[FIX] same behavior but semantically correct

src/Gargantext/Components/Forest/Tree.purs

@@ -200,7 +200,7 @@ toHtml p@{ asyncTasks
         let withId (NTree (LNode {id: id'}) _) = id'
 
         pure $ H.li {} $
-          [ nodeMainSpan (isLeaf ary) 
+          [ nodeMainSpan (A.null ary) 
                          { id
                          , dispatch: pAction
                          , folderOpen
@@ -224,8 +224,6 @@ toHtml p@{ asyncTasks
                           }
                         )
 
-isLeaf :: Array FTree -> Boolean
-isLeaf = not <<< A.null
 
 type ChildNodesProps =
   ( asyncTasks :: R.State GAT.Storage

src/Gargantext/Components/Forest/Tree/Node.purs

@@ -128,7 +128,8 @@ nodeMainSpan isLeaf p@{ dispatch, folderOpen, frontends, handed, session } = R.c
 
     chevronIcon isLeaf handed' nodeType folderOpen'@(open /\ _) =
       if isLeaf
-         then
+         then H.div {} []
+         else
            H.a { className: "chevron-icon"
                , onClick: R2.effToggler folderOpen'
                }
@@ -139,7 +140,6 @@ nodeMainSpan isLeaf p@{ dispatch, folderOpen, frontends, handed, session } = R.c
                                       then "fa fa-chevron-right"
                                       else "fa fa-chevron-left"
                     } [] ]
-           else H.div {} []
 
     folderIcon nodeType folderOpen'@(open /\ _) =
       H.a { className: "folder-icon"