Calculate folds for buffers with inline diffs.

Author: sindrets

lua/diffview/init.lua

@@ -5,6 +5,7 @@ end
 local hl = require("diffview.hl")
 local lazy = require("diffview.lazy")
 
+local StandardView = lazy.access("diffview.scene.views.standard.standard_view", "StandardView") ---@type StandardView|LazyModule
 local arg_parser = lazy.require("diffview.arg_parser") ---@module "diffview.arg_parser"
 local config = lazy.require("diffview.config") ---@module "diffview.config"
 local lib = lazy.require("diffview.lib") ---@module "diffview.lib"
@@ -75,6 +76,18 @@ function M.init()
       M.emit("refresh_files")
     end,
   })
+  au("User", {
+    group = M.augroup,
+    pattern = "GitSignsUpdate",
+    callback = function()
+      local view = lib.get_current_view()
+
+      if view and view:instanceof(StandardView.__get()) then
+        ---@cast view StandardView
+        view.cur_layout:gs_update_folds()
+      end
+    end,
+  })
 
   -- Set up user autocommand emitters
   DiffviewGlobal.emitter:on("view_opened", function(_)

lua/diffview/scene/layout.lua

@@ -323,5 +323,7 @@ function Layout:sync_scroll()
   end
 end
 
+function Layout:gs_update_folds() end
+
 M.Layout = Layout
 return M

lua/diffview/scene/layouts/diff_1.lua

@@ -2,6 +2,7 @@ local lazy = require("diffview.lazy")
 local Layout = require("diffview.scene.layout").Layout
 local oop = require("diffview.oop")
 
+local GitAdapter = lazy.access("diffview.vcs.adapters.git", "GitAdapter") ---@type GitAdapter|LazyModule
 local Diff3 = lazy.access("diffview.scene.layouts.diff_3", "Diff3") ---@type Diff3|LazyModule
 local Diff4 = lazy.access("diffview.scene.layouts.diff_4", "Diff4") ---@type Diff4|LazyModule
 local File = lazy.access("diffview.vcs.file", "File") ---@type vcs.File|LazyModule
@@ -149,6 +150,12 @@ function Diff1:to_diff4(layout)
   })
 end
 
+function Diff1:gs_update_folds()
+  if self.b:is_file_open() and self.b.file.adapter:instanceof(GitAdapter.__get()) and self.b.file.kind ~= "conflicting" then
+    self.b:gs_update_folds()
+  end
+end
+
 ---FIXME
 ---@override
 ---@param rev Rev

lua/diffview/scene/window.lua

@@ -6,6 +6,7 @@ local File = lazy.access("diffview.vcs.file", "File") ---@type vcs.File|LazyModu
 local GitAdapter = lazy.access("diffview.vcs.adapters.git", "GitAdapter") ---@type GitAdapter|LazyModule
 local RevType = lazy.access("diffview.vcs.rev", "RevType") ---@type RevType|LazyModule
 local config = lazy.require("diffview.config") ---@module "diffview.config"
+local gs_actions = lazy.require("gitsigns.actions") ---@module "gitsigns.actions"
 local lib = lazy.require("diffview.lib") ---@module "diffview.lib"
 local utils = lazy.require("diffview.utils") ---@module "diffview.utils"
 
@@ -64,6 +65,12 @@ function Window:is_focused()
   return self:is_valid() and api.nvim_get_current_win() == self.id
 end
 
+function Window:is_file_open()
+  return self:is_valid()
+      and self.file:is_valid()
+      and api.nvim_win_get_buf(self.id) == self.file.bufnr
+end
+
 ---@param callback fun(file: vcs.File)
 function Window:load_file(callback)
   assert(self.file)
@@ -89,17 +96,23 @@ function Window:open_file(callback)
         self:_save_winopts()
       end
 
+      local winopt_overrides
       local base_rev = utils.tbl_access(self, "parent.parent.revs.a") --[[@as Rev? ]]
+      local use_inline_diff = self.file.kind ~= "conflicting"
+          and self.parent:instanceof(Diff1.__get())
+          and self.file.adapter:instanceof(GitAdapter.__get())
 
-      self:apply_file_winopts()
+      if use_inline_diff then
+        winopt_overrides = { foldmethod = "manual", diff = false }
+      end
+
+      self:apply_file_winopts(winopt_overrides)
       self.file:attach_buffer(false, {
         keymaps = config.get_layout_keymaps(self.parent),
         disable_diagnostics = self.file.kind == "conflicting"
             and config.get_config().view.merge_tool.disable_diagnostics,
         inline_diff = {
-          enable = self.file.kind ~= "conflicting"
-              and self.parent:instanceof(Diff1.__get())
-              and self.file.adapter:instanceof(GitAdapter.__get()),
+          enabled = use_inline_diff,
           base = base_rev and base_rev:object_name(),
         }
       })
@@ -173,10 +186,15 @@ function Window:_restore_winopts()
   end
 end
 
-function Window:apply_file_winopts()
+---@param overrides WindowOptions?
+function Window:apply_file_winopts(overrides)
   assert(self.file)
   if self.file.winopts then
-    utils.set_local(self.id, self.file.winopts)
+    if overrides then
+      utils.set_local(self.id, vim.tbl_extend("force", self.file.winopts, overrides))
+    else
+      utils.set_local(self.id, self.file.winopts)
+    end
   end
 end
 
@@ -194,5 +212,47 @@ function Window:set_file(file)
   self.file = file
 end
 
+function Window:gs_update_folds()
+  if self:is_file_open() and vim.wo[self.id].foldenable then
+    api.nvim_win_call(self.id, function()
+      pcall(vim.cmd, "norm! zE") -- Delete all folds in window
+      local hunks = gs_actions.get_hunks(self.file.bufnr) or {}
+      local context
+
+      for _, v in ipairs(vim.opt.diffopt:get()) do
+        context = tonumber(v:match("^context:(%d+)"))
+        if context then break end
+      end
+
+      context = math.max(1, context or 6)
+
+      local prev_last = -context + 1
+      local lcount = api.nvim_buf_line_count(self.file.bufnr)
+
+      for i = 1, #hunks + 1 do
+        local hunk = hunks[i]
+        local first, last
+
+        if hunk then
+          first = hunk.added.start
+          last = first + hunk.added.count - 1
+        else
+          first = lcount + context
+          last = first
+        end
+
+        -- print(prev_last, first, last, hunk and "hunk" or "nil")
+
+        if first - prev_last > context * 2 + 1 then
+          -- print("FOLD:", prev_last + context, first - context)
+          vim.cmd(("%d,%dfold"):format(prev_last + context, first - context))
+        end
+
+        prev_last = last
+      end
+    end)
+  end
+end
+
 M.Window = Window
 return M

lua/diffview/vcs/file.lua

@@ -11,8 +11,9 @@ local debounce = lazy.require("diffview.debounce") ---@module "diffview.debounce
 
 local pl = lazy.access(utils, "path") ---@type PathLib|LazyModule
 
-local gs_refresh = debounce.debounce_trailing(20, false, vim.schedule_wrap(function()
+local gs_refresh = debounce.debounce_trailing(20, false, vim.schedule_wrap(function(callback)
   gs_actions.refresh()
+  if vim.is_callable(callback) then callback() end
 end))
 
 local api = vim.api
@@ -266,8 +267,9 @@ local function prepare_attach_opt(t1, t2)
     keymaps = {},
     disable_diagnostics = false,
     inline_diff = {
-      enable = false,
+      enabled = false,
       base = nil --[[@as string? ]],
+      update = nil --[[@as function? ]],
     }
   }
 
@@ -318,7 +320,7 @@ function File:attach_buffer(force, opt)
       end
 
       -- Inline diff
-      if state.inline_diff.enable then
+      if state.inline_diff.enabled then
         local gitsigns = require("gitsigns")
         local gs_config = require("gitsigns.config").config
         gitsigns.attach(self.bufnr, {
@@ -331,7 +333,7 @@ function File:attach_buffer(force, opt)
         gs_config.linehl = true
         gs_config.show_deleted = true
         gs_config.word_diff = true
-        gs_refresh()
+        gs_refresh(state.inline_diff.update)
       end
 
       File.attached[self.bufnr] = state
@@ -362,12 +364,12 @@ function File:detach_buffer()
       end
 
       -- Inline diff
-      if state.inline_diff.enable then
+      if state.inline_diff.enabled then
         local gs_config = require("gitsigns.config").config
         gs_config.linehl = false
         gs_config.show_deleted = false
         gs_config.word_diff = false
-        gs_refresh()
+        gs_refresh(state.inline_diff.update)
       end
 
       File.attached[self.bufnr] = nil