refactor(git): unify diff/object dispatch, codify naming, add :Gdiffsplit

lua/git/sidebar.lua

@@ -1,5 +1,5 @@
 local diff = require("git.diff")
-local git = require("git")
+local object = require("git.object")
 local repo = require("git.repo")
 local util = require("git.util")
 
@@ -433,7 +433,7 @@ local function refresh(bufnr, prefetched_stdout)
         end
         -- Any fs-event that triggered this refresh might have changed the
         -- worktree under the diff buffers we last opened; invalidate the
-        -- cache so the next show_diff recomputes panes.
+        -- cache so the next view_entry recomputes panes.
         s.last_shown_key = nil
         local fp = fingerprint(branch, groups)
         if fp == s.last_render_key then
@@ -484,18 +484,23 @@ end
 ---@return ow.Git.DiffSide
 local function head_pane(worktree, path)
     return {
-        buf = diff.git_show_buf(worktree, "HEAD:" .. path),
+        buf = object.buf_for(worktree, "HEAD:" .. path),
         name = "git://HEAD:" .. path,
     }
 end
 
 ---@param worktree string
 ---@param path string
+---@param kind "index"|"HEAD"|"worktree"
 ---@return ow.Git.DiffSide
-local function absent_pane(worktree, path)
+local function absent_pane(worktree, path, kind)
     return {
         buf = diff.empty_buf(),
-        name = "[absent] " .. vim.fs.joinpath(worktree, path),
+        name = string.format(
+            "[absent %s] %s",
+            kind,
+            vim.fs.joinpath(worktree, path)
+        ),
     }
 end
 
@@ -503,10 +508,9 @@ end
 ---@param path string
 ---@return ow.Git.DiffSide
 local function worktree_pane(worktree, path)
-    return {
-        buf = diff.load_file_buf(vim.fs.joinpath(worktree, path)),
-        name = nil,
-    }
+    local buf = vim.fn.bufadd(vim.fs.joinpath(worktree, path))
+    vim.fn.bufload(buf)
+    return { buf = buf, name = nil }
 end
 
 ---@param s ow.Git.SidebarState
@@ -518,11 +522,11 @@ local function index_pane(s, entry)
         or (entry.section == "Staged" and entry.x == "D")
     )
     if not in_index then
-        return absent_pane(s.worktree, entry.path)
+        return absent_pane(s.worktree, entry.path, "index")
     end
     return {
-        buf = diff.git_show_buf(s.worktree, ":" .. entry.path),
-        name = "git://:" .. entry.path,
+        buf = object.buf_for(s.worktree, ":0:" .. entry.path),
+        name = "git://:0:" .. entry.path,
     }
 end
 
@@ -534,7 +538,7 @@ local function other_pane(s, entry)
     local worktree = s.worktree
     if entry.section == "Staged" then
         if entry.x == "A" then
-            return absent_pane(worktree, p)
+            return absent_pane(worktree, p, "HEAD")
         end
         if entry.x == "D" then
             return head_pane(worktree, p)
@@ -544,7 +548,7 @@ local function other_pane(s, entry)
     end
     if entry.section == "Unstaged" then
         if entry.y == "D" then
-            return absent_pane(worktree, p)
+            return absent_pane(worktree, p, "worktree")
         end
         return worktree_pane(worktree, p)
     end
@@ -649,7 +653,7 @@ end
 ---@param s ow.Git.SidebarState
 ---@param entry ow.Git.SidebarEntry
 ---@param focus_left boolean
-local function show_diff(s, entry, focus_left)
+local function view_entry(s, entry, focus_left)
     if not entry.path then
         return
     end
@@ -713,22 +717,7 @@ local function show_diff(s, entry, focus_left)
     s.diff_left_win = left_win
     s.diff_right_win = right_win
 
-    -- Toggle diff off around the buffer swap so Vim tears down the old
-    -- diff group and re-establishes a fresh one against the new pair.
-    -- nvim_win_set_buf swaps the buffer pointer without invalidating
-    -- cached diff state, and :diffupdate alone doesn't reliably force a
-    -- recompute when no buffer contents have actually changed.
-    diff.set_diff(left_win, false)
-    diff.set_diff(right_win, false)
-    vim.api.nvim_win_set_buf(left_win, pair.left.buf)
-    vim.api.nvim_win_set_buf(right_win, pair.right.buf)
-    for _, side in ipairs({ pair.left, pair.right }) do
-        if side.name then
-            diff.set_buf_name_and_filetype(side.buf, side.name)
-        end
-    end
-    diff.set_diff(left_win, true)
-    diff.set_diff(right_win, true)
+    diff.update_pair(left_win, right_win, pair)
     s.last_shown_key = key
 
     if focus_left then
@@ -744,7 +733,7 @@ local function preview_or_open(focus_left)
     if not s or not entry then
         return
     end
-    show_diff(s, entry, focus_left)
+    view_entry(s, entry, focus_left)
 end
 
 local function action_stage()
@@ -876,7 +865,7 @@ local function open(worktree)
     end
 
     local previous_win = vim.api.nvim_get_current_win()
-    local bufnr, win = git.new_scratch({ split = "left", bufhidden = "wipe" })
+    local bufnr, win = util.new_scratch({ split = "left", bufhidden = "wipe" })
     vim.bo[bufnr].filetype = "gitsidebar"
 
     vim.wo[win].number = false