SymlinkTest.java

package com.example;

import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.file.Files;

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

class SymlinkTest {

    private final File baseDir = new File("/home/guido/work");
    private final File linkDir = new File(baseDir, "path/to");
    private final File link = new File(linkDir, "symlink");

    @BeforeEach
    void setUp() {
        if (!linkDir.exists()) {
            linkDir.mkdirs();
        }
    }

    @AfterEach
    void tearDown() {
        link.delete();
        linkDir.delete();
        new File(baseDir, "path").delete();
    }

    @Test
    void runCommandInSymlinkDir() throws IOException {
        Files.createSymbolicLink(link.toPath(), baseDir.toPath());

        Process process = new ProcessBuilder()
                .command("pwd")
                .directory(link)
                .start();
        String output = getOutput(process);

        assertEquals(link.getAbsolutePath(), output);
    }
    
    @Test
    void runCommandInShell() throws IOException {
        Files.createSymbolicLink(link.toPath(), baseDir.toPath());

        String[] cmd = {"/bin/sh", "-c", "cd " + link + " && pwd"};
        Process process = Runtime.getRuntime().exec(cmd);
        String output = getOutput(process);

        assertEquals(link.getAbsolutePath(), output);
    }

    private String getOutput(Process process) throws IOException {
        BufferedReader reader = new BufferedReader(
                new InputStreamReader(process.getInputStream()));

        return reader.readLine();
    }
}