test/java/text/Bidi/BidiSurrogateTest.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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 * questions.
 */

/*
 * @test
 * @bug 4888843
 * @summary verify that surrogate pairs representing codepoints with R or AL directionality
 * and correctly recognized and reordered.
 */

import java.text.Bidi;

public class BidiSurrogateTest {
    private static final String RTLS = new String(Character.toChars(0x10800)); // surrogate code point with R directionality
    private static final String LTRS = new String(Character.toChars(0x107ff)); // surrogate code point with L directionality
    private static final String LRE = "\u202a";
    private static final String RLE = "\u202b";
    private static final String PDF = "\u202c";


    public static void main(String[] args) {
        new BidiSurrogateTest().test();
    }

    void test() {
        test0();
        test1();
    }

    void test0() {
        // test unpaired surrogates - should have L directionality
        testRequiresBidi("\ud800", false);           // unpaired lead surrogate
        testRequiresBidi("\udc00", false);           // unpaired trail surrogate
        testRequiresBidi("\udc00\ud800", false);     // out of order surrogates
        testRequiresBidi("a\udc00b\ud800c", false);  // out of order surrogates split
        testRequiresBidi(LTRS, false);               // supplementary with L
        testRequiresBidi(RTLS, true);                // supplementary with R
        testRequiresBidi("a" + RTLS + "b", true);    // R supplementary in LTR text
        testRequiresBidi(LTRS + RTLS, true);         // R supplementary in LTR supplementary text
        testRequiresBidi(LRE, false);                // LRE lone embedding
        testRequiresBidi(RLE, true);                 // RLE lone embedding
        testRequiresBidi(PDF, false);                // PDF lone pop embedding
    }

    void testRequiresBidi(String string, boolean requiresBidi) {
        char[] text = string.toCharArray();
        if (Bidi.requiresBidi(text, 0, text.length) != requiresBidi) {
            throw new RuntimeException("testRequiresBidi failed with '" + string + "', " + requiresBidi);
        }
    }

    void test1() {
        // test that strings with surrogate runs process surrogate directionality ok
        testBidi("This is a string with " + LTRS + " in it.", false);
        testBidi("This is a string with \ud800 in it.", false);
        testBidi("This is a string with \u0640 in it.", 22, 1);
        testBidi(RTLS, true);
        testBidi("This is a string with " + RTLS + RTLS + RTLS + " in it.", 22, 6);
    }

    void testBidi(String string, boolean directionIsRTL) {
        Bidi bidi = new Bidi(string, Bidi.DIRECTION_DEFAULT_LEFT_TO_RIGHT);
        if (bidi.isMixed()) {
            throw new RuntimeException("bidi is mixed");
        }
        if (bidi.isRightToLeft() != directionIsRTL) {
            throw new RuntimeException("bidi is not " + (directionIsRTL ? "rtl" : "ltr"));
        }
    }

    void testBidi(String string, int rtlstart, int rtllength) {
        Bidi bidi = new Bidi(string, Bidi.DIRECTION_DEFAULT_LEFT_TO_RIGHT);
        for (int i = 0; i < bidi.getRunCount(); ++i) {
            if ((bidi.getRunLevel(i) & 1) != 0) {
                if (bidi.getRunStart(i) != rtlstart ||
                    bidi.getRunLimit(i) != rtlstart + rtllength) {
                    throw new RuntimeException("first rtl run didn't match " + rtlstart + ", " + rtllength);
                }
                break;
            }
        }
    }
}