Allow custom formatters for b:gitsigns_status

Resolves #15

README.md

@@ -72,6 +72,7 @@ require('gitsigns').setup {
     interval = 1000
   }
   sign_priority = 6,
+  status_formatter = nil, -- Use default
 }
 ```
 
@@ -80,10 +81,9 @@ For information on configuring neovim via lua please see
 
 ## Status Line
 
-Use `b:gitsigns_status` or `b:gitsigns_status_dict`. `b:gitsigns_status` is
-a preformatted and ready to use string (e.g. `+10 -5 ~1`) and ommits zero
-values. `b:gitsigns_status_dict`is a dictionary with the keys `added`,
-`removed`, `changed`.
+Use `b:gitsigns_status` or `b:gitsigns_status_dict`. `b:gitsigns_status` is a
+is formatted using `config.status_formatter`. `b:gitsigns_status_dict`is a
+dictionary with the keys `added`, `removed`, `changed` and `head`.
 
 Example:
 ```viml

doc/gitsigns.txt

@@ -52,7 +52,8 @@ the default settings:
       watch_index = {
         interval = 1000
       },
-      sign_priority = 6
+      sign_priority = 6,
+      status_formatter = nil -- Use default
     }
 <
 
@@ -127,9 +128,9 @@ STATUSLINE                                               *gitsigns-statusline*
 
                                 *b:gitsigns_status* *b:gitsigns_status_dict*
 The buffer variables `b:gitsigns_status` and `b:gitsigns_status_dict` are
-provided. `b:gitsigns_status` is a preformatted and ready to use string (e.g.
-`+10 -5 ~1`) and ommits zero values. `b:gitsigns_status_dict` is a dictionary
-with the keys `added`, `removed`, `changed`.
+provided. `b:gitsigns_status` is formatted using `config.status_formatter`
+. `b:gitsigns_status_dict` is a dictionary with the keys `added`, `removed`,
+`changed` and `head`.
 
 Example:
 >

lua/gitsigns.lua

@@ -404,13 +404,14 @@ local update = debounce_trailing(100, async('update', function(bufnr)
   bcache.diffs = await(run_diff, staged, buftext)
 
   local status, signs = process_diffs(bcache.diffs)
+  status.head = bcache.abbrev_head
 
   await_main()
 
   add_signs(bufnr, signs, true)
 
   set_buf_var(bufnr, 'gitsigns_status_dict', status)
-  set_buf_var(bufnr, 'gitsigns_status', mk_status_txt(status))
+  set_buf_var(bufnr, 'gitsigns_status', config.status_formatter(status))
 
   update_cnt = update_cnt + 1
   dprint(string.format('updates: %s, jobs: %s', update_cnt, job_cnt), bufnr, 'update')
@@ -764,6 +765,10 @@ local function setup(cfg)
 
   config = vim.tbl_deep_extend("keep", cfg or {}, default_config)
 
+  if type(config.status_formatter) ~= 'function' then
+    config.status_formatter = mk_status_txt
+  end
+
   -- Define signs
   for t, sign_name in pairs(sign_map) do
     vim.fn.sign_define(sign_name, {

lua/gitsigns/defaults.lua

@@ -18,10 +18,12 @@ return {
     ['n <leader>hu'] = '<cmd>lua require"gitsigns".undo_stage_hunk()<CR>',
     ['n <leader>hr'] = '<cmd>lua require"gitsigns".reset_hunk()<CR>',
     ['n <leader>hp'] = '<cmd>lua require"gitsigns".preview_hunk()<CR>',
+    ['n m'] = '<cmd>lua require"gitsigns".dump_cache()<CR>',
   },
   watch_index = {
     interval = 1000
   },
   debug_mode = false,
-  sign_priority = 6
+  sign_priority = 6,
+  status_formatter = nil, -- Use default
 }