feat: nvim lsp integration (#260)

README.md

@@ -36,6 +36,7 @@ let g:nvim_tree_disable_netrw = 0 "1 by default, disables netrw
 let g:nvim_tree_hijack_netrw = 0 "1 by default, prevents netrw from automatically opening when opening directories (but lets you keep its other utilities)
 let g:nvim_tree_add_trailing = 1 "0 by default, append a trailing slash to folder names
 let g:nvim_tree_group_empty = 1 " 0 by default, compact folders that only contain a single folder into one node in the file tree
+let g:nvim_tree_lsp_diagnostics = 1 "0 by default, will show lsp diagnostics in the tree. See :help nvim_tree_lsp_diagnostics
 let g:nvim_tree_show_icons = {
     \ 'git': 1,
     \ 'folders': 0,
@@ -173,6 +174,7 @@ This plugin is very fast because it uses the `libuv` `scandir` and `scandir_next
 - Change directory with `.`
 - Add / Rename / delete files
 - Git integration (icons and file highlight)
+- Lsp diagnostics integration (file highlight)
 - Indent markers
 - Mouse support
 - It's fast

doc/nvim-tree-lua.txt

@@ -220,6 +220,12 @@ Can be 0 or 1. When 1, appends a trailing slash to folder names.
 Can be 0 or 1. When 1, folders that contain only one folder are grouped
 together. 0 by default.
 
+|g:nvim_tree_lsp_diagnostics|         *g:nvim_tree_lsp_diagnostics*
+
+Can be 0 or 1. When 1, will show nvim-lsp diagnostics in the tree
+by highlighting filenames with `NvimTreeLspDiagnostics`.
+Code will be executed on `BufWritePost`. 0 by default.
+
 ==============================================================================
 INFORMATIONS				        *nvim-tree-info*
 
@@ -360,6 +366,7 @@ NvimTreeSpecialFile
 NvimTreeImageFile
 NvimTreeMarkdownFile
 NvimTreeIndentMarker
+NvimTreeLspDiagnostics
 
 NvimTreeLicenseIcon
 NvimTreeYamlIcon

lua/nvim-tree/colors.lua

@@ -34,6 +34,7 @@ local function get_hl_groups()
     Symlink = { gui = 'bold', fg = colors.cyan },
     FolderIcon = { fg = '#8094b4' },
     RootFolder = { fg = colors.purple },
+    LspDiagnostics = { gui = 'underline' },
 
     ExecFile = { gui = 'bold', fg = colors.green },
     SpecialFile = { gui = 'bold,underline', fg = colors.yellow },
@@ -74,8 +75,9 @@ function M.setup()
   end
   local higlight_groups = get_hl_groups()
   for k, d in pairs(higlight_groups) do
-    local gui = d.gui or 'NONE'
+    local gui = d.gui and ' gui='..d.gui or ''
-    api.nvim_command('hi def NvimTree'..k..' gui='..gui..' guifg='..d.fg)
+    local fg = d.fg and ' guifg='..d.fg or ''
+    api.nvim_command('hi def NvimTree'..k..gui..fg)
   end
 
   local links = get_links()

lua/nvim-tree/diagnostics.lua

@@ -0,0 +1,49 @@
+local a = vim.api
+local utils = require'nvim-tree.utils'
+local get_diagnostics = vim.lsp.diagnostic.get_all
+
+local M = {}
+
+local function get_severity(diagnostics)
+  for _, v in ipairs(diagnostics) do
+    if v.severity > 0 then
+      return v.severity
+    end
+  end
+  return 0
+end
+
+local function highlight_node(node, linenr)
+  local buf = require'nvim-tree.lib'.Tree.bufnr
+  if not vim.fn.bufexists(buf) or not vim.fn.bufloaded(buf) then return end
+  local line = a.nvim_buf_get_lines(buf, linenr, linenr+1, false)[1]
+  local starts_at = vim.fn.stridx(line, node.name)
+  a.nvim_buf_add_highlight(buf, -1, 'NvimTreeLspDiagnostics', linenr, starts_at, -1)
+end
+
+
+function M.update()
+  local buffer_severity = {}
+
+  for buf, diagnostics in pairs(get_diagnostics()) do
+    local bufname = a.nvim_buf_get_name(buf)
+    if not buffer_severity[bufname] then
+      local severity = get_severity(diagnostics)
+      buffer_severity[bufname] = severity
+    end
+  end
+
+  vim.defer_fn(function()
+    local nodes = require'nvim-tree.lib'.Tree.entries
+    for bufname, severity in pairs(buffer_severity) do
+      if severity > 0 then
+        local node, line = utils.find_node(nodes, function(node)
+          return node.absolute_path == bufname
+        end)
+        if node then highlight_node(node, line) end
+      end
+    end
+  end, 100)
+end
+
+return M

lua/nvim-tree/utils.lua

@@ -64,4 +64,22 @@ function M.path_remove_trailing(path)
 end
 
 M.path_separator = path_separator
+
+-- get the node from the tree that matches the predicate
+-- @param nodes list of node
+-- @param fn    function(node): boolean
+function M.find_node(nodes, fn)
+  local i = 1
+  for _, node in ipairs(nodes) do
+    if fn(node) then return node, i end
+    if node.open and #node.entries > 0 then
+      local n, idx = M.find_node(node.entries, fn)
+      i = i + idx
+      if n then return n, i end
+    end
+    i = i + 1
+  end
+  return nil, i
+end
+
 return M

plugin/tree.vim

@@ -13,6 +13,9 @@ augroup NvimTree
     silent! autocmd! FileExplorer *
   endif
   au BufWritePost * lua require'nvim-tree'.refresh()
+  if get(g:, 'nvim_tree_lsp_diagnostics', 0) == 1
+    au BufWritePost * lua require'nvim-tree.diagnostics'.update()
+  endif
   au BufEnter * lua require'nvim-tree'.buf_enter()
   if get(g:, 'nvim_tree_auto_close') == 1
     au WinClosed * lua require'nvim-tree'.on_leave()