Bump IfExists methods

src/main/java/com/github/marschall/memoryfilesystem/MemoryFileSystemProvider.java

@@ -343,6 +343,13 @@ public void delete(Path path) throws IOException {
     memoryFileSystem.delete(abstractPath);
   }
 
+  @Override
+  public boolean deleteIfExists(Path path) throws IOException {
+    AbstractPath abstractPath = castPath(path);
+    // FIXME
+    return false;
+  }
+
   @Override
   public void copy(Path source, Path target, CopyOption... options) throws IOException {
     this.copyOrMove(source, target, TwoPathOperation.COPY, options);
@@ -429,6 +436,18 @@ public void checkAccess(Path path, AccessMode... modes) throws IOException {
     memoryFileSystem.checkAccess(abstractPath, modes);
   }
 
+  // new with JDK 20
+  @Override
+  public boolean exists(Path path, LinkOption... options) {
+    return false;
+  }
+
+  // new with JDK 20
+  @Override
+  public <A extends BasicFileAttributes> A readAttributesIfExists(Path path, Class<A> type, LinkOption... options) throws IOException {
+    return null;
+  }
+
   @Override
   public <V extends FileAttributeView> V getFileAttributeView(Path path, Class<V> type, LinkOption... options) {
     AbstractPath abstractPath = castPath(path);

src/test/java/com/github/marschall/memoryfilesystem/MemoryFileSystemTest.java

@@ -46,6 +46,7 @@
 import java.nio.channels.NonWritableChannelException;
 import java.nio.channels.OverlappingFileLockException;
 import java.nio.channels.SeekableByteChannel;
+import java.nio.file.DirectoryNotEmptyException;
 import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.FileStore;
 import java.nio.file.FileSystem;
@@ -882,17 +883,54 @@ void readSymlinkLoop() throws IOException {
             "loop");
   }
 
-
-
   @Test
   void dontDeleteOpenFile() throws IOException {
     FileSystem fileSystem = this.extension.getFileSystem();
     Path path = fileSystem.getPath("test");
     try (SeekableByteChannel channel = Files.newByteChannel(path, CREATE_NEW, WRITE)) {
       assertThrows(FileSystemException.class , () -> Files.delete(path), "you shound't be able to delete a file wile it's open");
+      assertThrows(FileSystemException.class , () -> Files.deleteIfExists(path), "you shound't be able to delete a file wile it's open");
     }
   }
 
+  @Test
+  void delete() throws IOException {
+    FileSystem fileSystem = this.extension.getFileSystem();
+    Path directory = fileSystem.getPath("directory");
+    Path path = directory.resolve("test");
+    assertSame(directory, Files.createDirectory(directory));
+    assertSame(path, Files.createFile(path));
+
+    assertThrows(DirectoryNotEmptyException.class, () -> Files.delete(directory), "you shound't be able to delete a non-emtpy directory");
+
+    Files.delete(path);
+    assertThat(path, not(exists()));
+    assertThrows(NoSuchFileException.class, () -> Files.delete(path), "you shound't be able to delete a non-existing file");
+
+    Files.delete(directory);
+    assertThat(directory, not(exists()));
+    assertThrows(NoSuchFileException.class, () -> Files.delete(directory), "you shound't be able to delete a non-existing directory");
+  }
+
+  @Test
+  void deleteIfExists() throws IOException {
+    FileSystem fileSystem = this.extension.getFileSystem();
+    Path directory = fileSystem.getPath("directory");
+    Path path = directory.resolve("test");
+    assertSame(directory, Files.createDirectory(directory));
+    assertSame(path, Files.createFile(path));
+
+    assertThrows(DirectoryNotEmptyException.class, () -> Files.delete(directory), "you shound't be able to delete a non-emtpy directory");
+
+    assertTrue(Files.deleteIfExists(path));
+    assertThat(path, not(exists()));
+    assertFalse(Files.deleteIfExists(path));
+
+    assertTrue(Files.deleteIfExists(directory));
+    assertThat(directory, not(exists()));
+    assertFalse(Files.deleteIfExists(directory));
+  }
+
   @Test
   void inputStream() throws IOException {
     FileSystem fileSystem = this.extension.getFileSystem();