dotfiles/.vim/pack/plugins/start/vim-gitgutter/README.mkd

## vim-gitgutter

A Vim plugin which shows a git diff in the sign column.  It shows which lines have been added, modified, or removed.  You can also preview, stage, and undo individual hunks; and stage partial hunks.  The plugin also provides a hunk text object.

The signs are always up to date and the plugin never saves your buffer.

The name "gitgutter" comes from the Sublime Text 3 plugin which inspired this in 2013.

Features:

* Shows signs for added, modified, and removed lines.
* Runs the diffs asynchronously where possible.
* Ensures signs are always up to date.
* Never saves the buffer.
* Quick jumping between blocks of changed lines ("hunks").
* Stage/undo/preview individual hunks.
* Previews highlight intra-line changes.
* Stage partial hunks.
* Provides a hunk text object.
* Diffs against index (default) or any commit.
* Handles file moves / renames.
* Heeds git's "assume unchanged" bit.
* Allows folding all unchanged text.
* Provides fold text showing whether folded lines have been changed.
* Can load all hunk locations into quickfix list or the current window's location list.
* Handles line endings correctly, even with repos that do CRLF conversion.
* Handles clean/smudge filters.
* Optional line highlighting.
* Optional line number highlighting. (Only available in Neovim 0.3.2 or higher)
* Fully customisable (signs, sign column, line (number) highlights, mappings, extra git-diff arguments, etc).
* Can be toggled on/off, globally or per buffer.
* Preserves signs from other plugins.
* Does the right thing when viewing revisions with [fugitive](https://github.com/tpope/vim-fugitive)'s `:0Gclog`.
* Easy to integrate diff stats into status line; built-in integration with [vim-airline](https://github.com/bling/vim-airline/).
* Works with fish shell (in addition to the usual shells).

Constraints:

* Supports git only.  If you work with other version control systems, I recommend [vim-signify](https://github.com/mhinz/vim-signify).
* Relies on the `FocusGained` event.  If your terminal doesn't report focus events, either use something like [Terminus][] or set `let g:gitgutter_terminal_reports_focus=0`.  For tmux, `set -g focus-events on` in your tmux.conf.

Compatibility:

Compatible back to Vim 7.4, and probably 7.3.


### Screenshot

![screenshot](./screenshot.png?raw=true)

In the screenshot above you can see:

* Lines 183-184 are new.
* Lines 186-187 have been modified.
* The preview for the modified lines highlights changed regions within the line.


### Installation

First, install using your favourite package manager, or use Vim's built-in package support.

Vim:

```
mkdir -p ~/.vim/pack/airblade/start
cd ~/.vim/pack/airblade/start
git clone https://github.com/airblade/vim-gitgutter.git
vim -u NONE -c "helptags vim-gitgutter/doc" -c q
```

Neovim:

```
mkdir -p ~/.config/nvim/pack/airblade/start
cd ~/.config/nvim/pack/airblade/start
git clone https://github.com/airblade/vim-gitgutter.git
nvim -u NONE -c "helptags vim-gitgutter/doc" -c q
```

Second, ensure your `updatetime` and `signcolumn` options are set appropriately.

When you make a change to a file tracked by git, the diff markers should appear automatically after a short delay.  The delay is governed by vim's `updatetime` option; the default value is `4000`, i.e. 4 seconds, but I suggest reducing it to around 100ms (add `set updatetime=100` to your vimrc).  Note `updatetime` also controls the delay before vim writes its swap file (see `:help updatetime`).

The `signcolumn` option can have any value except `'off'`.


### Windows

There is a potential risk on Windows due to `cmd.exe` prioritising the current folder over folders in `PATH`.  If you have a file named `git.*` (i.e. with any extension in `PATHEXT`) in your current folder, it will be executed instead of git whenever the plugin calls git.

You can avoid this risk by configuring the full path to your git executable.  For example:

```viml
" This path probably won't work
let g:gitgutter_git_executable = 'C:\Program Files\Git\bin\git.exe'
```

Unfortunately I don't know the correct escaping for the path - if you do, please let me know!


### Getting started

When you make a change to a file tracked by git, the diff markers should appear automatically after a short delay.

You can jump between hunks with `[c` and `]c`.  You can preview, stage, and undo hunks with `<leader>hp`, `<leader>hs`, and `<leader>hu` respectively.

You cannot unstage a staged hunk.

After updating the signs, the plugin fires the `GitGutter` User autocommand.

After staging a hunk or part of a hunk, the plugin fires the `GitGutterStage` User autocommand.


#### Activation

You can explicitly turn vim-gitgutter off and on (defaults to on):

* turn off with `:GitGutterDisable`
* turn on with `:GitGutterEnable`
* toggle with `:GitGutterToggle`.

To toggle vim-gitgutter per buffer:

* turn off with `:GitGutterBufferDisable`
* turn on with `:GitGutterBufferEnable`
* toggle with `:GitGutterBufferToggle`

You can turn the signs on and off (defaults to on):

* turn on with `:GitGutterSignsEnable`
* turn off with `:GitGutterSignsDisable`
* toggle with `:GitGutterSignsToggle`.

And you can turn line highlighting on and off (defaults to off):

* turn on with `:GitGutterLineHighlightsEnable`
* turn off with `:GitGutterLineHighlightsDisable`
* toggle with `:GitGutterLineHighlightsToggle`.

Note that if you have line highlighting on and signs off, you will have an empty sign column – more accurately, a sign column with invisible signs.  This is because line highlighting requires signs and Vim/NeoVim always shows the sign column when there are signs even if the signs are invisible.

With Neovim 0.3.2 or higher, you can turn line number highlighting on and off (defaults to off):

* turn on with `:GitGutterLineNrHighlightsEnable`
* turn off with `:GitGutterLineNrHighlightsDisable`
* toggle with `:GitGutterLineNrHighlightsToggle`.

The same caveat applies to line number highlighting as to line highlighting just above.

If you switch off both line highlighting and signs, you won't see the sign column.

In older Vims (pre 8.1.0614 / Neovim 0.4.0) vim-gitgutter will suppress the signs when a file has more than 500 changes, to avoid slowing down the UI.  As soon as the number of changes falls below the limit vim-gitgutter will show the signs again.  You can configure the threshold with:

```viml
let g:gitgutter_max_signs = 500  " default value (Vim < 8.1.0614, Neovim < 0.4.0)
let g:gitgutter_max_signs = -1   " default value (otherwise)
```

You can also remove the limit by setting `g:gitgutter_max_signs = -1`.

#### Hunks

You can jump between hunks:

* jump to next hunk (change): `]c`
* jump to previous hunk (change): `[c`.

Both of those take a preceding count.

To set your own mappings for these, for example `]h` and `[h`:

```viml
nmap ]h <Plug>(GitGutterNextHunk)
nmap [h <Plug>(GitGutterPrevHunk)
```

When you jump between hunks, a message like `Hunk 4 of 11` is shown on the command line. If you want to turn the message off, you can use:

```viml
let g:gitgutter_show_msg_on_hunk_jumping = 0
```

You can load all your hunks into the quickfix list with `:GitGutterQuickFix`.  Note this ignores any unsaved changes in your buffers. If the option `g:gitgutter_use_location_list` is set, this command will load hunks into the current window's location list instead.  Use `:copen` (or `:lopen`) to open the quickfix / location list or add a custom command like this:

```viml
command! Gqf GitGutterQuickFix | copen
```

You can stage or undo an individual hunk when your cursor is in it:

* stage the hunk with `<Leader>hs` or
* undo it with `<Leader>hu`.

To stage part of an additions-only hunk by:

* either visually selecting the part you want and staging with your mapping, e.g. `<Leader>hs`;
* or using a range with the `GitGutterStageHunk` command, e.g. `:42,45GitGutterStageHunk`.

To stage part of any hunk:

* preview the hunk, e.g. `<Leader>hp`;
* move to the preview window, e.g. `:wincmd P`;
* delete the lines you do not want to stage;
* stage the remaining lines: either write (`:w`) the window or stage via `<Leader>hs` or `:GitGutterStageHunk`.

Note the above workflow is not possible if you have opted in to preview hunks with Vim's popup windows.

See the FAQ if you want to unstage staged changes.

The `.` command will work with both these if you install [repeat.vim](https://github.com/tpope/vim-repeat).

To set your own mappings for these, for example if you prefer `g`-based maps:

```viml
nmap ghs <Plug>(GitGutterStageHunk)
nmap ghu <Plug>(GitGutterUndoHunk)
```

And you can preview a hunk's changes with `<Leader>hp`.  The location of the preview window is configured with `g:gitgutter_preview_win_location` (default `'bo'`).  You can of course change this mapping, e.g:

```viml
nmap ghp <Plug>(GitGutterPreviewHunk)
```

A hunk text object is provided which works in visual and operator-pending modes.

- `ic` operates on all lines in the current hunk.
- `ac` operates on all lines in the current hunk and any trailing empty lines.

To re-map these, for example to `ih` and `ah`:

```viml
omap ih <Plug>(GitGutterTextObjectInnerPending)
omap ah <Plug>(GitGutterTextObjectOuterPending)
xmap ih <Plug>(GitGutterTextObjectInnerVisual)
xmap ah <Plug>(GitGutterTextObjectOuterVisual)
```

If you don't want vim-gitgutter to set up any mappings at all, use this:

```viml
let g:gitgutter_map_keys = 0
```

Finally, you can force vim-gitgutter to update its signs across all visible buffers with `:GitGutterAll`.

See the customisation section below for how to change the defaults.


### Vimdiff

Use the `GitGutterDiffOrig` command to open a vimdiff view of the current buffer, respecting `g:gitgutter_diff_relative_to` and `:gitgutter_diff_base`.


### Folding

Use the `GitGutterFold` command to fold all unchanged lines, leaving just the hunks visible.  Use `zr` to unfold 3 lines of context above and below a hunk.

Execute `GitGutterFold` a second time to restore the previous view.

Use `gitgutter#fold#foldtext()` to augment the default `foldtext()` with an indicator of whether the folded lines have been changed.

```viml
set foldtext=gitgutter#fold#foldtext()
```

For a closed fold with changed lines:

```
Default foldtext():         +-- 45 lines: abcdef
gitgutter#fold#foldtext():  +-- 45 lines (*): abcdef
```

You can use `gitgutter#fold#is_changed()` in your own `foldtext` expression to find out whether the folded lines have been changed.


### Status line

Call the `GitGutterGetHunkSummary()` function from your status line to get a list of counts of added, modified, and removed lines in the current buffer.  For example:

```viml
" Your vimrc
function! GitStatus()
  let [a,m,r] = GitGutterGetHunkSummary()
  return printf('+%d ~%d -%d', a, m, r)
endfunction
set statusline+=%{GitStatus()}
```


### Customisation

You can customise:

* The sign column's colours
* Whether or not the sign column is shown when there aren't any signs (defaults to no)
* How to handle non-gitgutter signs
* The signs' colours and symbols
* Line highlights
* Line number highlights (only in Neovim 0.3.2 or higher)
* The diff syntax colours used in the preview window
* The intra-line diff highlights used in the preview window
* Whether the diff is relative to the index (default) or working tree.
* The base of the diff
* Extra arguments for `git` when running `git diff`
* Extra arguments for `git diff`
* Key mappings
* Whether vim-gitgutter is on initially (defaults to on)
* Whether signs are shown (defaults to yes)
* Whether line highlighting is on initially (defaults to off)
* Whether line number highlighting is on initially (defaults to off)
* Whether vim-gitgutter runs asynchronously (defaults to yes)
* Whether to clobber or preserve non-gitgutter signs
* The priority of gitgutter's signs.
* Whether to use a floating/popup window for hunk previews
* The appearance of a floating/popup window for hunk previews
* Whether to populate the quickfix list or a location list with all hunks

Please note that vim-gitgutter won't override any colours or highlights you've set in your colorscheme.


#### Sign column

Set the `SignColumn` highlight group to change the sign column's colour.  For example:

```viml
" vim-gitgutter used to do this by default:
highlight! link SignColumn LineNr

" or you could do this:
highlight SignColumn guibg=whatever ctermbg=whatever
```

By default the sign column will appear when there are signs to show and disappear when there aren't.  To always have the sign column, add to your vimrc:

```viml
" Vim 7.4.2201
set signcolumn=yes
```

GitGutter can preserve or ignore non-gitgutter signs.  For Vim v8.1.0614 and later you can set gitgutter's signs' priorities with `g:gitgutter_sign_priority`, so gitgutter defaults to clobbering other signs.  For Neovim v0.4.0 and later you can set an expanding sign column so gitgutter again defaults to clobbering other signs.  Otherwise, gitgutter defaults to preserving other signs.  You can configure this with:

```viml
let g:gitgutter_sign_allow_clobber = 1
```


#### Signs' colours and symbols

If you or your colourscheme has defined `GitGutter*` highlight groups, the plugin will use them for the signs' colours.

If you want the background colours to match the sign column, but don't want to update the `GitGutter*` groups yourself, you can get the plugin to do it:

```viml
let g:gitgutter_set_sign_backgrounds = 1
```

If no `GitGutter*` highlight groups exist, the plugin will check the `Diff*` highlight groups.  If their foreground colours differ the plugin will use them; if not, these colours will be used:

```viml
highlight GitGutterAdd    guifg=#009900 ctermfg=2
highlight GitGutterChange guifg=#bbbb00 ctermfg=3
highlight GitGutterDelete guifg=#ff2222 ctermfg=1
```

To customise the symbols, add the following to your `~/.vimrc`:

```viml
let g:gitgutter_sign_added = 'xx'
let g:gitgutter_sign_modified = 'yy'
let g:gitgutter_sign_removed = 'zz'
let g:gitgutter_sign_removed_first_line = '^^'
let g:gitgutter_sign_removed_above_and_below = '{'
let g:gitgutter_sign_modified_removed = 'ww'
```


#### Line highlights

Similarly to the signs' colours, set up the following highlight groups in your colorscheme or `~/.vimrc`:

```viml
GitGutterAddLine          " default: links to DiffAdd
GitGutterChangeLine       " default: links to DiffChange
GitGutterDeleteLine       " default: links to DiffDelete
GitGutterChangeDeleteLine " default: links to GitGutterChangeLine, i.e. DiffChange
```

For example, in some colorschemes the `DiffText` highlight group is easier to read than `DiffChange`.  You could use it like this:

```viml
highlight link GitGutterChangeLine DiffText
```


#### Line number highlights

NOTE: This feature requires Neovim 0.3.2 or higher.

Similarly to the signs' colours, set up the following highlight groups in your colorscheme or `~/.vimrc`:

```viml
GitGutterAddLineNr          " default: links to CursorLineNr
GitGutterChangeLineNr       " default: links to CursorLineNr
GitGutterDeleteLineNr       " default: links to CursorLineNr
GitGutterChangeDeleteLineNr " default: links to GitGutterChangeLineNr
```

Maybe you think `CursorLineNr` is a bit annoying.  For example, you could use `Underlined` for this:

```viml
highlight link GitGutterChangeLineNr Underlined
```


#### The diff syntax colours used in the preview window

To change the diff syntax colours used in the preview window, set up the `diff*` highlight groups in your colorscheme or `~/.vimrc`:

```viml
diffAdded   " if not set: use GitGutterAdd's foreground colour
diffChanged " if not set: use GitGutterChange's foreground colour
diffRemoved " if not set: use GitGutterDelete's foreground colour
```

Note the `diff*` highlight groups are used in any buffer whose `'syntax'` is `diff`.


#### The intra-line diff highlights used in the preview window

To change the intra-line diff highlights used in the preview window, set up the following highlight groups in your colorscheme or `~/.vimrc`:

```viml
GitGutterAddIntraLine    " default: gui=reverse cterm=reverse
GitGutterDeleteIntraLine " default: gui=reverse cterm=reverse
```

For example, to use `DiffAdd` for intra-line added regions:

```viml
highlight link GitGutterAddIntraLine DiffAdd
```


#### Whether the diff is relative to the index or working tree

By default diffs are relative to the index.  How you can make them relative to the working tree:

```viml
let g:gitgutter_diff_relative_to = 'working_tree'
```


#### The base of the diff

By default buffers are diffed against the index.  However you can diff against any commit by setting:

```viml
let g:gitgutter_diff_base = '<commit SHA>'
```

If you are looking at a previous version of a file with Fugitive (e.g. via `:0Gclog`), gitgutter sets the diff base to the parent of the current revision.

This setting is ignored when the diffs are relative to the working tree.


#### Extra arguments for `git` when running `git diff`

If you want to pass extra arguments to `git` when running `git diff`, do so like this:

```viml
let g:gitgutter_git_args = '--git-dir-""'
```

#### Extra arguments for `git diff`

If you want to pass extra arguments to `git diff`, for example to ignore whitespace, do so like this:

```viml
let g:gitgutter_diff_args = '-w'
```

#### Key mappings

To disable all key mappings:

```viml
let g:gitgutter_map_keys = 0
```

See above for configuring maps for hunk-jumping and staging/undoing.


#### Use a custom `grep` command

If you use an alternative to grep, you can tell vim-gitgutter to use it here.

```viml
" Default:
let g:gitgutter_grep = 'grep'
```

#### To turn off vim-gitgutter by default

Add `let g:gitgutter_enabled = 0` to your `~/.vimrc`.


#### To turn off signs by default

Add `let g:gitgutter_signs = 0` to your `~/.vimrc`.


#### To turn on line highlighting by default

Add `let g:gitgutter_highlight_lines = 1` to your `~/.vimrc`.


#### To turn on line number highlighting by default

Add `let g:gitgutter_highlight_linenrs = 1` to your `~/.vimrc`.


#### To turn off asynchronous updates

By default diffs are run asynchronously.  To run diffs synchronously instead:

```viml
let g:gitgutter_async = 0
```


#### To use floating/popup windows for hunk previews

Add `let g:gitgutter_preview_win_floating = 1` to your `~/.vimrc`.  Note that on Vim this prevents you staging (partial) hunks via the preview window.


#### The appearance of a floating/popup window for hunk previews

Either set `g:gitgutter_floating_window_options` to a dictionary of the options you want.  This dictionary is passed directly to `popup_create()` (Vim) / `nvim_open_win()` (Neovim).

Or if you just want to override one or two of the defaults, you can do that with a file in an `after/` directory.  For example:

```viml
" ~/.vim/after/vim-gitgutter/overrides.vim
let g:gitgutter_floating_window_options['border'] = 'single'
```


#### To load all hunks into the current window's location list instead of the quickfix list

Add `let g:gitgutter_use_location_list = 1` to your `~/.vimrc`.


### Extensions

#### Operate on every line in a hunk

You can map an operator to do whatever you want to every line in a hunk.

Let's say, for example, you want to remove trailing whitespace.

```viml
function! CleanUp(...)
  if a:0  " opfunc
    let [first, last] = [line("'["), line("']")]
  else
    let [first, last] = [line("'<"), line("'>")]
  endif
  for lnum in range(first, last)
    let line = getline(lnum)

    " clean up the text, e.g.:
    let line = substitute(line, '\s\+$', '', '')

    call setline(lnum, line)
  endfor
endfunction

nmap <silent> <Leader>x :set opfunc=CleanUp<CR>g@
```

Then place your cursor in a hunk and type `\xic` (assuming a leader of `\`).

Alternatively you could place your cursor in a hunk, type `vic` to select it, then `:call CleanUp()`.


#### Operate on every changed line in a file

You can write a command to do whatever you want to every changed line in a file.

```viml
function! GlobalChangedLines(ex_cmd)
  for hunk in GitGutterGetHunks()
    for lnum in range(hunk[2], hunk[2]+hunk[3]-1)
      let cursor = getcurpos()
      silent! execute lnum.a:ex_cmd
      call setpos('.', cursor)
    endfor
  endfor
endfunction

command -nargs=1 Glines call GlobalChangedLines(<q-args>)
```

Let's say, for example, you want to remove trailing whitespace from all changed lines:

```viml
:Glines s/\s\+$//
```


#### Cycle through hunks in current buffer

This is like `:GitGutterNextHunk` but when it gets to the last hunk in the buffer it cycles around to the first.

```viml
function! GitGutterNextHunkCycle()
  let line = line('.')
  silent! GitGutterNextHunk
  if line('.') == line
    1
    GitGutterNextHunk
  endif
endfunction
```


#### Cycle through hunks in all buffers

You can use `:GitGutterQuickFix` to load all hunks into the quickfix list or the current window's location list.

Alternatively, given that`]c` and `[c` jump from one hunk to the next in the current buffer, you can use this code to jump to the next hunk no matter which buffer it's in.

```viml
function! NextHunkAllBuffers()
  let line = line('.')
  GitGutterNextHunk
  if line('.') != line
    return
  endif

  let bufnr = bufnr('')
  while 1
    bnext
    if bufnr('') == bufnr
      return
    endif
    if !empty(GitGutterGetHunks())
      1
      GitGutterNextHunk
      return
    endif
  endwhile
endfunction

function! PrevHunkAllBuffers()
  let line = line('.')
  GitGutterPrevHunk
  if line('.') != line
    return
  endif

  let bufnr = bufnr('')
  while 1
    bprevious
    if bufnr('') == bufnr
      return
    endif
    if !empty(GitGutterGetHunks())
      normal! G
      GitGutterPrevHunk
      return
    endif
  endwhile
endfunction

nmap <silent> ]c :call NextHunkAllBuffers()<CR>
nmap <silent> [c :call PrevHunkAllBuffers()<CR>
```


### FAQ

> How can I turn off realtime updates?

Add this to your vim configuration (in an `/after/plugin` directory):

```viml
" .vim/after/plugin/gitgutter.vim
autocmd! gitgutter CursorHold,CursorHoldI
```

> I turned off realtime updates, how can I have signs updated when I save a file?

If you really want to update the signs when you save a file, add this to your vimrc:

```viml
autocmd BufWritePost * GitGutter
```

> Why can't I unstage staged changes?

This plugin is for showing changes between the buffer and the index (and staging/undoing those changes).  Unstaging a staged hunk would require showing changes between the index and HEAD, which is out of scope.

> Why are the colours in the sign column weird?

Your colorscheme is configuring the `SignColumn` highlight group weirdly.  Please see the section above on customising the sign column.

> What happens if I also use another plugin which uses signs (e.g. Syntastic)?

You can configure whether GitGutter preserves or clobbers other signs using `g:gitgutter_sign_allow_clobber`.  Set to `1` to clobber other signs (default on Vim >= 8.1.0614 and NeoVim >= 0.4.0) or `0` to preserve them.


### Troubleshooting

#### When no signs are showing at all

Here are some things you can check:

* Try adding `let g:gitgutter_grep=''` to your vimrc.  If it works, the problem is grep producing non-plain output; e.g. ANSI escape codes or colours.
* Verify `:echo system("git --version")` succeeds.
* Verify your git config is compatible with the version of git returned by the command above.
* Verify your Vim supports signs (`:echo has('signs')` should give `1`).
* Verify your file is being tracked by git and has unstaged changes.  Check whether the plugin thinks git knows about your file: `:echo b:gitgutter.path` should show the path to the file in the repo.
* Execute `:sign place group=gitgutter`; you should see a list of signs.
  - If the signs are listed: this is a colorscheme / highlight problem.  Compare `:highlight GitGutterAdd` with `:highlight SignColumn`.
  - If no signs are listed: the call to git-diff is probably failing.  Add `let g:gitgutter_log=1` to your vimrc, restart, reproduce the problem, and look at the `gitgutter.log` file in the plugin's directory.

#### When the whole file is marked as added

* If you use zsh, and you set `CDPATH`, make sure `CDPATH` doesn't include the current directory.

#### When signs take a few seconds to appear

* Try reducing `updatetime`, e.g. `set updatetime=100`.  Note this also controls the delay before vim writes its swap file.

#### When signs don't update after focusing Vim

* Your terminal probably isn't reporting focus events.  Either try installing [Terminus][] or set `let g:gitgutter_terminal_reports_focus=0`.  For tmux, try `set -g focus-events on` in your tmux.conf.


### Shameless Plug

If this plugin has helped you, or you'd like to learn more about Vim, why not check out this screencast I wrote for PeepCode:

* [Smash Into Vim][siv]

This was one of PeepCode's all-time top three bestsellers and is now available at Pluralsight.


### Intellectual Property

Copyright Andrew Stewart, AirBlade Software Ltd.  Released under the MIT licence.


  [pathogen]: https://github.com/tpope/vim-pathogen
  [siv]: http://pluralsight.com/training/Courses/TableOfContents/smash-into-vim
  [terminus]: https://github.com/wincent/terminus