Add ability to reset hunks

README.md

@@ -53,6 +53,7 @@ require('gitsigns').setup {
     ['[c']         = '<cmd>lua require("gitsigns").prev_hunk()<CR>',
     ['<leader>hs'] = '<cmd>lua require("gitsigns").stage_hunk()<CR>',
     ['<leader>hu'] = '<cmd>lua require("gitsigns").undo_stage_hunk()<CR>',
+    ['<leader>hr'] = '<cmd>lua require("gitsigns").reset_hunk()<CR>',
     ['<leader>gh'] = '<cmd>lua require("gitsigns").get_hunk()<CR>'
   },
   watch_index = {
@@ -80,6 +81,6 @@ set statusline+=%{get(b:,'gitsigns_status','')}
 ## TODO
 
 - [x] Add action for undoing a stage of a hunk
-- [ ] Add action for undoing a hunk
+- [x] Add action for ~~undoing~~ reseting a hunk
 - [ ] Add action for showing diff (or original text) in a floating window
 - [ ] Add ability to show staged hunks with different signs (maybe in a different sign column?)

lua/gitsigns.lua

@@ -372,16 +372,14 @@ local function create_patch(relpath, hunk, invert)
   if invert then
     ps, pc, ns, nc = ns, nc, ps, pc
 
-    local tlines = {}
-    for _, l in ipairs(lines) do
+    lines = vim.tbl_map(function(l)
       if vim.startswith(l, '+') then
         l = '-'..string.sub(l, 2, -1)
       elseif vim.startswith(l, '-') then
         l = '+'..string.sub(l, 2, -1)
       end
-      table.insert(tlines, l)
-    end
-    lines = tlines
+      return l
+    end, lines)
   end
 
   return {
@@ -424,6 +422,36 @@ local stage_hunk = async(function()
   end
 end)
 
+local reset_hunk = async(function()
+  local bufnr = current_buf()
+  local bcache = cache[bufnr]
+  local hunk = get_hunk(bufnr, bcache.diffs)
+
+  if not hunk then
+    return
+  end
+
+  local orig_lines = vim.tbl_map(function(l)
+      return string.sub(l, 2, -1)
+    end, vim.tbl_filter(function(l)
+      return vim.startswith(l, '-')
+    end, hunk.lines))
+
+  local lstart, lend
+  if hunk.type == 'delete' then
+      lstart = hunk.start
+      lend = hunk.start
+  else
+    local length = vim.tbl_count(vim.tbl_filter(function(l)
+      return vim.startswith(l, '+')
+    end, hunk.lines))
+
+    lstart = hunk.start - 1
+    lend = hunk.start - 1 + length
+  end
+  api.nvim_buf_set_lines(bufnr, lstart, lend, false, orig_lines)
+end)
+
 local undo_stage_hunk = async(function()
   local bufnr = current_buf()
   local bcache = cache[bufnr]
@@ -549,6 +577,7 @@ return {
   get_hunk   = get_hunk,
   stage_hunk = stage_hunk,
   undo_stage_hunk = undo_stage_hunk,
+  reset_hunk = reset_hunk,
   next_hunk  = next_hunk,
   prev_hunk  = prev_hunk,
   attach     = attach,

lua/gitsigns/defaults.lua

@@ -11,6 +11,7 @@ return {
     ['[c']         = '<cmd>lua require"gitsigns".prev_hunk()<CR>',
     ['<leader>hs'] = '<cmd>lua require"gitsigns".stage_hunk()<CR>',
     ['<leader>hu'] = '<cmd>lua require"gitsigns".undo_stage_hunk()<CR>',
+    ['<leader>hr'] = '<cmd>lua require"gitsigns".reset_hunk()<CR>',
     ['<leader>gh'] = '<cmd>lua require"gitsigns".get_hunk()<CR>'
   },
   watch_index = {