feat(ui): add show_modified option

doc/bufferline.txt

@@ -164,7 +164,8 @@ The available configuration are:
             sort_by = 'insert_after_current' |'insert_at_end' | 'id' | 'extension' | 'relative_directory' | 'directory' | 'tabs' | function(buffer_a, buffer_b)
                 -- add custom logic
                 return buffer_a.modified > buffer_b.modified
-            end
+            end,
+            show_modified = true | false | function(context): boolean
         }
     }
 <

lua/bufferline/config.lua

@@ -651,6 +651,7 @@ local function get_defaults()
     groups = { items = {}, options = { toggle_hidden_on_enter = true } },
     hover = { enabled = false, reveal = {}, delay = 200 },
     debug = { logging = false },
+    show_modified = true,
   }
   return { options = opts, highlights = derive_colors(opts.style_preset) }
 end

lua/bufferline/ui.lua

@@ -313,6 +313,19 @@ local function add_icon(context)
   end
 end
 
+--- Determine if the modified icon should be shown for the current element.
+--- @param context bufferline.RenderContext
+--- @return boolean
+local function show_modified(context)
+  local show = config.options.show_modified
+  if type(show) == "boolean" then
+    return show
+  elseif type(show) == "function" then
+    return show(context)
+  end
+  return false
+end
+
 --- The suffix can be either the modified icon, space to replace the icon if
 --- a user has turned them off or the close icon if the element is not currently modified
 --- @param context bufferline.RenderContext
@@ -329,7 +342,7 @@ local function add_suffix(context)
     highlight = element.modified and hl.modified or nil,
   }
   local close = get_close_icon(element.id, context)
-  return not element.modified and close or modified
+  return not (show_modified(context) and element.modified) and close or modified
 end
 
 --- TODO: We increment the buffer length by the separator although the final

tests/ui_spec.lua

@@ -69,6 +69,33 @@ describe("UI Tests", function()
       })
       assert.is_equal(segment.text, "a_very_very_very_…")
     end)
+
+    it("should render an icon if show_modified is true", function()
+      config.setup({ options = { show_modified = true } })
+      config.apply()
+      local buf = MockBuffer:new({ id = 1, name = "file.txt", length = 10, modified = true })
+      local el = ui.element({}, buf)
+      local segment = ui.to_tabline_str(el:component(1))
+      assert.is_truthy(segment:match(config.options.modified_icon))
+    end)
+
+    it("should not render an icon if show_modified is false", function()
+      config.setup({ options = { show_modified = false } })
+      config.apply()
+      local buf = MockBuffer:new({ id = 1, name = "file.txt", length = 10, modified = true })
+      local el = ui.element({}, buf)
+      local segment = ui.to_tabline_str(el:component(1))
+      assert.is_falsy(segment:match(config.options.modified_icon))
+    end)
+
+    it("should render an icon if show_modified is a function", function()
+      config.setup({ options = { show_modified = function(context) return true end } })
+      config.apply()
+      local buf = MockBuffer:new({ id = 1, name = "file.txt", length = 10, modified = true })
+      local el = ui.element({}, buf)
+      local segment = ui.to_tabline_str(el:component(1))
+      assert.is_truthy(segment:match(config.options.modified_icon))
+    end)
   end)
 
   describe("Hover events - ", function()