feat: add neogit support (#117)

## TODO

1. docs (vimdoc + readme) - this is a non-trivial feature
2. push luarocks version

## Problem

diffs.nvim only activates on `fugitive`, `git`, and `gitcommit`
filetypes.
Neogit uses its own custom filetypes (`NeogitStatus`,
`NeogitCommitView`,
`NeogitDiffView`) and doesn't set `b:git_dir`, so the plugin never
attaches
and repo root resolution fails for filetype detection within diff hunks.

## Solution

Two changes:

1. **`lua/diffs/init.lua`** — Add the three Neogit filetypes to the
default
`filetypes` list. The `FileType` autocmd in `plugin/diffs.lua` already
handles them correctly since the `is_fugitive_buffer` guard only applies
   to the `git` filetype.

2. **`lua/diffs/parser.lua`** — Add a CWD-based fallback in
`get_repo_root()`.
After the existing `b:diffs_repo_root` and `b:git_dir` checks, fall back
to
`vim.fn.getcwd()` via `git.get_repo_root()` (already cached). Without
this,
   the parser can't resolve filetypes for files in Neogit buffers.

Neogit's expanded diffs use standard unified diff format, so the parser
handles
them without modification.

Closes #110.

README.md

@@ -2,14 +2,15 @@
 
 **Syntax highlighting for diffs in Neovim**
 
-Enhance `vim-fugitive` and Neovim's built-in diff mode with language-aware
+Enhance [vim-fugitive](https://github.com/tpope/vim-fugitive),
-syntax highlighting.
+[Neogit](https://github.com/NeogitOrg/neogit), and Neovim's built-in diff mode
+with language-aware syntax highlighting.
 
 <video src="https://github.com/user-attachments/assets/24574916-ecb2-478e-a0ea-e4cdc971e310" width="100%" controls></video>
 
 ## Features
 
-- Treesitter syntax highlighting in fugitive diffs and commit views
+- Treesitter syntax highlighting in vim-fugitive, Neogit, and `diff` filetype
 - Character-level intra-line diff highlighting (with optional
   [vscode-diff](https://github.com/esmuellert/codediff.nvim) FFI backend for
   word-level accuracy)
@@ -37,6 +38,21 @@ luarocks install diffs.nvim
 :help diffs.nvim
 ```
 
+## FAQ
+
+**Does diffs.nvim support vim-fugitive/Neogit?**
+
+Yes. Enable it in your config:
+
+```lua
+vim.g.diffs = {
+  fugitive = true,
+  neogit = true,
+}
+```
+
+See the documentation for more information.
+
 ## Known Limitations
 
 - **Incomplete syntax context**: Treesitter parses each diff hunk in isolation.

doc/diffs.nvim.txt

@@ -7,8 +7,8 @@ License: MIT
 INTRODUCTION                                                       *diffs.nvim*
 
 diffs.nvim adds syntax highlighting to diff views. It overlays language-aware
-highlights on top of default diff highlighting in vim-fugitive and Neovim's
+highlights on top of default diff highlighting in vim-fugitive, Neogit, and
-built-in diff mode.
+Neovim's built-in diff mode.
 
 Features: ~
 - Syntax highlighting in |:Git| summary diffs and commit detail views
@@ -53,7 +53,9 @@ Configuration is done via `vim.g.diffs`. Set this before the plugin loads:
     vim.g.diffs = {
       debug = false,
       hide_prefix = false,
-      filetypes = { 'fugitive', 'git', 'gitcommit' },
+      fugitive = false,
+      neogit = false,
+      extra_filetypes = {},
       highlights = {
         background = true,
         gutter = true,
@@ -83,10 +85,6 @@ Configuration is done via `vim.g.diffs`. Set this before the plugin loads:
         },
         overrides = {},
       },
-      fugitive = {
-        horizontal = 'du',
-        vertical = 'dU',
-      },
       conflict = {
         enabled = true,
         disable_diagnostics = true,
@@ -116,14 +114,36 @@ Configuration is done via `vim.g.diffs`. Set this before the plugin loads:
                              is also enabled, the overlay inherits the line's
                              background color.
 
-        {filetypes}          (table, default: {'fugitive','git','gitcommit'})
+        {fugitive}           (boolean|table, default: false)
-                             List of filetypes that trigger attachment. Add
+                             Enable vim-fugitive integration. Accepts
-                             `'diff'` to enable highlighting in plain `.diff`
+                             `true`, `false`, or a table with sub-options
-                             and `.patch` files: >lua
+                             (see |diffs.FugitiveConfig|). When enabled,
+                             the `fugitive` filetype is active and status
+                             buffer keymaps are registered. >lua
+                                 vim.g.diffs = { fugitive = true }
                                  vim.g.diffs = {
-                                   filetypes = {
+                                   fugitive = { horizontal = 'dd' },
-                                     'fugitive', 'git', 'gitcommit', 'diff',
+                                 }
-                                   },
+<
+
+        {neogit}             (boolean|table, default: false)
+                             Enable Neogit integration. Accepts `true`,
+                             `false`, or `{ enabled = false }`. When
+                             enabled, `NeogitStatus`, `NeogitCommitView`,
+                             and `NeogitDiffView` filetypes are active and
+                             Neogit highlight overrides are applied. See
+                             |diffs-neogit|. >lua
+                                 vim.g.diffs = { neogit = false }
+<
+
+        {extra_filetypes}    (table, default: {})
+                             Additional filetypes to attach to, beyond the
+                             built-in `git`, `gitcommit`, and any enabled
+                             integration filetypes. Use this to enable
+                             highlighting in plain `.diff` / `.patch`
+                             files: >lua
+                                 vim.g.diffs = {
+                                   extra_filetypes = { 'diff' },
                                  }
 <
 
@@ -131,10 +151,6 @@ Configuration is done via `vim.g.diffs`. Set this before the plugin loads:
                              Controls which highlight features are enabled.
                              See |diffs.Highlights| for fields.
 
-        {fugitive}           (table, default: see below)
-                             Fugitive status buffer keymap options.
-                             See |diffs.FugitiveConfig| for fields.
-
         {conflict}           (table, default: see below)
                              Inline merge conflict resolution options.
                              See |diffs.ConflictConfig| for fields.
@@ -422,12 +438,20 @@ Configuration: ~
 >lua
     vim.g.diffs = {
       fugitive = {
+        enabled = true,     -- false to disable fugitive integration entirely
         horizontal = 'du',  -- keymap for horizontal split, false to disable
         vertical = 'dU',    -- keymap for vertical split, false to disable
       },
     }
 <
     Fields: ~
+        {enabled}            (boolean, default: false)
+                             Enable fugitive integration. When false, the
+                             `fugitive` filetype is excluded and no status
+                             buffer keymaps are registered. Shorthand:
+                             `fugitive = false` is equivalent to
+                             `fugitive = { enabled = false }`.
+
         {horizontal}         (string|false, default: 'du')
                              Keymap for unified diff in horizontal split.
                              Set to `false` to disable.
@@ -579,6 +603,31 @@ The working file buffer is modified in place; save it when ready.
 Phase 1 inline conflict highlights (see |diffs-conflict|) are refreshed
 automatically after each resolution.
 
+==============================================================================
+NEOGIT                                                          *diffs-neogit*
+
+diffs.nvim works with Neogit (https://github.com/NeogitOrg/neogit) out of
+the box. Enable Neogit support in your config: >lua
+    vim.g.diffs = { neogit = true }
+<
+
+When a diff is expanded in a Neogit buffer (e.g., via TAB on a file in the
+status view), diffs.nvim applies treesitter syntax highlighting and
+intra-line diffs to the hunk lines, just as it does for fugitive.
+
+Neogit highlight overrides: ~
+On first attach to a Neogit buffer, diffs.nvim overrides Neogit's diff
+highlight groups (`NeogitDiffAdd*`, `NeogitDiffDelete*`,
+`NeogitDiffContext*`, `NeogitHunkHeader*`, `NeogitDiffHeader*`, etc.) by
+setting them to empty (`{}`). This gives diffs.nvim sole control of diff
+line visuals. The overrides are reapplied on `ColorScheme` since Neogit
+re-defines its groups then. When `neogit = false`, no highlight overrides
+are applied.
+
+Deprecated: ~
+The `filetypes` config key still works but is deprecated and will be
+removed in 0.3.0. Use `fugitive`, `neogit`, and `extra_filetypes` instead.
+
 ==============================================================================
 API                                                                *diffs-api*
 
@@ -600,7 +649,7 @@ refresh({bufnr})                                           *diffs.refresh()*
 IMPLEMENTATION                                        *diffs-implementation*
 
 Summary / commit detail views: ~
-1. `FileType` autocmd for configured filetypes (see {filetypes}) triggers
+1. `FileType` autocmd for computed filetypes (see |diffs-config|) triggers
    |diffs.attach()|. For `git` buffers, only `fugitive://` URIs are attached.
 2. The buffer is parsed to detect file headers (`M path/to/file`,
    `diff --git a/... b/...`) and hunk headers (`@@ -10,3 +10,4 @@`)

lua/diffs/highlight.lua

@@ -443,18 +443,11 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
     end
 
     if opts.highlights.background and is_diff_line then
-      pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, {
+      local ext = { line_hl_group = line_hl, priority = p.line_bg }
-        end_row = buf_line + 1,
-        hl_group = line_hl,
-        hl_eol = true,
-        priority = p.line_bg,
-      })
       if opts.highlights.gutter then
-        pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, {
+        ext.number_hl_group = number_hl
-          number_hl_group = number_hl,
-          priority = p.line_bg,
-        })
       end
+      pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, ext)
     end
 
     if is_marker and line_len > pw then

lua/diffs/init.lua

@@ -33,9 +33,13 @@
 ---@field priorities diffs.PrioritiesConfig
 
 ---@class diffs.FugitiveConfig
+---@field enabled boolean
 ---@field horizontal string|false
 ---@field vertical string|false
 
+---@class diffs.NeogitConfig
+---@field enabled boolean
+
 ---@class diffs.ConflictKeymaps
 ---@field ours string|false
 ---@field theirs string|false
@@ -56,9 +60,11 @@
 ---@class diffs.Config
 ---@field debug boolean|string
 ---@field hide_prefix boolean
----@field filetypes string[]
+---@field filetypes? string[] @deprecated use fugitive, neogit, extra_filetypes
+---@field extra_filetypes string[]
 ---@field highlights diffs.Highlights
 ---@field fugitive diffs.FugitiveConfig
+---@field neogit diffs.NeogitConfig
 ---@field conflict diffs.ConflictConfig
 
 ---@class diffs
@@ -108,7 +114,7 @@ end
 local default_config = {
   debug = false,
   hide_prefix = false,
-  filetypes = { 'fugitive', 'git', 'gitcommit' },
+  extra_filetypes = {},
   highlights = {
     background = true,
     gutter = true,
@@ -137,9 +143,13 @@ local default_config = {
     },
   },
   fugitive = {
+    enabled = false,
     horizontal = 'du',
     vertical = 'dU',
   },
+  neogit = {
+    enabled = false,
+  },
   conflict = {
     enabled = true,
     disable_diagnostics = true,
@@ -188,6 +198,31 @@ function M.is_fugitive_buffer(bufnr)
   return vim.api.nvim_buf_get_name(bufnr):match('^fugitive://') ~= nil
 end
 
+---@param opts table
+---@return string[]
+function M.compute_filetypes(opts)
+  if opts.filetypes then
+    return opts.filetypes
+  end
+  local fts = { 'git', 'gitcommit' }
+  local fug = opts.fugitive
+  if fug == true or (type(fug) == 'table' and fug.enabled ~= false) then
+    table.insert(fts, 'fugitive')
+  end
+  local neo = opts.neogit
+  if neo == true or (type(neo) == 'table' and neo.enabled ~= false) then
+    table.insert(fts, 'NeogitStatus')
+    table.insert(fts, 'NeogitCommitView')
+    table.insert(fts, 'NeogitDiffView')
+  end
+  if type(opts.extra_filetypes) == 'table' then
+    for _, ft in ipairs(opts.extra_filetypes) do
+      table.insert(fts, ft)
+    end
+  end
+  return fts
+end
+
 local dbg = log.dbg
 
 ---@param bufnr integer
@@ -387,6 +422,34 @@ local function compute_highlight_groups()
   end
 end
 
+local neogit_attached = false
+
+local neogit_hl_groups = {
+  'NeogitDiffAdd',
+  'NeogitDiffAddCursor',
+  'NeogitDiffAddHighlight',
+  'NeogitDiffDelete',
+  'NeogitDiffDeleteCursor',
+  'NeogitDiffDeleteHighlight',
+  'NeogitDiffContext',
+  'NeogitDiffContextCursor',
+  'NeogitDiffContextHighlight',
+  'NeogitDiffHeader',
+  'NeogitDiffHeaderHighlight',
+  'NeogitHunkHeader',
+  'NeogitHunkHeaderCursor',
+  'NeogitHunkHeaderHighlight',
+  'NeogitHunkMergeHeader',
+  'NeogitHunkMergeHeaderCursor',
+  'NeogitHunkMergeHeaderHighlight',
+}
+
+local function override_neogit_highlights()
+  for _, name in ipairs(neogit_hl_groups) do
+    vim.api.nvim_set_hl(0, name, {})
+  end
+end
+
 local function init()
   if initialized then
     return
@@ -395,6 +458,35 @@ local function init()
 
   local opts = vim.g.diffs or {}
 
+  if opts.filetypes then
+    vim.deprecate(
+      'vim.g.diffs.filetypes',
+      'fugitive, neogit, and extra_filetypes',
+      '0.3.0',
+      'diffs.nvim'
+    )
+  end
+
+  if opts.fugitive == true then
+    opts.fugitive = { enabled = true }
+  elseif opts.fugitive == false then
+    opts.fugitive = { enabled = false }
+  elseif opts.fugitive == nil then
+    opts.fugitive = nil
+  elseif type(opts.fugitive) == 'table' and opts.fugitive.enabled == nil then
+    opts.fugitive.enabled = true
+  end
+
+  if opts.neogit == true then
+    opts.neogit = { enabled = true }
+  elseif opts.neogit == false then
+    opts.neogit = { enabled = false }
+  elseif opts.neogit == nil then
+    opts.neogit = nil
+  elseif type(opts.neogit) == 'table' and opts.neogit.enabled == nil then
+    opts.neogit.enabled = true
+  end
+
   vim.validate({
     debug = {
       opts.debug,
@@ -404,7 +496,9 @@ local function init()
       'boolean or string (file path)',
     },
     hide_prefix = { opts.hide_prefix, 'boolean', true },
-    filetypes = { opts.filetypes, 'table', true },
+    fugitive = { opts.fugitive, 'table', true },
+    neogit = { opts.neogit, 'table', true },
+    extra_filetypes = { opts.extra_filetypes, 'table', true },
     highlights = { opts.highlights, 'table', true },
   })
 
@@ -472,23 +566,30 @@ local function init()
 
   if opts.fugitive then
     vim.validate({
+      ['fugitive.enabled'] = { opts.fugitive.enabled, 'boolean', true },
       ['fugitive.horizontal'] = {
         opts.fugitive.horizontal,
         function(v)
-          return v == false or type(v) == 'string'
+          return v == nil or v == false or type(v) == 'string'
         end,
         'string or false',
       },
       ['fugitive.vertical'] = {
         opts.fugitive.vertical,
         function(v)
-          return v == false or type(v) == 'string'
+          return v == nil or v == false or type(v) == 'string'
         end,
         'string or false',
       },
     })
   end
 
+  if opts.neogit then
+    vim.validate({
+      ['neogit.enabled'] = { opts.neogit.enabled, 'boolean', true },
+    })
+  end
+
   if opts.conflict then
     vim.validate({
       ['conflict.enabled'] = { opts.conflict.enabled, 'boolean', true },
@@ -583,6 +684,9 @@ local function init()
   vim.api.nvim_create_autocmd('ColorScheme', {
     callback = function()
       compute_highlight_groups()
+      if neogit_attached then
+        vim.schedule(override_neogit_highlights)
+      end
       for bufnr, _ in pairs(attached_buffers) do
         invalidate_cache(bufnr)
       end
@@ -701,6 +805,11 @@ function M.attach(bufnr)
   end
   attached_buffers[bufnr] = true
 
+  if not neogit_attached and config.neogit.enabled and vim.bo[bufnr].filetype:match('^Neogit') then
+    neogit_attached = true
+    vim.schedule(override_neogit_highlights)
+  end
+
   dbg('attaching to buffer %d', bufnr)
 
   ensure_cache(bufnr)

lua/diffs/parser.lua

@@ -110,7 +110,9 @@ local function get_repo_root(bufnr)
     return vim.fn.fnamemodify(git_dir, ':h')
   end
 
-  return nil
+  local cwd = vim.fn.getcwd()
+  local git = require('diffs.git')
+  return git.get_repo_root(cwd .. '/.')
 end
 
 ---@param bufnr integer
@@ -194,7 +196,13 @@ function M.parse_buffer(bufnr)
 
   for i, line in ipairs(lines) do
     local diff_git_file = line:match('^diff %-%-git a/.+ b/(.+)$')
-    local filename = line:match('^[MADRCU%?!]%s+(.+)$') or diff_git_file
+    local neogit_file = line:match('^modified%s+(.+)$')
+      or line:match('^new file%s+(.+)$')
+      or line:match('^deleted%s+(.+)$')
+      or line:match('^renamed%s+(.+)$')
+      or line:match('^copied%s+(.+)$')
+    local bare_file = not hunk_start and line:match('^([^%s]+%.[^%s]+)$')
+    local filename = line:match('^[MADRCU%?!]%s+(.+)$') or diff_git_file or neogit_file or bare_file
     if filename then
       is_unified_diff = diff_git_file ~= nil
       flush_hunk()

plugin/diffs.lua

@@ -6,7 +6,7 @@ vim.g.loaded_diffs = 1
 require('diffs.commands').setup()
 
 vim.api.nvim_create_autocmd('FileType', {
-  pattern = (vim.g.diffs or {}).filetypes or { 'fugitive', 'git', 'gitcommit' },
+  pattern = require('diffs').compute_filetypes(vim.g.diffs or {}),
   callback = function(args)
     local diffs = require('diffs')
     if args.match == 'git' and not diffs.is_fugitive_buffer(args.buf) then

spec/highlight_spec.lua

@@ -287,7 +287,7 @@ describe('highlight', function()
       local extmarks = get_extmarks(bufnr)
       local has_diff_add = false
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_group == 'DiffsAdd' then
+        if mark[4] and mark[4].line_hl_group == 'DiffsAdd' then
           has_diff_add = true
           break
         end
@@ -320,7 +320,7 @@ describe('highlight', function()
       local extmarks = get_extmarks(bufnr)
       local has_diff_delete = false
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_group == 'DiffsDelete' then
+        if mark[4] and mark[4].line_hl_group == 'DiffsDelete' then
           has_diff_delete = true
           break
         end
@@ -386,7 +386,7 @@ describe('highlight', function()
       local extmarks = get_extmarks(bufnr)
       local has_diff_add = false
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_group == 'DiffsAdd' then
+        if mark[4] and mark[4].line_hl_group == 'DiffsAdd' then
           has_diff_add = true
           break
         end
@@ -500,7 +500,7 @@ describe('highlight', function()
       local extmarks = get_extmarks(bufnr)
       local has_diff_add = false
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_group == 'DiffsAdd' then
+        if mark[4] and mark[4].line_hl_group == 'DiffsAdd' then
           has_diff_add = true
           break
         end
@@ -560,7 +560,7 @@ describe('highlight', function()
       delete_buffer(bufnr)
     end)
 
-    it('uses hl_group not line_hl_group for line backgrounds', function()
+    it('uses line_hl_group for line backgrounds', function()
       local bufnr = create_buffer({
         '@@ -1,2 +1,1 @@',
         '-local x = 1',
@@ -582,17 +582,19 @@ describe('highlight', function()
       )
 
       local extmarks = get_extmarks(bufnr)
+      local found = false
       for _, mark in ipairs(extmarks) do
         local d = mark[4]
-        if d and (d.hl_group == 'DiffsAdd' or d.hl_group == 'DiffsDelete') then
+        if d and (d.line_hl_group == 'DiffsAdd' or d.line_hl_group == 'DiffsDelete') then
-          assert.is_true(d.hl_eol == true)
+          found = true
-          assert.is_nil(d.line_hl_group)
+          assert.is_nil(d.hl_eol)
         end
       end
+      assert.is_true(found)
       delete_buffer(bufnr)
     end)
 
-    it('hl_eol background extmarks are multiline so hl_eol takes effect', function()
+    it('line_hl_group background extmarks are single-line', function()
       local bufnr = create_buffer({
         '@@ -1,2 +1,1 @@',
         '-local x = 1',
@@ -616,8 +618,8 @@ describe('highlight', function()
       local extmarks = get_extmarks(bufnr)
       for _, mark in ipairs(extmarks) do
         local d = mark[4]
-        if d and (d.hl_group == 'DiffsAdd' or d.hl_group == 'DiffsDelete') then
+        if d and (d.line_hl_group == 'DiffsAdd' or d.line_hl_group == 'DiffsDelete') then
-          assert.is_true(d.end_row > mark[2])
+          assert.is_nil(d.end_row)
         end
       end
       delete_buffer(bufnr)
@@ -771,7 +773,7 @@ describe('highlight', function()
         if d then
           if d.hl_group == 'DiffsClear' then
             table.insert(priorities.clear, d.priority)
-          elseif d.hl_group == 'DiffsAdd' or d.hl_group == 'DiffsDelete' then
+          elseif d.line_hl_group == 'DiffsAdd' or d.line_hl_group == 'DiffsDelete' then
             table.insert(priorities.line_bg, d.priority)
           elseif d.hl_group == 'DiffsAddText' or d.hl_group == 'DiffsDeleteText' then
             table.insert(priorities.char_bg, d.priority)
@@ -871,8 +873,8 @@ describe('highlight', function()
       local extmarks = get_extmarks(bufnr)
       local line_bgs = {}
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].hl_eol then
+        if mark[4] and mark[4].line_hl_group then
-          line_bgs[mark[2]] = mark[4].hl_group
+          line_bgs[mark[2]] = mark[4].line_hl_group
         end
       end
       assert.is_nil(line_bgs[1])
@@ -1063,8 +1065,8 @@ describe('highlight', function()
       local marker_text = {}
       for _, mark in ipairs(extmarks) do
         local d = mark[4]
-        if d and d.hl_eol then
+        if d and d.line_hl_group then
-          line_bgs[mark[2]] = d.hl_group
+          line_bgs[mark[2]] = d.line_hl_group
         end
         if d and d.number_hl_group then
           gutter_hls[mark[2]] = d.number_hl_group

spec/parser_spec.lua

@@ -587,5 +587,86 @@ describe('parser', function()
       assert.are.equal('/tmp/test-repo', hunks[1].repo_root)
       delete_buffer(bufnr)
     end)
+
+    it('detects neogit modified prefix', function()
+      local bufnr = create_buffer({
+        'modified   hello.lua',
+        '@@ -1,2 +1,3 @@',
+        ' local M = {}',
+        '+local x = 1',
+        ' return M',
+      })
+      local hunks = parser.parse_buffer(bufnr)
+
+      assert.are.equal(1, #hunks)
+      assert.are.equal('hello.lua', hunks[1].filename)
+      assert.are.equal('lua', hunks[1].ft)
+      assert.are.equal(3, #hunks[1].lines)
+      delete_buffer(bufnr)
+    end)
+
+    it('detects neogit new file prefix', function()
+      local bufnr = create_buffer({
+        'new file   hello.lua',
+        '@@ -0,0 +1,2 @@',
+        '+local M = {}',
+        '+return M',
+      })
+      local hunks = parser.parse_buffer(bufnr)
+
+      assert.are.equal(1, #hunks)
+      assert.are.equal('hello.lua', hunks[1].filename)
+      assert.are.equal('lua', hunks[1].ft)
+      assert.are.equal(2, #hunks[1].lines)
+      delete_buffer(bufnr)
+    end)
+
+    it('detects neogit deleted prefix', function()
+      local bufnr = create_buffer({
+        'deleted   hello.lua',
+        '@@ -1,2 +0,0 @@',
+        '-local M = {}',
+        '-return M',
+      })
+      local hunks = parser.parse_buffer(bufnr)
+
+      assert.are.equal(1, #hunks)
+      assert.are.equal('hello.lua', hunks[1].filename)
+      assert.are.equal('lua', hunks[1].ft)
+      assert.are.equal(2, #hunks[1].lines)
+      delete_buffer(bufnr)
+    end)
+
+    it('detects bare filename for untracked files', function()
+      local bufnr = create_buffer({
+        'newfile.rs',
+        '@@ -0,0 +1,3 @@',
+        '+fn main() {',
+        '+    println!("hello");',
+        '+}',
+      })
+      local hunks = parser.parse_buffer(bufnr)
+
+      assert.are.equal(1, #hunks)
+      assert.are.equal('newfile.rs', hunks[1].filename)
+      assert.are.equal(3, #hunks[1].lines)
+      delete_buffer(bufnr)
+    end)
+
+    it('does not match section headers as bare filenames', function()
+      local bufnr = create_buffer({
+        'Untracked files (1)',
+        'newfile.rs',
+        '@@ -0,0 +1,3 @@',
+        '+fn main() {',
+        '+    println!("hello");',
+        '+}',
+      })
+      local hunks = parser.parse_buffer(bufnr)
+
+      assert.are.equal(1, #hunks)
+      assert.are.equal('newfile.rs', hunks[1].filename)
+      delete_buffer(bufnr)
+    end)
   end)
 end)