src/test/java/com/fasterxml/jackson/core/io/UTF8WriterTest.java

package com.fasterxml.jackson.core.io;

import java.io.*;

import org.junit.Assert;

import com.fasterxml.jackson.core.io.IOContext;
import com.fasterxml.jackson.core.io.UTF8Writer;
import com.fasterxml.jackson.core.util.BufferRecycler;

public class UTF8WriterTest
    extends com.fasterxml.jackson.core.BaseTest
{
    public void testSimple() throws Exception
    {
        BufferRecycler rec = new BufferRecycler();
        IOContext ctxt = new IOContext(rec, null, false);
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        UTF8Writer w = new UTF8Writer(ctxt, out);

        String str = "AB\u00A0\u1AE9\uFFFC";
        char[] ch = str.toCharArray();

        // Let's write 3 times, using different methods
        w.write(str);

        w.append(ch[0]);
        w.write(ch[1]);
        w.write(ch, 2, 3);
        w.flush();

        w.write(str, 0, str.length());
        w.close();

        // and thus should have 3 times contents
        byte[] data = out.toByteArray();
        assertEquals(3*10, data.length);
        String act = out.toString("UTF-8");
        assertEquals(15, act.length());

        assertEquals(3 * str.length(), act.length());
        assertEquals(str+str+str, act);
    }

    public void testSimpleAscii() throws Exception
    {
        BufferRecycler rec = new BufferRecycler();
        IOContext ctxt = new IOContext(rec, null, false);
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        UTF8Writer w = new UTF8Writer(ctxt, out);

        String str = "abcdefghijklmnopqrst\u00A0";
        char[] ch = str.toCharArray();

        w.write(ch, 0, ch.length);
        w.flush(); // trigger different code path for close
        w.close();

        byte[] data = out.toByteArray();
        // one 2-byte encoded char
        assertEquals(ch.length+1, data.length);
        String act = out.toString("UTF-8");
        assertEquals(str, act);
    }
    
    public void testFlushAfterClose() throws Exception
    {
        BufferRecycler rec = new BufferRecycler();
        IOContext ctxt = new IOContext(rec, null, false);
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        UTF8Writer w = new UTF8Writer(ctxt, out);
        
        w.write('X');
        char[] ch = { 'Y' };
        w.write(ch);
        
        w.close();
        assertEquals(2, out.size());

        // and this ought to be fine...
        w.flush();
        // as well as some more...
        w.close();
        w.flush();
    }

    public void testSurrogatesOk() throws Exception
    {
        BufferRecycler rec = new BufferRecycler();
        IOContext ctxt = new IOContext(rec, null, false);
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        UTF8Writer w = new UTF8Writer(ctxt, out);

        // First, valid case, char by char
        w.write(0xD83D);
        w.write(0xDE03);
        w.close();
        assertEquals(4, out.size());
        final byte[] EXP_SURROGATES = new byte[] { (byte) 0xF0, (byte) 0x9F,
               (byte) 0x98, (byte) 0x83 };
        Assert.assertArrayEquals(EXP_SURROGATES, out.toByteArray());

        // and then as String
        ctxt = new IOContext(rec, null, false);
        out = new ByteArrayOutputStream();
        w = new UTF8Writer(ctxt, out);
        w.write("\uD83D\uDE03");
        w.close();
        assertEquals(4, out.size());
        Assert.assertArrayEquals(EXP_SURROGATES, out.toByteArray());
    }

    @SuppressWarnings("resource")
    public void testSurrogatesFail() throws Exception
    {
        BufferRecycler rec = new BufferRecycler();
        IOContext ctxt;
        ByteArrayOutputStream out;
        UTF8Writer w;

        ctxt = new IOContext(rec, null, false);
        out = new ByteArrayOutputStream();
        w = new UTF8Writer(ctxt, out);
        try {
            w.write(0xDE03);
            fail("should not pass");
        } catch (IOException e) {
            verifyException(e, "Unmatched second part");
        }

        ctxt = new IOContext(rec, null, false);
        out = new ByteArrayOutputStream();
        w = new UTF8Writer(ctxt, out);
        w.write(0xD83D);
        try {
            w.write('a');
            fail("should not pass");
        } catch (IOException e) {
            verifyException(e, "Broken surrogate pair");
        }

        ctxt = new IOContext(rec, null, false);
        out = new ByteArrayOutputStream();
        w = new UTF8Writer(ctxt, out);
        try {
            w.write("\uDE03");
            fail("should not pass");
        } catch (IOException e) {
            verifyException(e, "Unmatched second part");
        }
        
        ctxt = new IOContext(rec, null, false);
        out = new ByteArrayOutputStream();
        w = new UTF8Writer(ctxt, out);
        try {
            w.write("\uD83Da");
            fail("should not pass");
        } catch (IOException e) {
            verifyException(e, "Broken surrogate pair");
        }
    }
}