fix(diagnostic): support severity_sort

runtime/doc/diagnostic.txt

@@ -216,18 +216,31 @@ config({opts}, {namespace})                          *vim.diagnostic.config()*
                     {opts}       table Configuration table with the following
                                  keys:
                                  • underline: (default true) Use underline for
-                                   diagnostics
+                                   diagnostics. Options:
+                                   • severity: Only underline diagnostics
+                                     matching the given severity
+                                     |diagnostic-severity|
+
                                  • virtual_text: (default true) Use virtual
-                                   text for diagnostics
+                                   text for diagnostics. Options:
+                                   • severity: Only show virtual text for
+                                     diagnostics matching the given severity
+                                     |diagnostic-severity|
+
                                  • signs: (default true) Use signs for
-                                   diagnostics
+                                   diagnostics. Options:
+                                   • severity: Only show signs for diagnostics
+                                     matching the given severity
+                                     |diagnostic-severity|
+
                                  • update_in_insert: (default false) Update
                                    diagnostics in Insert mode (if false,
                                    diagnostics are updated on InsertLeave)
                                  • severity_sort: (default false) Sort
                                    diagnostics by severity. This affects the
                                    order in which signs and virtual text are
-                                   displayed
+                                   displayed. Options:
+                                   • reverse: (boolean) Reverse sort order
                     {namespace}  number|nil Update the options for the given
                                  namespace. When omitted, update the global
                                  diagnostic options.

runtime/lua/vim/diagnostic.lua

@@ -440,13 +440,20 @@ end
 ---         - `function`: Function with signature (namespace, bufnr) that returns any of the above.
 ---
 ---@param opts table Configuration table with the following keys:
----       - underline: (default true) Use underline for diagnostics
+---       - underline: (default true) Use underline for diagnostics. Options:
----       - virtual_text: (default true) Use virtual text for diagnostics
+---                    * severity: Only underline diagnostics matching the given severity
----       - signs: (default true) Use signs for diagnostics
+---                    |diagnostic-severity|
+---       - virtual_text: (default true) Use virtual text for diagnostics. Options:
+---                       * severity: Only show virtual text for diagnostics matching the given
+---                       severity |diagnostic-severity|
+---       - signs: (default true) Use signs for diagnostics. Options:
+---                * severity: Only show signs for diagnostics matching the given severity
+---                |diagnostic-severity|
 ---       - update_in_insert: (default false) Update diagnostics in Insert mode (if false,
 ---                           diagnostics are updated on InsertLeave)
 ---       - severity_sort: (default false) Sort diagnostics by severity. This affects the order in
----                         which signs and virtual text are displayed
+---                         which signs and virtual text are displayed. Options:
+---                         * reverse: (boolean) Reverse sort order
 ---@param namespace number|nil Update the options for the given namespace. When omitted, update the
 ---                            global diagnostic options.
 function M.config(opts, namespace)
@@ -989,6 +996,14 @@ function M.show(namespace, bufnr, diagnostics, opts)
     end
   end
 
+  if vim.F.if_nil(opts.severity_sort, false) then
+    if type(opts.severity_sort) == "table" and opts.severity_sort.reverse then
+      table.sort(diagnostics, function(a, b) return a.severity > b.severity end)
+    else
+      table.sort(diagnostics, function(a, b) return a.severity < b.severity end)
+    end
+  end
+
   if opts.underline then
     M._set_underline(namespace, bufnr, diagnostics, opts.underline)
   end

runtime/lua/vim/lsp/diagnostic.lua

@@ -195,10 +195,6 @@ function M.on_publish_diagnostics(_, result, ctx, config)
   local diagnostics = result.diagnostics
 
   if config then
-    if vim.F.if_nil(config.severity_sort, false) then
-      table.sort(diagnostics, function(a, b) return a.severity > b.severity end)
-    end
-
     for _, opt in pairs(config) do
       if type(opt) == 'table' then
         if not opt.severity and opt.severity_limit then

test/functional/lua/diagnostic_spec.lua

@@ -35,7 +35,7 @@ describe('vim.diagnostic', function()
         }
       end
 
-      function make_information(msg, x1, y1, x2, y2)
+      function make_info(msg, x1, y1, x2, y2)
         return {
           lnum = x1,
           col = y1,
@@ -456,7 +456,7 @@ describe('vim.diagnostic', function()
         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_information("Ignored information", 1, 1, 2, 5),
+          make_info("Ignored information", 1, 1, 2, 5),
           make_hint("Here's a hint", 1, 1, 2, 5),
         })
 
@@ -478,7 +478,7 @@ describe('vim.diagnostic', function()
         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_information("Ignored information", 1, 1, 2, 5),
+          make_info("Ignored information", 1, 1, 2, 5),
           make_error("Error On Other Line", 2, 1, 1, 5),
         })
 
@@ -538,6 +538,47 @@ describe('vim.diagnostic', function()
       eq(1, get_extmark_count_with_severity("WARN"))
       eq(1, get_extmark_count_with_severity("HINT"))
     end)
+
+    it('allows sorting by severity', function()
+      local result = exec_lua([[
+        vim.diagnostic.config({
+          underline = true,
+          virtual_text = false,
+          severity_sort = false,
+        })
+
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
+          make_warning('Warning', 4, 4, 4, 4),
+          make_error('Error', 4, 4, 4, 4),
+          make_info('Info', 4, 4, 4, 4),
+        })
+
+        local extmarks = vim.api.nvim_buf_get_extmarks(diagnostic_bufnr, diagnostic_ns, 0, -1, {details = true})
+
+        local warn_highlight = extmarks[1][4].hl_group
+
+        vim.diagnostic.config({
+          severity_sort = true,
+        })
+
+        extmarks = vim.api.nvim_buf_get_extmarks(diagnostic_bufnr, diagnostic_ns, 0, -1, {details = true})
+
+        local err_highlight = extmarks[1][4].hl_group
+
+        vim.diagnostic.config({
+          severity_sort = { reverse = true },
+        })
+
+        extmarks = vim.api.nvim_buf_get_extmarks(diagnostic_bufnr, diagnostic_ns, 0, -1, {details = true})
+
+        local info_highlight = extmarks[1][4].hl_group
+
+        return { warn_highlight, err_highlight, info_highlight }
+      ]])
+      eq('DiagnosticUnderlineWarn', result[1])
+      eq('DiagnosticUnderlineError', result[2])
+      eq('DiagnosticUnderlineInfo', result[3])
+    end)
   end)
 
   describe('set()', function()