fix: do not add metadata to leaves (#193)

When an imported file is big enough to need leaf nodes, and that
file is imported with metadata, we should only add that metadata
to the root of the file DAG and not to every leaf in the graph.

packages/ipfs-unixfs-exporter/test/importer.spec.js

@@ -1045,6 +1045,34 @@ strategies.forEach((strategy) => {
       const node2 = await exporter(entries[1].cid, block)
       expect(node2).to.have.nested.property('unixfs.mode', 0o0755)
     })
+
+    it('should only add metadata to the root node of a file', async () => {
+      this.timeout(60 * 1000)
+
+      const mtime = { secs: 5000, nsecs: 0 }
+
+      const entries = await all(importer([{
+        path: '/foo/file1.txt',
+        content: asAsyncIterable(bigFile),
+        mtime
+      }], block))
+
+      const root = await exporter(entries[0].cid, block)
+      expect(root).to.have.deep.nested.property('unixfs.mtime', mtime)
+
+      if (root.node instanceof Uint8Array) {
+        throw new Error('Root node was not large enough to have children')
+      }
+
+      const child = await exporter(root.node.Links[0].Hash, block)
+
+      if (child.type !== 'file') {
+        throw new Error('Child node was wrong type')
+      }
+
+      expect(child).to.have.property('unixfs')
+      expect(child).to.not.have.nested.property('unixfs.mtime')
+    })
   })
 })
 

packages/ipfs-unixfs-importer/src/dag-builder/file/buffer-importer.js

@@ -30,9 +30,7 @@ async function * bufferImporter (file, block, options) {
       } else {
         unixfs = new UnixFS({
           type: options.leafType,
-          data: buffer,
-          mtime: file.mtime,
-          mode: file.mode
+          data: buffer
         })
 
         buffer = dagPb.encode({