fix(inline): render extmarks before the buffer becomes visible

[dlyongemallo]

Fixes #172.

[Copilot]

Pull request overview

This PR addresses an inline diff regression where the “b” buffer could become visible before inline-diff extmarks were rendered, causing a first redraw without highlights. It introduces a prerender step to lay down extmarks before open_files swaps the window buffer, and extends full_width deletion padding computation to accept a window hint when the buffer isn’t displayed yet.

Changes:

• Add Diff1Inline:_prerender() and rework create/use_entry/create_post to render extmarks before open_files displays the buffer, while scoping the inline namespace to prevent window leakage.
• Add opts.winid support to inline_diff.render() so full_width padding can be computed against an “eventual” target window.
• Add functional regression tests covering prerender behavior, namespace scoping, and hinted full_width padding.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
lua/diffview/scene/layouts/diff_1_inline.lua	Adds _prerender, refactors render flow to avoid first-draw highlight gaps, and adds a create_post override for scoping + full_width follow-up repaint.
lua/diffview/scene/inline_diff.lua	Enhances full_width padding target calculation to consider an optional winid hint.
lua/diffview/tests/functional/layouts_spec.lua	Adds regression tests for prerendering, nulled/binary behavior, scoping, and create_post repaint gating.
lua/diffview/tests/functional/inline_diff_spec.lua	Adds tests asserting full_width padding behavior when the buffer is undisplayed but opts.winid is provided.

Comments suppressed due to low confidence (1)

lua/diffview/scene/layouts/diff_1_inline.lua:475

• Similarly in _render_inline, after awaiting _load_old_lines() and async.scheduler(), the validity check doesn’t confirm that the captured bufnr still matches the current self.b.file.bufnr. If self.b.file changes during the await, the render can target the wrong buffer. Recompute/compare bufnr after the yield before continuing.

  local old_lines = self._cached_old_lines
  if old_lines == nil then
    old_lines = await(self:_load_old_lines())
    await(async.scheduler())
    if
      not (
        self.b
        and self.b:is_valid()
        and self.b.file
        and self.b.file:is_valid()
        and api.nvim_buf_is_valid(bufnr)
      )
    then

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[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.