feat(previewer): add nvim buffer previewer

[linrongbin16]

relate: #491 .

Regresion test

Platforms

• [x] windows
• [x] macOS
• [ ] linux

Tasks

• [x] FzfxFiles
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-U/CTRL-R to switch between restricted/unrestricted mode, and the lines count is consistent when press multiple times.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to open file, and open the test/hello world.txt, test/goodbye world/goodbye.lua files.
  • Both fd and find works.
• [x] FzfxLiveGrep
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-U/CTRL-R to switch between restricted/unrestricted mode, and the lines count is consistent when press multiple times.
  • Use -w to match word only, use -g *.lua to search only lua files.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to open file, and open the test/hello world.txt, test/goodbye world/goodbye.lua files.
  • Both rg and grep works.
• [ ] FzfxBuffers
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-D to delete buffers, and delete the test/hello world.txt, test/goodbye world/goodbye.lua buffers.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to open file.
• [ ] FzfxGFiles
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-U/CTRL-W to switch between workspace/current folder mode.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to open file.
• [ ] FzfxGLiveGrep
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to open file.
• [ ] FzfxGStatus
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-U/CTRL-W to switch between workspace/current folder mode.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to open file.
  • Both with/without delta works.
• [ ] FzfxGBranches
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-R/CTRL-O to switch between local/remote branches.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to checkout branch.
• [ ] FzfxGCommits
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-U/CTRL-A to switch between git repo commits/current buffer commits.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to copy commit hash.
  • Both with/without delta works.
• [ ] FzfxGBlame
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to copy commit hash.
  • Both with/without delta works.
• [ ] FzfxLspDiagnostics
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-U/CTRL-W to switch between workspace/current buffer diagnostics.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to open file.
• [ ] FzfxLspDefinitions, FzfxLspTypeDefinitions, FzfxLspReferences, FzfxLspImplementations
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Go to definitions/references (this is the most 2 easiest use case when developing this lua plugin with lua_ls).
  • Press ESC to quit, ENTER to open file.
• [ ] FzfxLspIncomingCalls, FzfxLspOutgoingCalls
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Go to incoming/outgoing calls.
  • Press ESC to quit, ENTER to open file.
• [ ] FzfxCommands
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-U/CTRL-E/CTRL-A to switch between user/ex/all vim commands.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to feed vim command.
• [ ] FzfxKeyMaps
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-O/CTRL-I/CTRL-A/CTRL-V to switch between normal/insert/visual/all vim key mappings.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to feed vim keys.
• [ ] FzfxFileExplorer
  • Press CTRL-J/CTRL-K to move down/up and preview contents.
  • Press CTRL-U/CTRL-R to switch between filter/include hidden files mode.
  • Press ALT-L/ALT-H to cd into folder and cd upper folder.
  • Use V/W/P/R variants (visual selection, cursor word, yank text, resume last).
  • Press ESC to quit, ENTER to open file, and open the test/hello world.txt, test/goodbye world/goodbye.lua files.
  • All eza/lsd/ls works.

[linrongbin16]

The builtin nvim buffer previewer has much better syntax highlighting (since it's native nvim buffer), but the performance is unacceptable for me when scrolling up/down (in the left side).

This PR will need a lot of improvements to make it better, not only the performance, also the whole structure is ugly now.

https://github.com/linrongbin16/fzfx.nvim/assets/6496887/56320d6b-6970-4177-8c7f-2da1b81e2ca9

[linrongbin16]

Also, I noticed bat can custom new themes: https://github.com/sharkdp/bat?tab=readme-ov-file#adding-new-themes.

I am thinking retrieve RGB color codes from vim syntax highlighting, and create a custom theme for bat. Just like already did for fzf theme.

bat theme uses the .tmTheme: https://www.sublimetext.com/docs/color_schemes_tmtheme.html

[linrongbin16]

performance is good (on macOS) now, but still laggy on Windows. It should be related to Windows cmd.exe /C echo.

maybe could try to detect if there's external echo command, and use it first?

Windows user can use the improved bat theme in #557 .

[codecov[bot]]

Codecov Report

Attention: 376 lines in your changes are missing coverage. Please review.

Comparison is base (29d2217) 80.13% compared to head (4d371c6) 76.60%.

Files	Patch %	Lines
lua/fzfx/detail/general.lua	8.28%	166 Missing :warning:
lua/fzfx/detail/popup/buffer_popup_window.lua	67.77%	155 Missing :warning:
lua/fzfx/detail/popup.lua	49.15%	30 Missing :warning:
lua/fzfx/detail/popup/popup_helpers.lua	76.81%	16 Missing :warning:
lua/fzfx/detail/fzf_helpers.lua	96.10%	6 Missing :warning:
lua/fzfx/detail/popup/fzf_popup_window.lua	98.14%	2 Missing :warning:
lua/fzfx/helper/parsers.lua	87.50%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #556 +/- ## ========================================== - Coverage 80.13% 76.60% -3.53% ========================================== Files 45 48 +3 Lines 4526 5425 +899 ========================================== + Hits 3627 4156 +529 - Misses 899 1269 +370 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[linrongbin16]

Now the performance is quite good as well, even in Windows it's good.

I think I could cancel the other improve bat theme PR #557 , we may not need it.

Still something need to do:

1. Also parse fzf --border option as provider's window border.
2. Enable the preview window label.
3. Enable the default key bindings for preview window (alt+p: toggle preview window, ctrl+f/ctrl+b: scroll down/up)

[savchenko]

Massive effort! 🥳 Would you expose some highlight groups or pull everything from the loaded colourscheme?

Some bits seem to be a little off, e.g. cursorline in previewer from :FzfxLiveGrep

...and in nVim:

I have tried commenting-out fzf_color_opts, but to no effect.

[linrongbin16]

Massive effort! 🥳 Would you expose some highlight groups or pull everything from the loaded colourscheme?

Some bits seem to be a little off, e.g. cursorline in previewer from :FzfxLiveGrep

...and in nVim:

I have tried commenting-out fzf_color_opts, but to no effect.

this PR doesn't support 'FzfxLiveGrep' for now, it only affect the 'FzfxFiles' command.

it's only the first step, others will come after this PR get merged.