fix(statusline)!: make section_diagnostics() depend only on diagnostic

Details:
- Depend only on if there are actually present diagnostic entries.
  This allows showing in not normal buffers and if there is no LSP
  server attached.
  Do not show ' -' if there is no diagnostics, as this will be
  **always** shown, which is not needed.
- Use "Diag" fallback icon instead of "LSP".

Resolve #687

CHANGELOG.md

@@ -52,6 +52,10 @@
 
 ## mini.statusline
 
+- BREAKING: `section_diagnostics()` now depends only on defined diagnostic. This means:
+    - Something is shown **only** if there is any diagnostic actually present in the buffer. No diagnostic entries - nothing is shown.
+    Previously it did not show if there was no LSP servers attached (as initially diagnostics came only from LSP) or buffer was not normal.
+    - Fallback icon is "Diag" instead of "LSP".
 - BREAKING FEATURE: `section_git()` now prefers using data from 'mini.git' with fallback on pure HEAD data from 'lewis6991/gistigns.nvim'.
 - FEATURE: add `section_diff()` to show data from 'mini.diff' with fallback on diff data from 'lewis6991/gistigns.nvim'.
 - BREAKING FEATURE: update default active content to use both `section_git()` and `section_diff()`.

doc/mini-statusline.txt

@@ -259,8 +259,8 @@ Return ~
                   `MiniStatusline.section_diagnostics`({args})
 Section for Neovim's builtin diagnostics
 
-Shows nothing if there is no attached LSP clients or for short output.
-Otherwise uses builtin Neovim capabilities to compute and show number of
+Shows nothing if diagnostics is disabled, no diagnostic is set, or for short
+output. Otherwise uses |vim.diagnostic.get()| to compute and show number of
 errors ('E'), warnings ('W'), information ('I'), and hints ('H').
 
 Short output is returned if window width is lower than `args.trunc_width`.

lua/mini/statusline.lua

@@ -308,8 +308,8 @@ end
 
 --- Section for Neovim's builtin diagnostics
 ---
---- Shows nothing if there is no attached LSP clients or for short output.
---- Otherwise uses builtin Neovim capabilities to compute and show number of
+--- Shows nothing if diagnostics is disabled, no diagnostic is set, or for short
+--- output. Otherwise uses |vim.diagnostic.get()| to compute and show number of
 --- errors ('E'), warnings ('W'), information ('I'), and hints ('H').
 ---
 --- Short output is returned if window width is lower than `args.trunc_width`.
@@ -318,8 +318,7 @@ end
 ---
 ---@return __statusline_section
 MiniStatusline.section_diagnostics = function(args)
-  local dont_show = MiniStatusline.is_truncated(args.trunc_width) or H.isnt_normal_buffer() or H.has_no_lsp_attached()
-  if dont_show or H.diagnostic_is_disabled() then return '' end
+  if MiniStatusline.is_truncated(args.trunc_width) or H.diagnostic_is_disabled() then return '' end
 
   -- Construct string parts
   local count = H.diagnostic_get_count()
@@ -329,11 +328,11 @@ MiniStatusline.section_diagnostics = function(args)
     -- Add level info only if diagnostic is present
     if n > 0 then table.insert(t, ' ' .. level.sign .. n) end
   end
+  if #t == 0 then return '' end
 
   local use_icons = H.use_icons or H.get_config().use_icons
-  local icon = args.icon or (use_icons and '' or 'LSP')
-  if vim.tbl_count(t) == 0 then return ('%s -'):format(icon) end
-  return string.format('%s%s', icon, table.concat(t, ''))
+  local icon = args.icon or (use_icons and '' or 'Diag')
+  return icon .. table.concat(t, '')
 end
 
 --- Section for file name
@@ -370,9 +369,8 @@ end
 MiniStatusline.section_fileinfo = function(args)
   local filetype = vim.bo.filetype
 
-  -- Don't show anything if can't detect file type or not inside a "normal
-  -- buffer"
-  if (filetype == '') or H.isnt_normal_buffer() then return '' end
+  -- Don't show anything if no filetype or not inside a "normal buffer"
+  if filetype == '' or vim.bo.buftype ~= '' then return '' end
 
   -- Add filetype icon
   H.ensure_get_icon()
@@ -604,11 +602,6 @@ end
 H.default_content_inactive = function() return '%#MiniStatuslineInactive#%F%=' end
 
 -- Utilities ------------------------------------------------------------------
-H.isnt_normal_buffer = function()
-  -- For more information see ":h buftype"
-  return vim.bo.buftype ~= ''
-end
-
 H.get_filesize = function()
   local size = vim.fn.getfsize(vim.fn.getreg('%'))
   if size < 1024 then

tests/test_statusline.lua

@@ -307,15 +307,14 @@ T['section_diagnostics()'] = new_set({ hooks = { pre_case = mock_diagnostics } }
 T['section_diagnostics()']['works'] = function()
   eq(child.lua_get('MiniStatusline.section_diagnostics({})'), ' E4 W3 I2 H1')
 
-  -- Should return predefined string if no diagnostic output
-  child.lua('vim.diagnostic.get = function(...) return {} end')
-  child.lua('vim.diagnostic.count = function(...) return {} end')
-  child.lua('vim.diagnostic.get = function(...) return {} end')
-  eq(child.lua_get('MiniStatusline.section_diagnostics({})'), ' -')
-
-  -- Should return empty string if no LSP client attached
+  -- Should not depend on LSP server attached
   child.lua('vim.lsp.buf_get_clients = function() return {} end')
   if child.fn.has('nvim-0.8') == 1 then child.lua('_G.detach_lsp()') end
+  eq(child.lua_get('MiniStatusline.section_diagnostics({})'), ' E4 W3 I2 H1')
+
+  -- Should return empty string if no diagnostic entries defined
+  child.lua('vim.diagnostic.get = function(...) return {} end')
+  child.lua('vim.diagnostic.count = function(...) return {} end')
   eq(child.lua_get('MiniStatusline.section_diagnostics({})'), '')
 end
 
@@ -333,15 +332,20 @@ end
 
 T['section_diagnostics()']['respects `config.use_icons`'] = function()
   child.lua('MiniStatusline.config.use_icons = false')
-  eq(child.lua_get([[MiniStatusline.section_diagnostics({})]]), 'LSP E4 W3 I2 H1')
+  eq(child.lua_get([[MiniStatusline.section_diagnostics({})]]), 'Diag E4 W3 I2 H1')
 
   -- Should also use buffer local config
   child.b.ministatusline_config = { use_icons = true }
   eq(child.lua_get([[MiniStatusline.section_diagnostics({})]]), ' E4 W3 I2 H1')
 end
 
-T['section_diagnostics()']['is shown only in normal buffers'] = function()
+T['section_diagnostics()']['works in not normal buffers'] = function()
+  -- Should return empty string if there is no diagnostic defined
   child.cmd('help')
+  eq(child.lua_get('MiniStatusline.section_diagnostics({})'), ' E4 W3 I2 H1')
+
+  child.lua('vim.diagnostic.get = function(...) return {} end')
+  child.lua('vim.diagnostic.count = function(...) return {} end')
   eq(child.lua_get('MiniStatusline.section_diagnostics({})'), '')
 end