test/jdk/java/io/Reader/ReadAll.java

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/* @test
 * @bug 8354724
 * @summary Test Reader readAllLines and readAllAstring methods
 * @library .. /test/lib
 * @build jdk.test.lib.Platform jdk.test.lib.RandomFactory
 * @run junit ReadAll
 * @key randomness
 */

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import jdk.test.lib.RandomFactory;

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class ReadAll {
    private static final String PHRASE =
        "Ange plein de gaieté, connaissez-vous l'angoisse";

    private static File file;
    private static Path path;
    private static Random rnd;

    @BeforeAll
    public static void setup() throws IOException {
        path = Files.createTempFile(Path.of("."), "foo", "bar");
        file = path.toFile();

        rnd = RandomFactory.getRandom();
        int size = rnd.nextInt(2, 16386);

        int plen = PHRASE.length();
        List<String> strings = new ArrayList<String>(size);
        while (strings.size() < size) {
            int fromIndex = rnd.nextInt(0, plen / 2);
            int toIndex = rnd.nextInt(fromIndex, plen);
            strings.add(PHRASE.substring(fromIndex, toIndex));
        }
        Files.write(path, strings);
        System.out.println(strings.size() + " lines written");
    }

    @AfterAll
    public static void cleanup() throws IOException {
        if (file != null)
            file.delete();
    }

    @Test
    public void readAllLines() throws IOException {
        // Reader implementation
        List<String> lines;
        try (FileReader fr = new FileReader(file)) {
            lines = fr.readAllLines();
        }
        System.out.println(lines.size() + " lines read");

        List<String> linesExpected = Files.readAllLines(path);
        assertEquals(linesExpected, lines);

        // Reader.of implementation
        String stringExpected = Files.readString(path);
        int n = rnd.nextInt(stringExpected.length()/2);
        String substringExpected = stringExpected.substring(n);
        linesExpected = substringExpected.lines().toList();
        try (Reader r = new StringReader(stringExpected)) {
            r.skip(n);
            lines = r.readAllLines();
        }
        assertEquals(linesExpected, lines);
    }

    @Test
    public void readAllAsString() throws IOException {
        // Reader implementation
        String string;
        try (FileReader fr = new FileReader(file)) {
            string = fr.readAllAsString();
        }
        String stringExpected = Files.readString(path);
        assertEquals(stringExpected, string);

        // Reader.of implementation
        int n = rnd.nextInt(stringExpected.length()/2);
        try (Reader r = Reader.of(stringExpected)) {
            r.skip(n);
            string = r.readAllAsString();
        }
        assertEquals(stringExpected.substring(n), string);
    }
}