    Escaper escaper = Escapers.nullEscaper();
    EscaperAsserts.assertBasic(escaper);
    String s = "\0\n\t\\az09~\uD800\uDC00\uFFFF";
    assertEquals("null escaper should have no effect", s, escaper.escape(s));
  }

  public void testBuilderInitialStateNoReplacement() {
    // Unsafe characters aren't modified by default (unsafeReplacement == null).