How can I write a source for Jujutsu (jj) commands?

[oatovar]

I've started using Jujutsu (jj) and would like to use the Snacks picker to view the changeset log, operation log, and more. I took a look at #1966, and tried to use that to create my own source, but couldn't get it to work. Is there any contributing guide that I can follow? Any help is appreciated.

[drowning-cat]

There is no guide. Better look at the source code:

What are finder, format, transform?

snacks.nvim/lua/snacks/picker/config/sources.lua

Lines 314 to 325 in bc0630e

	M.git_status = {
	finder = "git_status",
	format = "git_status",
	preview = "git_status",
	win = {
	input = {
	keys = {
	["<Tab>"] = { "git_stage", mode = { "n", "i" } },
	},
	},
	},
	}

opts.finder:

snacks.nvim/lua/snacks/picker/source/git.lua

Lines 177 to 210 in bc0630e

	function M.status(opts, ctx)
	local args = git_args(opts.args, "--no-pager", "status", "-uall", "--porcelain=v1", "-z")
	if opts.ignored then
	table.insert(args, "--ignored=matching")
	end
	local cwd = svim.fs.normalize(opts and opts.cwd or uv.cwd() or ".") or nil
	cwd = Snacks.git.get_root(cwd)
	local prev ---@type snacks.picker.finder.Item?
	return require("snacks.picker.source.proc").proc({
	opts,
	{
	sep = "\0",
	cwd = cwd,
	cmd = "git",
	args = args,
	---@param item snacks.picker.finder.Item
	transform = function(item)
	local status, file = item.text:match("^(..) (.+)$")
	if status then
	item.cwd = cwd
	item.status = status
	item.file = file
	prev = item
	elseif prev and prev.status:find("R") then
	prev.rename = item.text
	return false
	else
	return false
	end
	end,
	},
	}, ctx)
	end

opts.format:

snacks.nvim/lua/snacks/picker/format.lua

Lines 533 to 560 in bc0630e

	function M.git_status(item, picker)
	local ret = {} ---@type snacks.picker.Highlight[]
	local a = Snacks.picker.util.align
	local s = vim.trim(item.status):sub(1, 1)
	local hls = {
	["A"] = "SnacksPickerGitStatusAdded",
	["M"] = "SnacksPickerGitStatusModified",
	["D"] = "SnacksPickerGitStatusDeleted",
	["R"] = "SnacksPickerGitStatusRenamed",
	["C"] = "SnacksPickerGitStatusCopied",
	["?"] = "SnacksPickerGitStatusUntracked",
	}
	local hl = hls[s] or "SnacksPickerGitStatus"
	ret[#ret + 1] = { a(item.status, 2, { align = "right" }), hl }
	ret[#ret + 1] = { " " }
	if item.rename then
	local file = item.file
	item.file = item.rename
	item._path = nil
	vim.list_extend(ret, M.filename(item, picker))
	item.file = file
	item._path = nil
	ret[#ret + 1] = { "-> ", "SnacksPickerDelim" }
	ret[#ret + 1] = { " " }
	end
	vim.list_extend(ret, M.filename(item, picker))
	return ret
	end

opts.preview:

snacks.nvim/lua/snacks/picker/preview.lua

Lines 392 to 399 in bc0630e

	function M.git_status(ctx)
	local ss = ctx.item.status
	if ss:find("^[A?]") then
	M.file(ctx)
	else
	M.git_diff(ctx)
	end
	end

[drowning-cat]

Provide an example of the code you are working on.

[oatovar]

Thank you for the links! I've made some progress, and have managed to list the changes with the following.

          function()
            local Snacks = require "snacks"
            local Proc = require "snacks.picker.source.proc"

            Snacks.picker.pick {
              finder = function(opts, ctx)
                local cwd = vim.fs.normalize(opts and opts.cwd or vim.uv.cwd() or ".") or nil
                cwd = Snacks.git.get_root(cwd)

                return Proc.proc({
                  opts,
                  {
                    sep = "\0",
                    cwd = cwd,
                    cmd = "jj",
                    args = {
                      "log",
                      "--color=never",
                      "--no-graph",
                      "-T",
                      'separate(" ", change_id.shortest(), commit_id.short(), author.email(), description.first_line()) ++ "\\0"',
                      "-r",
                      "all() ~ @",
                    },
                    transform = function(item)
                      local change_id, commit_id, author, msg = item.text:match "^(%S+) (%S+) (%S+) (.+)$"
                      item.cwd = cwd
                      item.change_id = change_id
                      item.commit_id = commit_id
                      item.author = author
                      item.msg = msg
                    end,
                  },
                }, ctx)
              end,
            }
          end,

I now need to implement a preview that shows the changes.

[drowning-cat]

Picker jj_log

opts = {
  picker = {
    previewers = {
      jj = {
        delta = true,
      },
    },
    sources = {
      jj_log = {
        title = 'jj log',
        supports_live = false,
        reversed = nil,
        cwd = nil,
        args = nil,
        finder = function(opts, ctx)
          local cwd
          cwd = opts and opts.cwd or vim.uv.cwd() or '.'
          cwd = svim.fs.normalize(cwd)
          cwd = vim.fs.root(cwd or 0, '.jj')
          if not cwd then
            Snacks.notify.error 'Cannot find `.jj` folder. To initialize a repository use `jj git init .`'
            ctx.picker.closed = true
            return {}
          end
          local template = [[
            separate("\0",
              self.change_id().shortest(),
              self.change_id().shortest(8),
              commit_timestamp(self).format("%Y-%m-%d %H:%M"),
              commit_id.shortest(8),
              if(description,
                description.first_line(),
                label(
                  if(empty, "empty"),
                  if(root, "root()", description_placeholder)
                ),
              )
            ) ++ "\n"
          ]]
          local cmd = 'jj'
          local args = {
            'log',
            '--color=never',
            '--no-graph',
            '--template=' .. template,
          }
          if opts.reversed then
            table.insert(args, '--reversed')
          end
          vim.list_extend(args, opts.args or {})
          return require('snacks.picker.source.proc').proc({
            opts,
            {
              cmd = cmd,
              args = args,
              cwd = cwd,
              ---@param item snacks.picker.finder.Item
              transform = function(item)
                local data = vim.split(item.text, '\0')
                item.cwd = cwd
                item.change_id_prefix = data[1]
                item.change_id = data[2]
                item.date = data[3]
                item.commit = data[4]
                item.description = data[5]
              end,
            },
          }, ctx)
        end,
        format = function(item)
          local ret = {} ---@type snacks.picker.Highlight[]
          table.insert(ret, { item.change_id_prefix, 'SnacksPickerGitCommit' })
          table.insert(ret, { item.change_id:sub(#item.change_id_prefix + 1), 'SnacksPickerDimmed' })
          table.insert(ret, { ' ' })
          table.insert(ret, { item.date, 'SnacksPickerGitDate' })
          table.insert(ret, { ' ' })
          table.insert(ret, { item.commit, 'SnacksPickerGitStatusModified' })
          table.insert(ret, { ' ' })
          local desc = item.description ---@type string
          local desc_hl = 'SnacksPickerGitMsg'
          if desc == 'root()' then
            desc_hl = 'SnacksPickerGitStatusStaged'
          end
          if desc == '(no description set)' then
            desc_hl = 'SnacksPickerDimmed'
          end
          -- Highlight description
          -- See https://github.com/folke/snacks.nvim/blob/bc0630e43be5699bb94dadc302c0d21615421d93/lua/snacks/picker/format.lua#L179-L204
          local type, scope, breaking, body = desc:match '^(%S+)%s*(%(.-%))(!?):%s*(.*)$'
          if not type then
            type, breaking, body = desc:match '^(%S+)(!?):%s*(.*)$'
          end
          if type and body then
            local dimmed = vim.tbl_contains({ 'chore', 'bot', 'build', 'ci', 'style', 'test' }, type)
            desc_hl = dimmed and 'SnacksPickerDimmed' or 'SnacksPickerGitMsg'
            table.insert(ret, { type, breaking ~= '' and 'SnacksPickerGitBreaking' or dimmed and 'SnacksPickerBold' or 'SnacksPickerGitType' })
            if scope and scope ~= '' then
              table.insert(ret, { scope, 'SnacksPickerGitScope' })
            end
            if breaking ~= '' then
              table.insert(ret, { '!', 'SnacksPickerGitBreaking' })
            end
            table.insert(ret, { ':', 'SnacksPickerDelim' })
            table.insert(ret, { ' ' })
            desc = body
          end
          table.insert(ret, { desc, desc_hl })
          Snacks.picker.highlight.markdown(ret)
          Snacks.picker.highlight.highlight(ret, { ['#%d+'] = 'SnacksPickerGitIssue' })
          return ret
        end,
        preview = function(ctx)
          local M = require 'snacks.picker.preview'
          local cmd = { 'jj', 'log', '-r=' .. ctx.item.change_id }
          local preview_opts = vim.tbl_deep_extend('keep', ctx.picker.opts.previewers.jj or {}, {
            delta = false,
          })
          if preview_opts.delta then
            -- TIP: Disable noisy warning
            -- jj config set --user 'merge-tools.delta.diff-expected-exit-codes' '[0, 1]'
            table.insert(cmd, '--tool=delta')
          else
            table.insert(cmd, '--git')
          end
          M.cmd(cmd, ctx)
        end,
        confirm = function(picker, item)
          picker:close()
          local target = item.change_id
          vim.system({ 'jj', 'edit', target }, { cwd = item.cwd }, function(sys)
            if sys.code == 0 then
              Snacks.notify.info('Edit ' .. target, { title = 'Snacks Picker' })
            else
              Snacks.notify.error(sys.stderr)
            end
          end)
        end,
        sort = { fields = { 'score:desc', 'idx' } },
      },