import org.jspecify.annotations.Nullable;

/**
 * A {@code UnicodeEscaper} that escapes some set of Java characters using a UTF-8 based percent
 * encoding scheme. The set of safe characters (those which remain unescaped) can be specified on
 * construction.
 *
 * <p>This class is primarily used for creating URI escapers in {@link UrlEscapers} but can be used

          destIndex += charsSkipped;
        }
        if (escaped.length > 0) {
          System.arraycopy(escaped, 0, dest, destIndex, escaped.length);
          destIndex += escaped.length;
        }
        // If we dealt with an escaped character, reset the unescaped range.
        unescapedChunkStart = nextIndex;
      }
      index = nextEscapeIndex(s, nextIndex, end);
    }

    try {
      e.escape((String) null);
      fail("Escaping null string should throw exception");
    } catch (NullPointerException x) {
      // pass
    }

    // All URL escapers should leave 0-9, A-Z, a-z unescaped
    assertUnescaped(e, 'a');
    assertUnescaped(e, 'z');
    assertUnescaped(e, 'A');
    assertUnescaped(e, 'Z');
    assertUnescaped(e, '0');
    assertUnescaped(e, '9');

            // Create proper escaped pattern
            String escapedPattern = mimeType.replace("+", "\\+");

            // Verify escaped pattern matches
            assertTrue("Escaped pattern should match: " + mimeType, Pattern.compile(escapedPattern).matcher(mimeType).matches());

            // Verify unescaped pattern does NOT match

   * href="https://url.spec.whatwg.org/#url-code-points">many of these are accepted in modern
   * URLs</a>. (<a href="https://url.spec.whatwg.org/#path-state">If the escaper were to leave these
   * characters unescaped, they would be escaped by the consumer at parse time, anyway.</a>)
   * Additionally, the escaper escapes the slash character ("/"). While slashes are acceptable in

    UnicodeEscaper surrogateEscaper =
        new ArrayBasedUnicodeEscaper(NO_REPLACEMENTS, 0, 0x20000, null) {
          private final char[] escaped = new char[] {'X'};

          @Override
          protected char[] escapeUnsafe(int c) {
            return escaped;
          }
        };
    EscaperAsserts.assertBasic(surrogateEscaper);

    // A surrogate pair defining a code point within the safe range.

    try {
      e.escape((String) null);
      fail("Escaping null string should throw exception");
    } catch (NullPointerException x) {
      // pass
    }

    // All URL escapers should leave 0-9, A-Z, a-z unescaped
    assertUnescaped(e, 'a');
    assertUnescaped(e, 'z');
    assertUnescaped(e, 'A');
    assertUnescaped(e, 'Z');
    assertUnescaped(e, '0');
    assertUnescaped(e, '9');

    assertThat(spaceEscaper.escape("string with spaces")).isEqualTo("string with spaces");
  }

  /** Tests that if we add extra 'safe' characters they remain unescaped */
  public void testCustomEscaper() {
    UnicodeEscaper e = new PercentEscaper("+*/-", false);
    for (char c = 0; c < 128; c++) {
      if ((c >= '0' && c <= '9')
          || (c >= 'a' && c <= 'z')

    private Builder() {}

    /**
     * Sets the safe range of characters for the escaper. Characters in this range that have no
     * explicit replacement are considered 'safe' and remain unescaped in the output. If {@code
     * safeMax < safeMin} then the safe range is empty.
     *
     * @param safeMin the lowest 'safe' character
     * @param safeMax the highest 'safe' character

    assertThat(spaceEscaper.escape("string with spaces")).isEqualTo("string with spaces");
  }

  /** Tests that if we add extra 'safe' characters they remain unescaped */
  public void testCustomEscaper() {
    UnicodeEscaper e = new PercentEscaper("+*/-", false);
    for (char c = 0; c < 128; c++) {
      if ((c >= '0' && c <= '9')
          || (c >= 'a' && c <= 'z')