add better lsp diagnostic integration

README.md

@@ -36,7 +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_lsp_diagnostics = 1 "0 by default, will show lsp diagnostics in the signcolumn. See :help nvim_tree_lsp_diagnostics
 let g:nvim_tree_show_icons = {
     \ 'git': 1,
     \ 'folders': 0,
@@ -174,7 +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)
+- Lsp diagnostics integration (signs)
 - Indent markers
 - Mouse support
 - It's fast

doc/nvim-tree-lua.txt

@@ -227,8 +227,8 @@ 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`.
+Can be 0 or 1. When 1, will show nvim-lsp diagnostics in the signcolumn
+of the tree highlighted by diagnostic severity.
 Code will be executed on `BufWritePost`. 0 by default.
 
 ==============================================================================
@@ -373,7 +373,11 @@ NvimTreeSpecialFile
 NvimTreeImageFile
 NvimTreeMarkdownFile
 NvimTreeIndentMarker
-NvimTreeLspDiagnostics
+
+LspDiagnosticsError
+LspDiagnosticsWarning
+LspDiagnosticsInformation
+LspDiagnosticsHint
 
 NvimTreeLicenseIcon
 NvimTreeYamlIcon

lua/nvim-tree/colors.lua

@@ -34,7 +34,6 @@ 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 },
@@ -68,6 +67,10 @@ local function get_links()
     FileDeleted = 'NvimTreeGitDeleted',
     Popup = 'Normal',
     GitIgnored = 'Comment',
+    LspDiagnosticsError = "LspDiagnosticsDefaultError",
+    LspDiagnosticsWarning = "LspDiagnosticsDefaultWarning",
+    LspDiagnosticsInformation = "LspDiagnosticsDefaultInformation",
+    LspDiagnosticsHint = "LspDiagnosticsDefaultHint",
   }
 end
 

lua/nvim-tree/diagnostics.lua

@@ -1,24 +1,38 @@
 local a = vim.api
 local utils = require'nvim-tree.utils'
+local view = require'nvim-tree.view'
 local get_diagnostics = vim.lsp.diagnostic.get_all
 
 local M = {}
 
-local function get_severity(diagnostics)
+local function get_highest_severity(diagnostics)
+  local severity = 0
   for _, v in ipairs(diagnostics) do
-    if v.severity > 0 then
-      return v.severity
+    if v.severity > severity then
+      severity = v.severity
     end
   end
-  return 0
+  return severity
 end
 
-local function highlight_node(node, linenr)
-  local buf = require'nvim-tree.view'.View.bufnr
+local sign_names = {
+  { "NvimTreeSignHint", "NvimTreeLspDiagnosticsHint" },
+  { "NvimTreeSignInformation", "NvimTreeLspDiagnosticsInformation" },
+  { "NvimTreeSignWarning", "NvimTreeLspDiagnosticsWarning" },
+  { "NvimTreeSignError", "NvimTreeLspDiagnosticsError" },
+}
+
+for _, v in ipairs(sign_names) do
+  vim.fn.sign_define(v[1], { text="⚠", texthl=v[2]})
+end
+
+local signs = {}
+
+local function add_sign(linenr, severity)
+  local buf = view.View.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)
+  local sign_name = sign_names[severity][1]
+  table.insert(signs, vim.fn.sign_place(1, 'NvimTreeDiagnosticSigns', sign_name, buf, { lnum = linenr+1 }))
 end
 
 function M.update()
@@ -27,22 +41,30 @@ function M.update()
   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)
+      local severity = get_highest_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
+  local nodes = require'nvim-tree.lib'.Tree.entries
+  if #signs then
+    vim.fn.sign_unplacelist(vim.tbl_map(function(sign)
+      return {
+        buffer = view.View.bufnr,
+        group = "NvimTreeDiagnosticSigns",
+        id = sign
+      }
+    end, signs))
+    signs = {}
+  end
+  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 add_sign(line, severity) end
     end
-  end, 100)
+  end
 end
 
 return M