Add support for gina.vim and vim-signify (#2)

* add support for gina.vim

* add support for vim-signify

* fix wrong value in vim-signify empty buffer

* add missing single quotes

* fix table indexing mistake

* add parentheses to make it work

lua/hardline/parts/git.lua

@@ -2,8 +2,21 @@ local fn = vim.fn
 local g = vim.g
 
 local function get_hunks()
-  if not g.loaded_gitgutter then return '' end
-  local summary = fn.GitGutterGetHunkSummary()
+  local summary
+  if g.loaded_gitgutter then
+    summary = fn.GitGutterGetHunkSummary()
+  elseif g.loaded_signify then
+    summary = fn['sy#repo#get_stats']()
+    -- signify return [-1,-1,-1] in empty buffer
+    -- that is why we check if one of value is -1
+    -- then stop the operation by return empty string
+    if (summary[1] == -1) then
+      return ''
+    end
+  else
+    -- return empty string if none of them is loaded
+    return ''
+  end
   return table.concat({
     string.format('+%d', summary[1]),
     string.format('~%d', summary[2]),
@@ -12,8 +25,12 @@ local function get_hunks()
 end
 
 local function get_branch()
-  if not g.loaded_fugitive then return false end
-  local branch = fn.FugitiveHead()
+  local branch
+  if g.loaded_fugitive then
+    branch = fn.FugitiveHead()
+  elseif g.loaded_gina then
+    branch = fn['gina#component#repo#branch']()
+  end
   return branch ~= '' and string.format('(%s)', branch) or ''
 end