DMDirc-Util/src/test/java/com/dmdirc/util/io/ReverseFileReaderTest.java

/*
 * Copyright (c) 2006-2017 DMDirc Developers
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
 * OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package com.dmdirc.util.io;

import java.io.IOException;
import java.net.URISyntaxException;
import java.nio.file.Paths;
import java.util.Stack;

import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class ReverseFileReaderTest {

    @Test
    public void testIndividual() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test1.txt").toURI()))) {
            assertEquals("Line 7", reader.getNextLine());
            assertEquals("Line 6", reader.getNextLine());
            assertEquals("Line 5", reader.getNextLine());
            assertEquals("Line 4", reader.getNextLine());
            assertEquals("Line 3", reader.getNextLine());
            assertEquals("Line 2", reader.getNextLine());
            assertEquals("Line 1", reader.getNextLine());
        }
    }

    @Test
    public void testCarriageReturn() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test4.txt").toURI()))) {
            reader.getNextLine();
            assertEquals("Normal line", reader.getNextLine());
        }
    }

    @Test
    public void testLongLine() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test4.txt").toURI()))) {
            assertEquals("This is a line that is longer than 50 characters, so " +
                            "should cause the reader to have to scan back multiple times.",
                    reader.getNextLine());
        }
    }

    @Test
    public void testStack() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test1.txt").toURI()))) {
            final Stack<String> lines = reader.getLines(10);

            assertEquals(7, lines.size());
            assertEquals("Line 1", lines.pop());
            assertEquals("Line 2", lines.pop());
            assertEquals("Line 3", lines.pop());
            assertEquals("Line 4", lines.pop());
            assertEquals("Line 5", lines.pop());
            assertEquals("Line 6", lines.pop());
            assertEquals("Line 7", lines.pop());
        }
    }

    @Test
    public void testSmallStack() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test1.txt").toURI()))) {
            final Stack<String> lines = reader.getLines(3);
            assertEquals(3, lines.size());
            assertEquals("Line 5", lines.pop());
            assertEquals("Line 6", lines.pop());
            assertEquals("Line 7", lines.pop());
        }
    }

    @Test
    public void testgetLinesAsString() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test5.txt").toURI()))) {
            final String lines = reader.getLinesAsString(3);
            assertEquals("Line 1\nLine 2\nLine 3\n", lines);
        }
    }

    @Test
    public void testgetLinesAsStringLeadingNewline() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test5.txt").toURI()))) {
            final String lines = reader.getLinesAsString(4);
            assertEquals("Line 1\nLine 2\nLine 3\n", lines);
        }
    }

    @Test
    public void testIllegalGetLinesAsString() throws IOException, URISyntaxException {
        final ReverseFileReader reader = new ReverseFileReader(
                Paths.get((getClass().getResource("test5.txt").toURI())));
        reader.close();
        final String lines = reader.getLinesAsString(4);
        assertEquals("", lines);
    }

    @Test
    public void testReset() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test1.txt").toURI()))) {
            assertEquals("Line 7", reader.getNextLine());
            assertEquals("Line 6", reader.getNextLine());
            reader.reset();
            assertEquals("Line 7", reader.getNextLine());
            assertEquals("Line 6", reader.getNextLine());
            assertEquals("Line 5", reader.getNextLine());
        }
    }

    public void testCloseIsIdempotent() throws URISyntaxException, IOException {
        final ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test1.txt").toURI()));
        reader.close();
        reader.close();
    }

    @Test(expected=IOException.class)
    public void testIllegalReset() throws URISyntaxException, IOException {
        final ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test1.txt").toURI()));
        reader.close();
        reader.reset();
    }

    @Test(expected=IOException.class)
    public void testIllegalGetNextLine() throws URISyntaxException, IOException {
        final ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test1.txt").toURI()));
        reader.close();
        reader.getNextLine();
    }

    @Test
    public void testSeekLength() throws IOException, URISyntaxException {
        try (ReverseFileReader reader = new ReverseFileReader(
                Paths.get(getClass().getResource("test1.txt").toURI()))) {
            reader.setSeekLength((byte) 100);
            assertEquals((byte) 100, reader.getSeekLength());
        }
    }

}