Add node "badge" support

The "badge" is an area to indicate the node status.
It is mainly desigend for git status integration but not limited for that.

Author: lambdalisue

autoload/fern/internal/node.vim

@@ -207,6 +207,7 @@ endfunction
 function! s:new(node, ...) abort
   let node = extend(a:node, {
         \ 'label': get(a:node, 'label', a:node.name),
+        \ 'badge': get(a:node, 'badge', ''),
         \ 'hidden': get(a:node, 'hidden', 0),
         \ 'bufname': get(a:node, 'bufname', v:null),
         \ 'concealed': get(a:node, 'concealed', {}),

autoload/fern/renderer/default.vim

@@ -51,9 +51,10 @@ function! s:syntax() abort
         \ escape(g:fern#renderer#default#collapsed_symbol, s:ESCAPE_PATTERN),
         \ escape(g:fern#renderer#default#expanded_symbol, s:ESCAPE_PATTERN),
         \)
-  syntax match FernRootText   /.*$/ contained
-  syntax match FernLeafText   /.*$/ contained
-  syntax match FernBranchText /.*$/ contained
+  syntax match FernRootText   /.*\ze .*$/ contained nextgroup=FernBadge
+  syntax match FernLeafText   /.*\ze .*$/ contained nextgroup=FernBadge
+  syntax match FernBranchText /.*\ze .*$/ contained nextgroup=FernBadge
+  syntax match FernBadge      /.*/        contained
 endfunction
 
 function! s:highlight() abort
@@ -68,15 +69,15 @@ endfunction
 function! s:render_node(node, base, options) abort
   let level = len(a:node.__key) - a:base
   if level is# 0
-    return prefix . a:options.root_symbol . a:node.label
+    return a:options.root_symbol . a:node.label . ' ' . a:node.badge
   endif
   let leading = repeat(a:options.leading, level - 1)
   let symbol = a:node.status is# s:STATUS_NONE
         \ ? a:options.leaf_symbol
         \ : a:node.status is# s:STATUS_COLLAPSED
         \   ? a:options.collapsed_symbol
         \   : a:options.expanded_symbol
-  return prefix . leading . symbol . a:node.label
+  return leading . symbol . a:node.label . ' ' . a:node.badge
 endfunction
 
 call s:Config.config(expand('<sfile>:p'), {

doc/fern-develop.txt

@@ -110,6 +110,9 @@ A node instance is a tree item which has the following attributes:
 
 "label"		A |String| used to display the node in a tree view.
 
+"badge"		A |String| used to display the node badge in a tree view.
+		Only first character is used in the default renderer.
+
 "hidden"	A 1/0 to indicate if the node should be hidden. All hidden
 		nodes become visible once fern enter hidden mode.