feat: use nvim_buf_set_extmark for vim.highlight (#16963)

Closes https://github.com/neovim/neovim/issues/13647

This allows customizing the priority of the highlights.

* Add default priority of 50
* Use priority of 200 for highlight on yank
* use priority of 40 for highlight references (LSP)

runtime/lua/vim/highlight.lua

@@ -25,16 +25,29 @@ end
 ---@param higroup highlight group to use for highlighting
 ---@param rtype type of range (:help setreg, default charwise)
 ---@param inclusive boolean indicating whether the range is end-inclusive (default false)
-function highlight.range(bufnr, ns, higroup, start, finish, rtype, inclusive)
+---@param priority number indicating priority of highlight (default 50)
+function highlight.range(bufnr, ns, higroup, start, finish, rtype, inclusive, priority)
   rtype = rtype or 'v'
   inclusive = inclusive or false
+  priority = priority or 50
 
   -- sanity check
   if start[2] < 0 or finish[1] < start[1] then return end
 
   local region = vim.region(bufnr, start, finish, rtype, inclusive)
   for linenr, cols in pairs(region) do
-    api.nvim_buf_add_highlight(bufnr, ns, higroup, linenr, cols[1], cols[2])
+    local end_row
+    if cols[2] == -1 then
+      end_row = linenr + 1
+      cols[2] = 0
+    end
+    api.nvim_buf_set_extmark(bufnr, ns, linenr, cols[1], {
+      hl_group = higroup,
+      end_row = end_row,
+      end_col = cols[2],
+      priority = priority,
+      strict = false
+    })
   end
 
 end
@@ -82,7 +95,7 @@ function highlight.on_yank(opts)
   pos1 = {pos1[2] - 1, pos1[3] - 1 + pos1[4]}
   pos2 = {pos2[2] - 1, pos2[3] - 1 + pos2[4]}
 
-  highlight.range(bufnr, yank_ns, higroup, pos1, pos2, event.regtype, event.inclusive)
+  highlight.range(bufnr, yank_ns, higroup, pos1, pos2, event.regtype, event.inclusive, 200)
 
   vim.defer_fn(
     function()

runtime/lua/vim/lsp/util.lua

@@ -1550,7 +1550,10 @@ do --[[ References ]]
                       reference_ns,
                       document_highlight_kind[kind],
                       { start_line, start_idx },
-                      { end_line, end_idx })
+                      { end_line, end_idx },
+                      nil,
+                      false,
+                      40)
     end
   end
 end

test/functional/lua/diagnostic_spec.lua

@@ -208,10 +208,10 @@ describe('vim.diagnostic', function()
     eq(all_highlights, exec_lua [[
       local ns_1_diags = {
         make_error("Error 1", 1, 1, 1, 5),
-        make_warning("Warning on Server 1", 2, 1, 2, 5),
+        make_warning("Warning on Server 1", 2, 1, 2, 3),
       }
       local ns_2_diags = {
-        make_warning("Warning 1", 2, 1, 2, 5),
+        make_warning("Warning 1", 2, 1, 2, 3),
       }
 
       vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, ns_1_diags)
@@ -255,10 +255,10 @@ describe('vim.diagnostic', function()
     eq({0, 2}, exec_lua [[
       local ns_1_diags = {
         make_error("Error 1", 1, 1, 1, 5),
-        make_warning("Warning on Server 1", 2, 1, 2, 5),
+        make_warning("Warning on Server 1", 2, 1, 2, 3),
       }
       local ns_2_diags = {
-        make_warning("Warning 1", 2, 1, 2, 5),
+        make_warning("Warning 1", 2, 1, 2, 3),
       }
 
       vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, ns_1_diags)
@@ -599,10 +599,10 @@ describe('vim.diagnostic', function()
       eq(all_highlights, exec_lua [[
         local ns_1_diags = {
           make_error("Error 1", 1, 1, 1, 5),
-          make_warning("Warning on Server 1", 2, 1, 2, 5),
+          make_warning("Warning on Server 1", 2, 1, 2, 3),
         }
         local ns_2_diags = {
-          make_warning("Warning 1", 2, 1, 2, 5),
+          make_warning("Warning 1", 2, 1, 2, 3),
         }
 
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, ns_1_diags)
@@ -787,7 +787,7 @@ describe('vim.diagnostic', function()
       eq(2, exec_lua [[
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
           make_error("Error 1", 1, 1, 1, 5),
-          make_warning("Warning on Server 1", 1, 1, 2, 5),
+          make_warning("Warning on Server 1", 1, 1, 2, 3),
         })
 
         return #vim.diagnostic.get(diagnostic_bufnr)
@@ -798,9 +798,9 @@ describe('vim.diagnostic', function()
       eq({2, 3, 2}, exec_lua [[
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
           make_error("Error 1", 1, 1, 1, 5),
-          make_warning("Warning on Server 1", 1, 1, 2, 5),
+          make_warning("Warning on Server 1", 1, 1, 2, 3),
-          make_info("Ignored information", 1, 1, 2, 5),
+          make_info("Ignored information", 1, 1, 2, 3),
-          make_hint("Here's a hint", 1, 1, 2, 5),
+          make_hint("Here's a hint", 1, 1, 2, 3),
         })
 
         return {
@@ -820,8 +820,8 @@ describe('vim.diagnostic', function()
       eq(1, exec_lua [[
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
           make_error("Error 1", 1, 1, 1, 5),
-          make_warning("Warning on Server 1", 1, 1, 2, 5),
+          make_warning("Warning on Server 1", 1, 1, 2, 3),
-          make_info("Ignored information", 1, 1, 2, 5),
+          make_info("Ignored information", 1, 1, 2, 3),
           make_error("Error On Other Line", 2, 1, 1, 5),
         })