fix: DirBuilder::is_empty

unixfs/src/dir/builder/buffered.rs

@@ -123,7 +123,7 @@ impl BufferingTreeBuilder {
             }
 
             // our first level can be full given the options
-            let full = depth == 0 && !self.opts.wrap_with_directory && dir_builder.is_empty();
+            let full = depth == 0 && !self.opts.wrap_with_directory && !dir_builder.is_empty();
 
             if last {
                 let mut next_id = Some(*counter);

unixfs/src/dir/builder/dir_builder.rs

@@ -69,7 +69,7 @@ impl DirBuilder {
     }
 
     pub fn is_empty(&self) -> bool {
-        self.len() != 0
+        self.len() == 0
     }
 
     pub fn set_metadata(&mut self, metadata: Metadata) {