jdk-24/test/jdk/java/lang/StringBuilder/StringBufferRepeat.java

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import org.testng.annotations.Test;

import static org.testng.Assert.assertEquals;

import java.util.Arrays;

/**
 * @test
 * @bug 8302323 8322512
 * @summary Test StringBuffer.repeat sanity tests
 * @run testng/othervm -XX:-CompactStrings StringBufferRepeat
 * @run testng/othervm -XX:+CompactStrings StringBufferRepeat
 */
@Test
public class StringBufferRepeat {
    private static class MyChars implements CharSequence {
        private static final char[] DATA = new char[] { 'a', 'b', 'c' };

        @Override
        public int length() {
            return DATA.length;
        }

        @Override
        public char charAt(int index) {
            return DATA[index];
        }

        @Override
        public CharSequence subSequence(int start, int end) {
            return new String(Arrays.copyOfRange(DATA, start, end));
        }
    }

    private static final MyChars MYCHARS = new MyChars();

    public void sanity() {
        StringBuffer sb = new StringBuffer();
        // prime the StringBuffer
        sb.append("repeat");

        // single character Latin1
        sb.repeat('1', 0);
        sb.repeat('2', 1);
        sb.repeat('3', 5);

        // single string Latin1 (optimized)
        sb.repeat("1", 0);
        sb.repeat("2", 1);
        sb.repeat("3", 5);

        // multi string Latin1
        sb.repeat("-1", 0);
        sb.repeat("-2", 1);
        sb.repeat("-3", 5);

        // single character UTF16
        sb.repeat('\u2460', 0);
        sb.repeat('\u2461', 1);
        sb.repeat('\u2462', 5);

        // single string UTF16 (optimized)
        sb.repeat("\u2460", 0);
        sb.repeat("\u2461", 1);
        sb.repeat("\u2462", 5);

        // multi string UTF16

        sb.repeat("-\u2460", 0);
        sb.repeat("-\u2461", 1);
        sb.repeat("-\u2462", 5);

        // CharSequence
        sb.repeat(MYCHARS, 3);

        // null
        sb.repeat((String)null, 0);
        sb.repeat((String)null, 1);
        sb.repeat((String)null, 5);
        sb.repeat((CharSequence)null, 0);
        sb.repeat((CharSequence)null, 1);
        sb.repeat((CharSequence)null, 5);


        String expected = "repeat233333233333-2-3-3-3-3-3\u2461\u2462\u2462\u2462\u2462\u2462\u2461\u2462\u2462\u2462\u2462\u2462-\u2461-\u2462-\u2462-\u2462-\u2462-\u2462abcabcabc" +
                          "nullnullnullnullnullnullnullnullnullnullnullnull";
        assertEquals(expected, sb.toString());

        // Codepoints

        sb.setLength(0);

        sb.repeat(0, 0);
        sb.repeat(0, 1);
        sb.repeat(0, 5);
        sb.repeat((int)' ', 0);
        sb.repeat((int)' ', 1);
        sb.repeat((int)' ', 5);
        sb.repeat(0x2460, 0);
        sb.repeat(0x2461, 1);
        sb.repeat(0x2462, 5);
        sb.repeat(0x10FFFF, 0);
        sb.repeat(0x10FFFF, 1);
        sb.repeat(0x10FFFF, 5);

        expected = "\u0000\u0000\u0000\u0000\u0000\u0000\u0020\u0020\u0020\u0020\u0020\u0020\u2461\u2462\u2462\u2462\u2462\u2462\udbff\udfff\udbff\udfff\udbff\udfff\udbff\udfff\udbff\udfff\udbff\udfff";
        assertEquals(expected, sb.toString());

        // toStringCache

        sb.setLength(0);
        sb.toString();
        sb.repeat('*', 5);
        expected = "*****";
        assertEquals(sb.toString(), expected);
        sb.setLength(0);
        sb.toString();
        sb.repeat("*", 5);
        assertEquals(sb.toString(), expected);


    }

    public void exceptions() {
        StringBuffer sb = new StringBuffer();

        try {
            sb.repeat(' ', Integer.MAX_VALUE);
            throw new RuntimeException("No OutOfMemoryError thrown");
        } catch (OutOfMemoryError | IndexOutOfBoundsException ex) {
            // Okay
        }

        try {
            sb.repeat("    ", Integer.MAX_VALUE);
            throw new RuntimeException("No OutOfMemoryError thrown");
        } catch (OutOfMemoryError | IndexOutOfBoundsException ex) {
            // Okay
        }

        try {
            sb.repeat(MYCHARS, Integer.MAX_VALUE);
            throw new RuntimeException("No OutOfMemoryError thrown");
        } catch (OutOfMemoryError | IndexOutOfBoundsException ex) {
            // Okay
        }

        try {
            sb.repeat(' ', -1);
            throw new RuntimeException("No IllegalArgumentException thrown");
        } catch (IllegalArgumentException ex) {
            // Okay
        }

        try {
            sb.repeat("abc", -1);
            throw new RuntimeException("No IllegalArgumentException thrown");
        } catch (IllegalArgumentException ex) {
            // Okay
        }

        try {
            sb.repeat(MYCHARS, -1);
            throw new RuntimeException("No IllegalArgumentException thrown");
        } catch (IllegalArgumentException ex) {
            // Okay
        }

        try {
            sb.repeat(0x10FFFF + 1, -1);
            throw new RuntimeException("No IllegalArgumentException thrown");
        } catch (IllegalArgumentException ex) {
            // Okay
        }

        try {
            sb.repeat(-1, -1);
            throw new RuntimeException("No IllegalArgumentException thrown");
        } catch (IllegalArgumentException ex) {
            // Okay
        }

    }
}