Add option to open commit diff in a buffer from Commits or BCommits, a la FZF

[VVKot]

Is your feature request related to a problem? Please describe.
Currently action mapped in commits picker is checkout. This is quite often not what I want and I would rather have an option to see commit's diff in a buffer. Diff in the preview would somewhat solve the problem. It still does not give all the power and flexibility of a separate buffer though.

Describe the solution you'd like
There is an option to override action on from commits/bcommits, so that instead of checking out this commit I get a buffer with this commit's diff.

Describe alternatives you've considered
Continuing to use fzf.vim for this.

Additional context
There is #528 which I assume will unblock this?

[Conni2461]

#528 implements open diff for bcommits when doing <c-v>, <c-x> or <c-t> not commits tho

[VVKot]

I guess what I really want is integration with fugitive (because that's what fzf.vim) does. I imagine that would require a bit more thought.

[VVKot]

For future readers - what I ended up using instead: https://github.com/junegunn/gv.vim

[fdschmidt93]

With diffview.nvim you can easily write actions that I think achieve what you were looking for as suggested in this thread

local action_state = require "telescope.actions.state"
local ts_utils = require "telescope.utils"

-- in your setup
  pickers = {
    git_commits = {
      mappings = {
        i = {
          ["your mapping here"] = function(prompt_bufnr)
            actions.close(prompt_bufnr)
            local value = action_state.get_selected_entry().value
            -- changes from commit against current index
            local cmd = "DiffviewOpen " .. value
            -- for changes from one commit to the previous one
            local cmd = "DiffviewOpen " .. value .. "~1.." .. value
            --- feature branch against branch of your choice
            local rev = ts_utils.get_os_command_output({ "git", "rev-parse", "branch-name-here" }, vim.loop.cwd())[1]
            cmd = "DiffviewOpen " .. rev .. " " .. value)
            vim.cmd(cmd)
          end,
        }
      }
    }

[rx2130]

I guess what I really want is integration with fugitive (because that's what fzf.vim) does. I imagine that would require a bit more thought.

+1. I also much prefer fzf :Commits/:BCommits behavior that open selected commit in fugitive instead of telescope checkout to that commit. I suppose most often people want to read commit rather than checkout?

FWIW I have being using the following code to open in fugitive.

actions.git_fugitive = function(prompt_bufnr)
  local cwd = action_state.get_current_picker(prompt_bufnr).cwd
  local selection = action_state.get_selected_entry()
  actions.close(prompt_bufnr)

  sha = selection.value
  vim.cmd("execute 'vsplit' FugitiveFind(luaeval('sha'))")
end