lsp: sort diagnostics by severity (#14372)

Allow to sort diagnostics (and thus signs and virtual text) by severity, so that
the most important message is shown first.

    vim.lsp.handlers['textDocument/publishDiagnostics'] = vim.lsp.with(
      vim.lsp.diagnostic.on_publish_diagnostics, {
        severity_sort = true,
      }
    )

Fixes https://github.com/neovim/neovim/issues/13929

1 files changed, 8 insertions, 4 deletions

diff --git a/runtime/lua/vim/lsp/diagnostic.lua b/runtime/lua/vim/lsp/diagnostic.lua
index e6132e78bf..dcd54fd587 100644
--- a/runtime/lua/vim/lsp/diagnostic.lua
+++ b/runtime/lua/vim/lsp/diagnostic.lua
@@ -406,9 +406,7 @@ function M.get_line_diagnostics(bufnr, line_nr, opts, client_id)
     line_diagnostics = filter_by_severity_limit(opts.severity_limit, line_diagnostics)
   end
 
-  if opts.severity_sort then
-    table.sort(line_diagnostics, function(a, b) return a.severity < b.severity end)
-  end
+  table.sort(line_diagnostics, function(a, b) return a.severity < b.severity end)
 
   return line_diagnostics
 end
@@ -997,6 +995,8 @@ end
 ---         - See |vim.lsp.diagnostic.set_signs()|
 ---     - update_in_insert: (default=false)
 ---         - Update diagnostics in InsertMode or wait until InsertLeave
+---     - severity_sort:    (default=false)
+---         - Sort diagnostics (and thus signs and virtual text)
 function M.on_publish_diagnostics(_, _, params, client_id, _, config)
   local uri = params.uri
   local bufnr = vim.uri_to_bufnr(uri)
@@ -1007,6 +1007,10 @@ function M.on_publish_diagnostics(_, _, params, client_id, _, config)
 
   local diagnostics = params.diagnostics
 
+  if if_nil(config.severity_sort, false) then
+    table.sort(diagnostics, function(a, b) return a.severity > b.severity end)
+  end
+
   -- Always save the diagnostics, even if the buf is not loaded.
   -- Language servers may report compile or build errors via diagnostics
   -- Users should be able to find these, even if they're in files which
@@ -1034,6 +1038,7 @@ function M.display(diagnostics, bufnr, client_id, config)
     underline = true,
     virtual_text = true,
     update_in_insert = false,
+    severity_sort = false,
   }, config)
 
   -- TODO(tjdevries): Consider how we can make this a "standardized" kind of thing for |lsp-handlers|.
@@ -1116,7 +1121,6 @@ end
 ---@return table {popup_bufnr, win_id}
 function M.show_line_diagnostics(opts, bufnr, line_nr, client_id)
   opts = opts or {}
-  opts.severity_sort = if_nil(opts.severity_sort, true)
 
   local show_header = if_nil(opts.show_header, true)