refactor(#2787): minimum nvim version 0.8 -> 0.9

Author: alex-courtis

README.md

@@ -28,7 +28,7 @@ Questions and general support: [Discussions](https://github.com/nvim-tree/nvim-t
 
 ## Requirements
 
-[neovim >=0.8.0](https://github.com/neovim/neovim/wiki/Installing-Neovim)
+[neovim >=0.9.0](https://github.com/neovim/neovim/wiki/Installing-Neovim)
 
 [nvim-web-devicons](https://github.com/nvim-tree/nvim-web-devicons) is optional and used to display file icons. It requires a [patched font](https://www.nerdfonts.com/). Your terminal emulator must be configured to use that font, usually "Hack Nerd Font"
 

doc/nvim-tree-lua.txt

@@ -103,7 +103,7 @@ Git Integration
 
 Requirements
 
-    This file explorer requires `neovim >= 0.8.0`
+    This file explorer requires `neovim >= 0.9.0`
 
 ==============================================================================
  2. QUICKSTART                                          *nvim-tree-quickstart*
@@ -832,7 +832,6 @@ Use nvim-tree in a floating window.
 
 Highlight precedence, additive:
   git < opened < modified < bookmarked < diagnostics < copied < cut
-Neovim <= 0.8 will only show the highest.
 
 *nvim-tree.renderer.add_trailing*
 Appends a trailing slash to folder names.

lua/nvim-tree.lua

@@ -11,7 +11,6 @@ local core = require "nvim-tree.core"
 local git = require "nvim-tree.git"
 local filters = require "nvim-tree.explorer.filters"
 local buffers = require "nvim-tree.buffers"
-local events = require "nvim-tree.events"
 local notify = require "nvim-tree.notify"
 
 local _config = {}
@@ -338,21 +337,6 @@ local function setup_autocommands(opts)
       end,
     })
   end
-
-  -- TODO #1545 remove similar check from view.resize
-  if vim.fn.has "nvim-0.9" == 1 then
-    create_nvim_tree_autocmd("WinResized", {
-      callback = function()
-        if vim.v.event and vim.v.event.windows then
-          for _, winid in ipairs(vim.v.event.windows) do
-            if vim.api.nvim_win_is_valid(winid) and utils.is_nvim_tree_buf(vim.api.nvim_win_get_buf(winid)) then
-              events._dispatch_on_tree_resize(vim.api.nvim_win_get_width(winid))
-            end
-          end
-        end
-      end,
-    })
-  end
 end
 
 local DEFAULT_OPTS = { -- BEGIN_DEFAULT_OPTS

lua/nvim-tree/appearance/init.lua

@@ -183,15 +183,8 @@ function M.setup()
 
   -- hard link override when legacy only is present
   for from, to in pairs(M.LEGACY_LINKS) do
-    local hl_from
-    local hl_to
-    if vim.fn.has "nvim-0.9" == 1 then
-      hl_from = vim.api.nvim_get_hl(0, { name = from })
-      hl_to = vim.api.nvim_get_hl(0, { name = to })
-    else
-      hl_from = vim.api.nvim__get_hl_defs(0)[from] or {}
-      hl_to = vim.api.nvim__get_hl_defs(0)[to] or {}
-    end
+    local hl_from = vim.api.nvim_get_hl(0, { name = from })
+    local hl_to = vim.api.nvim_get_hl(0, { name = to })
     if vim.tbl_isempty(hl_from) and not vim.tbl_isempty(hl_to) then
       vim.api.nvim_command("hi link " .. from .. " " .. to)
     end

lua/nvim-tree/renderer/builder.lua

@@ -295,24 +295,16 @@ function Builder:add_highlights(node)
     table.insert(name_groups, name)
   end
 
-  -- one or many icon groups; <= 0.8 always uses highest due to lack of a practical nvim_get_hl equivalent
+  -- one or many icon groups
   if #icon_groups > 1 then
-    if vim.fn.has "nvim-0.9" == 1 then
-      icon_hl_group = self:create_combined_group(icon_groups)
-    else
-      icon_hl_group = icon_groups[#icon_groups]
-    end
+    icon_hl_group = self:create_combined_group(icon_groups)
   else
     icon_hl_group = icon_groups[1]
   end
 
-  -- one or many name groups; <= 0.8 always uses highest due to lack of a practical nvim_get_hl equivalent
+  -- one or many name groups
   if #name_groups > 1 then
-    if vim.fn.has "nvim-0.9" == 1 then
-      name_hl_group = self:create_combined_group(name_groups)
-    else
-      name_hl_group = name_groups[#name_groups]
-    end
+    name_hl_group = self:create_combined_group(name_groups)
   else
     name_hl_group = name_groups[1]
   end

lua/nvim-tree/view.lua

@@ -348,11 +348,7 @@ function M.resize(size)
   local new_size = get_width()
   vim.api.nvim_win_set_width(M.get_winnr() or 0, new_size)
 
-  -- TODO #1545 remove similar check from setup_autocommands
-  -- We let nvim handle sending resize events after 0.9
-  if vim.fn.has "nvim-0.9" == 0 then
-    events._dispatch_on_tree_resize(new_size)
-  end
+  events._dispatch_on_tree_resize(new_size)
 
   if not M.View.preserve_window_proportions then
     vim.cmd ":wincmd ="