Merge pull request #1599 from kjughx/revert-hunk

Add ability to revert hunk

lua/neogit/buffers/commit_view/init.lua

@@ -290,7 +290,7 @@ function M:open(kind)
         end),
         [popups.mapping_for("RemotePopup")] = popups.open("remote"),
         [popups.mapping_for("RevertPopup")] = popups.open("revert", function(p)
-          p { commits = { self.commit_info.oid } }
+          p { commits = { self.commit_info.oid }, item = self.buffer.ui:get_hunk_or_filename_under_cursor() }
         end),
         [popups.mapping_for("ResetPopup")] = popups.open("reset", function(p)
           p { commit = self.commit_info.oid }

lua/neogit/buffers/status/actions.lua

@@ -120,7 +120,8 @@ M.v_discard = function(self)
             for _, hunk in ipairs(hunks) do
               table.insert(invalidated_diffs, "*:" .. item.name)
               table.insert(patches, function()
-                local patch = git.index.generate_patch(item, hunk, hunk.from, hunk.to, true)
+                local patch =
+                  git.index.generate_patch(hunk, { from = hunk.from, to = hunk.to, reverse = true })
 
                 logger.debug(("Discarding Patch: %s"):format(patch))
 
@@ -231,7 +232,7 @@ M.v_stage = function(self)
 
           if #hunks > 0 then
             for _, hunk in ipairs(hunks) do
-              table.insert(patches, git.index.generate_patch(item, hunk, hunk.from, hunk.to))
+              table.insert(patches, git.index.generate_patch(hunk.hunk, { from = hunk.from, to = hunk.to }))
             end
           else
             if section.name == "unstaged" then
@@ -281,7 +282,10 @@ M.v_unstage = function(self)
 
           if #hunks > 0 then
             for _, hunk in ipairs(hunks) do
-              table.insert(patches, git.index.generate_patch(item, hunk, hunk.from, hunk.to, true))
+              table.insert(
+                patches,
+                git.index.generate_patch(hunk, { from = hunk.from, to = hunk.to, reverse = true })
+              )
             end
           else
             table.insert(files, item.escaped_path)
@@ -781,17 +785,16 @@ M.n_discard = function(self)
       local hunk =
         self.buffer.ui:item_hunks(selection.item, selection.first_line, selection.last_line, false)[1]
 
-      local patch = git.index.generate_patch(selection.item, hunk, hunk.from, hunk.to, true)
+      local patch = git.index.generate_patch(hunk, { from = hunk.from, to = hunk.to, reverse = true })
 
       if section == "untracked" then
         message = "Discard hunk?"
         action = function()
           local hunks =
             self.buffer.ui:item_hunks(selection.item, selection.first_line, selection.last_line, false)
 
-          local patch = git.index.generate_patch(selection.item, hunks[1], hunks[1].from, hunks[1].to, true)
-
-          git.index.apply(patch, { reverse = true })
+          local patch =
+            git.index.generate_patch(hunks[1], { from = hunks[1].from, to = hunks[1].to, reverse = true })
           git.index.apply(patch, { reverse = true })
         end
         refresh = { update_diffs = { "untracked:" .. selection.item.name } }
@@ -1057,7 +1060,7 @@ M.n_stage = function(self)
         local item = self.buffer.ui:get_item_under_cursor()
         assert(item, "Item cannot be nil")
 
-        local patch = git.index.generate_patch(item, stagable.hunk, stagable.hunk.from, stagable.hunk.to)
+        local patch = git.index.generate_patch(stagable.hunk)
         git.index.apply(patch, { cached = true })
         self:dispatch_refresh({ update_diffs = { "*:" .. item.escaped_path } }, "n_stage")
       elseif stagable.filename then
@@ -1131,8 +1134,10 @@ M.n_unstage = function(self)
       if unstagable.hunk then
         local item = self.buffer.ui:get_item_under_cursor()
         assert(item, "Item cannot be nil")
-        local patch =
-          git.index.generate_patch(item, unstagable.hunk, unstagable.hunk.from, unstagable.hunk.to, true)
+        local patch = git.index.generate_patch(
+          unstagable.hunk,
+          { from = unstagable.hunk.from, to = unstagable.hunk.to, reverse = true }
+        )
 
         git.index.apply(patch, { cached = true, reverse = true })
         self:dispatch_refresh({ update_diffs = { "*:" .. item.escaped_path } }, "n_unstage")

lua/neogit/lib/git/diff.lua

@@ -24,12 +24,14 @@ local sha256 = vim.fn.sha256
 ---@field deletions number
 ---
 ---@class Hunk
+---@field file string
 ---@field index_from number
 ---@field index_len number
 ---@field diff_from number
 ---@field diff_to number
 ---@field first number First line number in buffer
 ---@field last number Last line number in buffer
+---@field lines string[]
 ---
 ---@class DiffStagedStats
 ---@field summary string
@@ -224,6 +226,11 @@ local function parse_diff(raw_diff, raw_stats)
   local file = build_file(header, kind)
   local stats = parse_diff_stats(raw_stats or {})
 
+  util.map(hunks, function(hunk)
+    hunk.file = file
+    return hunk
+  end)
+
   return { ---@type Diff
     kind = kind,
     lines = lines,

lua/neogit/lib/git/index.lua

@@ -6,19 +6,15 @@ local util = require("neogit.lib.util")
 local M = {}
 
 ---Generates a patch that can be applied to index
----@param item any
 ---@param hunk Hunk
----@param from number
----@param to number
----@param reverse boolean|nil
+---@param opts table|nil
 ---@return string
-function M.generate_patch(item, hunk, from, to, reverse)
-  reverse = reverse or false
+function M.generate_patch(hunk, opts)
+  opts = opts or { reverse = false, cached = false, index = false }
+  local reverse = opts.reverse
 
-  if not from and not to then
-    from = hunk.diff_from + 1
-    to = hunk.diff_to
-  end
+  local from = opts.from or 1
+  local to = opts.to or (hunk.diff_to - hunk.diff_from)
 
   assert(from <= to, string.format("from must be less than or equal to to %d %d", from, to))
   if from > to then
@@ -29,35 +25,31 @@ function M.generate_patch(item, hunk, from, to, reverse)
   local len_start = hunk.index_len
   local len_offset = 0
 
-  -- + 1 skips the hunk header, since we construct that manually afterwards
-  -- TODO: could use `hunk.lines` instead if this is only called with the `SelectedHunk` type
-  for k = hunk.diff_from + 1, hunk.diff_to do
-    local v = item.diff.lines[k]
-    local operand, line = v:match("^([+ -])(.*)")
-
+  for k, line in pairs(hunk.lines) do
+    local operand, l = line:match("^([+ -])(.*)")
     if operand == "+" or operand == "-" then
       if from <= k and k <= to then
         len_offset = len_offset + (operand == "+" and 1 or -1)
-        table.insert(diff_content, v)
+        table.insert(diff_content, line)
       else
         -- If we want to apply the patch normally, we need to include every `-` line we skip as a normal line,
         -- since we want to keep that line.
         if not reverse then
           if operand == "-" then
-            table.insert(diff_content, " " .. line)
+            table.insert(diff_content, " " .. l)
           end
           -- If we want to apply the patch in reverse, we need to include every `+` line we skip as a normal line, since
           -- it's unchanged as far as the diff is concerned and should not be reversed.
           -- We also need to adapt the original line offset based on if we skip or not
         elseif reverse then
           if operand == "+" then
-            table.insert(diff_content, " " .. line)
+            table.insert(diff_content, " " .. l)
           end
           len_start = len_start + (operand == "-" and -1 or 1)
         end
       end
     else
-      table.insert(diff_content, v)
+      table.insert(diff_content, line)
     end
   end
 
@@ -68,9 +60,7 @@ function M.generate_patch(item, hunk, from, to, reverse)
   )
 
   local worktree_root = git.repo.worktree_root
-
-  assert(item.absolute_path, "Item is not a path")
-  local path = Path:new(item.absolute_path):make_relative(worktree_root)
+  local path = Path:new(hunk.file):make_relative(worktree_root)
 
   table.insert(diff_content, 1, string.format("+++ b/%s", path))
   table.insert(diff_content, 1, string.format("--- a/%s", path))

lua/neogit/lib/git/revert.lua

@@ -16,6 +16,11 @@ function M.commits(commits, args)
   end
 end
 
+function M.hunk(hunk, _)
+  local patch = git.index.generate_patch(hunk, { reverse = true })
+  git.index.apply(patch, { reverse = true })
+end
+
 function M.continue()
   git.cli.revert.continue.call()
 end

lua/neogit/lib/ui/init.lua

@@ -182,25 +182,19 @@ function Ui:item_hunks(item, first_line, last_line, partial)
 
   if not item.folded and item.diff.hunks then
     for _, h in ipairs(item.diff.hunks) do
-      if h.first <= last_line and h.last >= first_line then
+      if h.first <= first_line and h.last >= last_line then
         local from, to
 
         if partial then
-          local cursor_offset = first_line - h.first
           local length = last_line - first_line
 
-          from = h.diff_from + cursor_offset
+          from = first_line - h.first
           to = from + length
         else
           from = h.diff_from + 1
           to = h.diff_to
         end
 
-        local hunk_lines = {}
-        for i = from, to do
-          table.insert(hunk_lines, item.diff.lines[i])
-        end
-
         -- local conflict = false
         -- for _, n in ipairs(conflict_markers) do
         --   if from <= n and n <= to then
@@ -214,7 +208,6 @@ function Ui:item_hunks(item, first_line, last_line, partial)
           to = to,
           __index = h,
           hunk = h,
-          lines = hunk_lines,
           -- conflict = conflict,
         }
 

lua/neogit/popups/revert/actions.lua

@@ -70,6 +70,10 @@ function M.changes(popup)
   end
 end
 
+function M.hunk(popup)
+  git.revert.hunk(popup.state.env.item.hunk, popup:get_arguments())
+end
+
 function M.continue()
   git.revert.continue()
 end

lua/neogit/popups/revert/init.lua

@@ -23,6 +23,7 @@ function M.create(env)
     :group_heading("Revert")
     :action_if(not in_progress, "v", "Commit(s)", actions.commits)
     :action_if(not in_progress, "V", "Changes", actions.changes)
+    :action_if(((not in_progress) and env.item ~= nil), "h", "Hunk", actions.hunk)
     :action_if(in_progress, "v", "continue", actions.continue)
     :action_if(in_progress, "s", "skip", actions.skip)
     :action_if(in_progress, "a", "abort", actions.abort)

tests/specs/neogit/lib/git/index_spec.lua

@@ -10,17 +10,15 @@ local function run_with_hunk(hunk, from, to, reverse)
   local header_matches =
     vim.fn.matchlist(lines[1], "@@ -\\(\\d\\+\\),\\(\\d\\+\\) +\\(\\d\\+\\),\\(\\d\\+\\) @@")
   return generate_patch_from_selection({
-    name = "test.txt",
-    absolute_path = "test.txt",
-    diff = { lines = lines },
-  }, {
     first = 1,
     last = #lines,
     index_from = header_matches[2],
     index_len = header_matches[3],
     diff_from = diff_from,
     diff_to = #lines,
-  }, diff_from + from, diff_from + to, reverse)
+    lines = vim.list_slice(lines, 2),
+    file = "test.txt",
+  }, { from = from, to = to, reverse = reverse })
 end
 
 describe("patch creation", function()

tests/specs/neogit/lib/git/log_spec.lua

@@ -96,6 +96,7 @@ describe("lib.git.log.parse", function()
               index_from = 692,
               index_len = 33,
               length = 40,
+              file = "lua/neogit/status.lua",
               line = "@@ -692,33 +692,28 @@ end",
               lines = {
                 " ---@param first_line number",
@@ -149,6 +150,7 @@ describe("lib.git.log.parse", function()
               index_from = 734,
               index_len = 14,
               length = 15,
+              file = "lua/neogit/status.lua",
               line = "@@ -734,14 +729,10 @@ function M.get_item_hunks(item, first_line, last_line, partial)",
               lines = {
                 "       setmetatable(o, o)",
@@ -290,6 +292,7 @@ describe("lib.git.log.parse", function()
               index_len = 7,
               length = 9,
               line = "@@ -1,7 +1,9 @@",
+              file = "LICENSE",
               lines = {
                 " MIT License",
                 " ",