CrossingStarsTest

import junit.framework.TestCase;

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;

public class CrossingStarsTest extends TestCase {

    private static void printCrossingStars(final int n) {
        // Your implementation here.
    }

    public void test0() {
        assertOutputEquals(new String[] {
                }, 0);
    }

    public void test1() {
        assertOutputEquals(new String[] {
                        " *",
                        "**",
                        " *",
                }, 1);
    }

    public void test2() {
        assertOutputEquals(new String[] {
                        "    *",
                        " *  *",
                        "*****",
                        " *  *",
                        "    *",
                }, 2);
    }

    public void test3() {
        assertOutputEquals(new String[] {
                        "        *",
                        "    *   *",
                        " *  *   *",
                        "*********",
                        " *  *   *",
                        "    *   *",
                        "        *",
                }, 3);
    }

    public void test4() {
        assertOutputEquals(new String[] {
                        "             *",
                        "        *    *",
                        "    *   *    *",
                        " *  *   *    *",
                        "**************",
                        " *  *   *    *",
                        "    *   *    *",
                        "        *    *",
                        "             *",
                }, 4);
    }

    public void test5() {
        assertOutputEquals(new String[] {
                        "                   *",
                        "             *     *",
                        "        *    *     *",
                        "    *   *    *     *",
                        " *  *   *    *     *",
                        "********************",
                        " *  *   *    *     *",
                        "    *   *    *     *",
                        "        *    *     *",
                        "             *     *",
                        "                   *",
                }, 5);
    }

    private static void assertOutputEquals(final String[] expectedOutputLines, final int n) {
        final PrintStream oldSystemOut = System.out;
        final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        final PrintStream printStream = new PrintStream(byteArrayOutputStream);
        System.setOut(printStream);
        try {
            printCrossingStars(n);
        } finally {
            System.setOut(oldSystemOut);
            printStream.close();
        }

        final StringBuilder expectedOutputStringBuilder = new StringBuilder();
        for (final String line : expectedOutputLines) {
            expectedOutputStringBuilder.append(line).append(System.lineSeparator());
        }
        assertEquals(expectedOutputStringBuilder.toString(), byteArrayOutputStream.toString());
    }

}