feat(lsp.util): refactor get_border_size()

runtime/lua/vim/lsp/util.lua

@@ -21,85 +21,73 @@ local default_border = {
   { ' ', 'NormalFloat' },
 }
 
+--- @param border string|(string|[string,string])[]
+local function border_error(border)
+  error(
+    string.format(
+      'invalid floating preview border: %s. :help vim.api.nvim_open_win()',
+      vim.inspect(border)
+    ),
+    2
+  )
+end
+
+local border_size = {
+  none = { 0, 0 },
+  single = { 2, 2 },
+  double = { 2, 2 },
+  rounded = { 2, 2 },
+  solid = { 2, 2 },
+  shadow = { 1, 1 },
+}
+
 --- Check the border given by opts or the default border for the additional
 --- size it adds to a float.
----@param opts? {border:string|(string|[string,string])[]}
----@return {height:integer,width:integer} # size of border in the form of { height = height, width = width }
+--- @param opts? {border:string|(string|[string,string])[]}
+--- @return integer height
+--- @return integer width
 local function get_border_size(opts)
   local border = opts and opts.border or default_border
-  local height = 0
-  local width = 0
 
   if type(border) == 'string' then
-    local border_size = {
-      none = { 0, 0 },
-      single = { 2, 2 },
-      double = { 2, 2 },
-      rounded = { 2, 2 },
-      solid = { 2, 2 },
-      shadow = { 1, 1 },
-    }
-    if border_size[border] == nil then
-      error(
-        string.format(
-          'invalid floating preview border: %s. :help vim.api.nvim_open_win()',
-          vim.inspect(border)
-        )
-      )
+    if not border_size[border] then
+      border_error(border)
     end
-    height, width = unpack(border_size[border])
-  else
-    if 8 % #border ~= 0 then
-      error(
-        string.format(
-          'invalid floating preview border: %s. :help vim.api.nvim_open_win()',
-          vim.inspect(border)
-        )
-      )
-    end
-    --- @param id integer
-    local function border_width(id)
-      id = (id - 1) % #border + 1
-      local e = border[id]
-      if type(e) == 'table' then
-        -- border specified as a table of <character, highlight group>
-        return vim.fn.strdisplaywidth(e[1])
-      elseif type(e) == 'string' then
-        -- border specified as a list of border characters
-        return vim.fn.strdisplaywidth(e)
-      end
-      error(
-        string.format(
-          'invalid floating preview border: %s. :help vim.api.nvim_open_win()',
-          vim.inspect(border)
-        )
-      )
-    end
-    --- @param id integer
-    local function border_height(id)
-      id = (id - 1) % #border + 1
-      local e = border[id]
-      if type(e) == 'table' then
-        -- border specified as a table of <character, highlight group>
-        return #e[1] > 0 and 1 or 0
-      elseif type(e) == 'string' then
-        -- border specified as a list of border characters
-        return #e > 0 and 1 or 0
-      end
-      error(
-        string.format(
-          'invalid floating preview border: %s. :help vim.api.nvim_open_win()',
-          vim.inspect(border)
-        )
-      )
-    end
-    height = height + border_height(2) -- top
-    height = height + border_height(6) -- bottom
-    width = width + border_width(4) -- right
-    width = width + border_width(8) -- left
+    return unpack(border_size[border])
   end
 
-  return { height = height, width = width }
+  if 8 % #border ~= 0 then
+    border_error(border)
+  end
+
+  --- @param id integer
+  --- @return string
+  local function elem(id)
+    id = (id - 1) % #border + 1
+    local e = border[id]
+    if type(e) == 'table' then
+      -- border specified as a table of <character, highlight group>
+      return e[1]
+    elseif type(e) == 'string' then
+      -- border specified as a list of border characters
+      return e
+    end
+    --- @diagnostic disable-next-line:missing-return
+    border_error(border)
+  end
+
+  --- @param e string
+  local function border_height(e)
+    return #e > 0 and 1 or 0
+  end
+
+  local top, bottom = elem(2), elem(6)
+  local height = border_height(top) + border_height(bottom)
+
+  local right, left = elem(4), elem(8)
+  local width = vim.fn.strdisplaywidth(right) + vim.fn.strdisplaywidth(left)
+
+  return height, width
 end
 
 --- Splits string at newlines, optionally removing unwanted blank lines.
@@ -930,7 +918,7 @@ function M.make_floating_popup_options(width, height, opts)
     anchor_below = lines_below > lines_above
   end
 
-  local border_height = get_border_size(opts).height
+  local border_height = get_border_size(opts)
   local row, col --- @type integer?, integer?
   if anchor_below then
     anchor = anchor .. 'N'
@@ -1495,7 +1483,7 @@ function M._make_floating_popup_size(contents, opts)
     end
   end
 
-  local border_width = get_border_size(opts).width
+  local _, border_width = get_border_size(opts)
   local screen_width = api.nvim_win_get_width(0)
   width = math.min(width, screen_width)