add test

to check whether loading `.so` or `.dylib` from `java.library.path` works, when not calling `FuseBuilder.setLibraryPath(...)`

jfuse-tests/src/test/java/org/cryptomator/jfuse/tests/FallbackLibLoadingIT.java

@@ -0,0 +1,49 @@
+package org.cryptomator.jfuse.tests;
+
+import org.cryptomator.jfuse.api.Fuse;
+import org.cryptomator.jfuse.examples.RandomFileSystem;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledIfSystemProperty;
+import org.junit.jupiter.api.condition.EnabledIfSystemProperty;
+import org.junit.jupiter.api.condition.EnabledOnOs;
+import org.junit.jupiter.api.condition.OS;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.concurrent.TimeoutException;
+
+@EnabledIfSystemProperty(named = "fuse.lib.path", matches = ".+")
+public class FallbackLibLoadingIT {
+
+	@Test
+	@EnabledOnOs(OS.LINUX)
+	@DisplayName("loads fuse lib from java.library.path, if not calling FuseBuilder.setLibraryPath(...)")
+	public void loadFromJavaLibraryPathOnLinux(@TempDir Path p) throws IOException, TimeoutException {
+		loadFromJavaLibraryPath(p, "libfuse3.so");
+	}
+
+	@Test
+	@EnabledOnOs(OS.MAC)
+	@DisplayName("loads fuse lib from java.library.path, if not calling FuseBuilder.setLibraryPath(...)")
+	public void loadFromJavaLibraryPathOnMacOS(@TempDir Path p) throws IOException, TimeoutException {
+		loadFromJavaLibraryPath(p, "libfuse-t.dylib");
+	}
+
+	private void loadFromJavaLibraryPath(Path tmpLibPath, String libFileName) throws IOException, TimeoutException {
+		var libPath = System.getProperty("fuse.lib.path");
+		var symlinkPath = tmpLibPath.resolve(libFileName);
+		Files.createSymbolicLink(symlinkPath, Path.of(libPath));
+
+		System.setProperty("java.library.path", tmpLibPath.toString());
+
+		var builder = Fuse.builder();
+		var fs = new RandomFileSystem(builder.errno());
+		var fuse = Assertions.assertDoesNotThrow(() -> builder.build(fs));
+		fuse.close();
+	}
+
+}