From ba89b73127ad9a88cfcdb0aa15cb153f4026d7a2 Mon Sep 17 00:00:00 2001
From: Brian Mayo <ioprotium@gmail.com>
Date: Tue, 21 Nov 2023 18:03:10 +0000
Subject: [PATCH 1/6] feat: add formatting options as a list

---
 lua/diffview/config.lua                       | 116 ++++-----
 .../scene/views/file_history/render.lua       | 222 ++++++++++--------
 .../unit/file_history_commit_format_spec.lua  | 152 ++++++++++++
 3 files changed, 325 insertions(+), 165 deletions(-)
 create mode 100644 lua/diffview/tests/unit/file_history_commit_format_spec.lua

diff --git a/lua/diffview/config.lua b/lua/diffview/config.lua
index 86922fe1..734c3205 100644
--- a/lua/diffview/config.lua
+++ b/lua/diffview/config.lua
@@ -96,6 +96,16 @@ M.defaults = {
         multi_file = {},
       },
     },
+    commit_format = {
+      'status',
+      'stats',
+      'hash',
+      'reflog',
+      'ref',
+      'subject',
+      'author',
+      'date',
+    },
     win_config = {
       position = "bottom",
       height = 16,
@@ -334,9 +344,7 @@ M.log_option_defaults = {
 
 ---@return DiffviewConfig
 function M.get_config()
-  if not setup_done then
-    M.setup()
-  end
+  if not setup_done then M.setup() end
 
   return M._config
 end
@@ -349,7 +357,7 @@ function M.get_log_options(single_file, t, vcs)
   local log_options
 
   if single_file then
-    log_options =  M._config.file_history_panel.log_options[vcs].single_file
+    log_options = M._config.file_history_panel.log_options[vcs].single_file
   else
     log_options = M._config.file_history_panel.log_options[vcs].multi_file
   end
@@ -358,9 +366,7 @@ function M.get_log_options(single_file, t, vcs)
     log_options = vim.tbl_extend("force", log_options, t)
 
     for k, _ in pairs(log_options) do
-      if t[k] == "" then
-        log_options[k] = nil
-      end
+      if t[k] == "" then log_options[k] = nil end
     end
   end
 
@@ -409,9 +415,7 @@ end
 
 function M.find_option_keymap(t)
   for _, mapping in ipairs(t) do
-    if mapping[3] and mapping[3] == actions.options then
-      return mapping
-    end
+    if mapping[3] and mapping[3] == actions.options then return mapping end
   end
 end
 
@@ -427,9 +431,13 @@ end
 ---@param no_quote? boolean
 ---@return string
 local function fmt_enum(values, no_quote)
-  return table.concat(vim.tbl_map(function(v)
-    return (not no_quote and type(v) == "string") and ("'" .. v .. "'") or v
-  end, values), "|")
+  return table.concat(
+    vim.tbl_map(
+      function(v) return (not no_quote and type(v) == "string") and ("'" .. v .. "'") or v end,
+      values
+    ),
+    "|"
+  )
 end
 
 ---@param ... table
@@ -441,9 +449,7 @@ function M.extend_keymaps(...)
 
   for i = 1, argc do
     local cur = argv[i]
-    if type(cur) == "table" then
-      contexts[#contexts + 1] = { subject = cur, expanded = {} }
-    end
+    if type(cur) == "table" then contexts[#contexts + 1] = { subject = cur, expanded = {} } end
   end
 
   for _, ctx in ipairs(contexts) do
@@ -461,20 +467,13 @@ function M.extend_keymaps(...)
 
     for _, map in ipairs(ctx.subject) do
       for _, mode in ipairs(type(map[1]) == "table" and map[1] or { map[1] }) do
-        ctx.expanded[mode .. " " .. map[2]] = utils.vec_join(
-          mode,
-          map[2],
-          utils.vec_slice(map, 3)
-        )
+        ctx.expanded[mode .. " " .. map[2]] = utils.vec_join(mode, map[2], utils.vec_slice(map, 3))
       end
     end
   end
 
-  local merged = vim.tbl_extend("force", unpack(
-    vim.tbl_map(function(v)
-      return v.expanded
-    end, contexts)
-  ))
+  local merged =
+    vim.tbl_extend("force", unpack(vim.tbl_map(function(v) return v.expanded end, contexts)))
 
   return vim.tbl_values(merged)
 end
@@ -482,11 +481,7 @@ end
 function M.setup(user_config)
   user_config = user_config or {}
 
-  M._config = vim.tbl_deep_extend(
-    "force",
-    utils.tbl_deep_clone(M.defaults),
-    user_config
-  )
+  M._config = vim.tbl_deep_extend("force", utils.tbl_deep_clone(M.defaults), user_config)
   ---@type EventEmitter
   M.user_emitter = EventEmitter()
 
@@ -500,15 +495,17 @@ function M.setup(user_config)
   local old_win_config_spec = { "position", "width", "height" }
   for _, panel_name in ipairs({ "file_panel", "file_history_panel" }) do
     local panel_config = M._config[panel_name]
-      ---@cast panel_config table
+    ---@cast panel_config table
     local notified = false
 
     for _, option in ipairs(old_win_config_spec) do
       if panel_config[option] ~= nil then
         if not notified then
           utils.warn(
-            ("'%s.{%s}' has been deprecated. See ':h diffview.changelog-136'.")
-            :format(panel_name, fmt_enum(old_win_config_spec, true))
+            ("'%s.{%s}' has been deprecated. See ':h diffview.changelog-136'."):format(
+              panel_name,
+              fmt_enum(old_win_config_spec, true)
+            )
           )
           notified = true
         end
@@ -533,7 +530,9 @@ function M.setup(user_config)
     }
     for _, name in ipairs(top_options) do
       if user_log_options[name] ~= nil then
-        utils.warn("Global config of 'file_panel.log_options' has been deprecated. See ':h diffview.changelog-271'.")
+        utils.warn(
+          "Global config of 'file_panel.log_options' has been deprecated. See ':h diffview.changelog-271'."
+        )
       end
       break
     end
@@ -549,8 +548,9 @@ function M.setup(user_config)
     for _, name in ipairs(option_names) do
       if user_log_options[name] ~= nil then
         utils.warn(
-          ("'file_history_panel.log_options.{%s}' has been deprecated. See ':h diffview.changelog-151'.")
-          :format(fmt_enum(option_names, true))
+          ("'file_history_panel.log_options.{%s}' has been deprecated. See ':h diffview.changelog-151'."):format(
+            fmt_enum(option_names, true)
+          )
         )
         break
       end
@@ -559,9 +559,7 @@ function M.setup(user_config)
 
   --#endregion
 
-  if #M._config.git_cmd == 0 then
-    M._config.git_cmd = M.defaults.git_cmd
-  end
+  if #M._config.git_cmd == 0 then M._config.git_cmd = M.defaults.git_cmd end
 
   do
     -- Validate layouts
@@ -573,7 +571,7 @@ function M.setup(user_config)
       "diff3_vertical",
       "diff3_mixed",
       "diff4_mixed",
-      -1
+      -1,
     }
     local valid_layouts = {
       default = standard_layouts,
@@ -583,11 +581,13 @@ function M.setup(user_config)
 
     for _, kind in ipairs(vim.tbl_keys(valid_layouts)) do
       if not vim.tbl_contains(valid_layouts[kind], view[kind].layout) then
-        utils.err(("Invalid layout name '%s' for 'view.%s'! Must be one of (%s)."):format(
-          view[kind].layout,
-          kind,
-          fmt_enum(valid_layouts[kind])
-        ))
+        utils.err(
+          ("Invalid layout name '%s' for 'view.%s'! Must be one of (%s)."):format(
+            view[kind].layout,
+            kind,
+            fmt_enum(valid_layouts[kind])
+          )
+        )
         view[kind].layout = M.defaults.view[kind].layout
       end
     end
@@ -596,24 +596,16 @@ function M.setup(user_config)
   for _, name in ipairs({ "single_file", "multi_file" }) do
     for _, vcs in ipairs({ "git", "hg" }) do
       local t = M._config.file_history_panel.log_options[vcs]
-      t[name] = vim.tbl_extend(
-        "force",
-        M.log_option_defaults[vcs],
-        t[name]
-      )
+      t[name] = vim.tbl_extend("force", M.log_option_defaults[vcs], t[name])
       for k, _ in pairs(t[name]) do
-        if t[name][k] == "" then
-          t[name][k] = nil
-        end
+        if t[name][k] == "" then t[name][k] = nil end
       end
     end
   end
 
   for event, callback in pairs(M._config.hooks) do
     if type(callback) == "function" then
-      M.user_emitter:on(event, function (_, ...)
-        callback(...)
-      end)
+      M.user_emitter:on(event, function(_, ...) callback(...) end)
     end
   end
 
@@ -630,10 +622,8 @@ function M.setup(user_config)
   -- Merge default and user keymaps
   for name, keymap in pairs(M._config.keymaps) do
     if type(name) == "string" and type(keymap) == "table" then
-      M._config.keymaps[name] = M.extend_keymaps(
-        keymap,
-        utils.tbl_access(user_config, { "keymaps", name }) or {}
-      )
+      M._config.keymaps[name] =
+        M.extend_keymaps(keymap, utils.tbl_access(user_config, { "keymaps", name }) or {})
     end
   end
 
@@ -642,9 +632,7 @@ function M.setup(user_config)
     if type(name) == "string" and type(keymaps) == "table" then
       for i = #keymaps, 1, -1 do
         local v = keymaps[i]
-        if type(v) == "table" and not v[3] then
-          table.remove(keymaps, i)
-        end
+        if type(v) == "table" and not v[3] then table.remove(keymaps, i) end
       end
     end
   end
diff --git a/lua/diffview/scene/views/file_history/render.lua b/lua/diffview/scene/views/file_history/render.lua
index 24b13970..7fc88540 100644
--- a/lua/diffview/scene/views/file_history/render.lua
+++ b/lua/diffview/scene/views/file_history/render.lua
@@ -10,6 +10,103 @@ local pl = utils.path
 
 local cache = setmetatable({}, { __mode = "k" })
 
+local formatters = {
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  status = function(comp, entry, _)
+    if entry.status then
+      comp:add_text(entry.status, hl.get_git_hl(entry.status))
+    else
+      comp:add_text("-", "DiffviewNonText")
+    end
+  end,
+
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  files = function(comp, entry, params)
+    if entry.single_file then return end
+
+    local s_num_files = tostring(params.max_num_files)
+
+    if entry.nulled then
+      comp:add_text(utils.str_center_pad("empty", #s_num_files + 7), "DiffviewFilePanelCounter")
+    else
+      comp:add_text(
+        fmt(
+          " %s file%s",
+          utils.str_left_pad(tostring(#entry.files), #s_num_files),
+          #entry.files > 1 and "s" or " "
+        ),
+        "DiffviewFilePanelCounter"
+      )
+    end
+  end,
+
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  hash = function(comp, entry, _)
+    if entry.commit.hash then comp:add_text(" " .. entry.commit.hash:sub(1, 8), "DiffviewHash") end
+  end,
+
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  stats = function(comp, entry, params)
+    if params.max_len_stats == -1 then return end
+
+    local adds = { "-", "DiffviewNonText" }
+    local dels = { "-", "DiffviewNonText" }
+
+    if entry.stats and entry.stats.additions then
+      adds = { tostring(entry.stats.additions), "DiffviewFilePanelInsertions" }
+    end
+
+    if entry.stats and entry.stats.deletions then
+      dels = { tostring(entry.stats.deletions), "DiffviewFilePanelDeletions" }
+    end
+
+    comp:add_text(" | ", "DiffviewNonText")
+    comp:add_text(unpack(adds))
+    comp:add_text(string.rep(" ", params.max_len_stats - (#adds[1] + #dels[1])))
+    comp:add_text(unpack(dels))
+    comp:add_text(" |", "DiffviewNonText")
+  end,
+
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  reflog = function(comp, entry, _)
+    local reflog_selector = (entry.commit --[[@as GitCommit ]]).reflog_selector
+    if reflog_selector then
+      comp:add_text((" %s"):format(reflog_selector), "DiffviewReflogSelector")
+    end
+  end,
+
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  ref = function(comp, entry, _)
+    if entry.commit.ref_names then
+      comp:add_text((" (%s)"):format(entry.commit.ref_names), "DiffviewReference")
+    end
+  end,
+
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  subject = function(comp, entry, params)
+    local subject = utils.str_trunc(entry.commit.subject, 72)
+    if subject == "" then subject = "[empty message]" end
+    comp:add_text(
+      " " .. subject,
+      params.panel.cur_item[1] == entry and "DiffviewFilePanelSelected"
+        or "DiffviewFilePanelFileName"
+    )
+  end,
+
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  author = function(comp, entry, _) comp:add_text(" " .. entry.commit.author) end,
+
+  ---@type fun(comp:RenderComponent, entry:LogEntry, params:table)
+  date = function(comp, entry, _)
+    -- 3 months
+    local date = (
+      os.difftime(os.time(), entry.commit.time) > 60 * 60 * 24 * 30 * 3 and entry.commit.iso_date
+      or entry.commit.rel_date
+    )
+    comp:add_text(" " .. date, "DiffviewFilePanelPath")
+  end,
+}
+
 ---@param comp RenderComponent
 ---@param files FileEntry[]
 local function render_files(comp, files)
@@ -35,7 +132,10 @@ local function render_files(comp, files)
         comp:add_text(file.parent_path .. "/", "DiffviewFilePanelPath")
       end
 
-      comp:add_text(file.basename, file.active and "DiffviewFilePanelSelected" or "DiffviewFilePanelFileName")
+      comp:add_text(
+        file.basename,
+        file.active and "DiffviewFilePanelSelected" or "DiffviewFilePanelFileName"
+      )
 
       if file.stats then
         comp:add_text(" " .. file.stats.additions, "DiffviewFilePanelInsertions")
@@ -60,107 +160,38 @@ local function render_entries(panel, parent, entries, updating)
   local max_len_stats = -1
 
   for _, entry in ipairs(entries) do
-    if #entry.files > max_num_files then
-      max_num_files = #entry.files
-    end
+    if #entry.files > max_num_files then max_num_files = #entry.files end
 
     if entry.stats then
       local adds = tostring(entry.stats.additions)
       local dels = tostring(entry.stats.deletions)
       local l = 7
       local w = l - (#adds + #dels)
-      if w < 1 then
-        l = (#adds + #dels) - ((#adds + #dels) % 2) + 2
-      end
+      if w < 1 then l = (#adds + #dels) - ((#adds + #dels) % 2) + 2 end
       max_len_stats = l > max_len_stats and l or max_len_stats
     end
   end
 
   for i, entry in ipairs(entries) do
-    if i > #parent or (updating and i > 128) then
-      break
-    end
+    if i > #parent or (updating and i > 128) then break end
 
     local entry_struct = parent[i]
     local comp = entry_struct.commit.comp
 
     if not entry.single_file then
-      comp:add_text((entry.folded and c.signs.fold_closed or c.signs.fold_open) .. " ", "CursorLineNr")
-    end
-
-    if entry.status then
-      comp:add_text(entry.status, hl.get_git_hl(entry.status))
-    else
-      comp:add_text("-", "DiffviewNonText")
+      comp:add_text(
+        (entry.folded and c.signs.fold_closed or c.signs.fold_open) .. " ",
+        "CursorLineNr"
+      )
     end
 
-    if not entry.single_file then
-      local s_num_files = tostring(max_num_files)
-
-      if entry.nulled then
-        comp:add_text(utils.str_center_pad("empty", #s_num_files + 7), "DiffviewFilePanelCounter")
+    for format in c.file_history_panel.commit_format do
+      local fn = formatters[format]
+      if fn then
+        fn(comp, entry, { max_len_stats, max_num_files, panel })
       else
-        comp:add_text(
-          fmt(
-            " %s file%s",
-            utils.str_left_pad(tostring(#entry.files), #s_num_files),
-            #entry.files > 1 and "s" or " "
-          ),
-          "DiffviewFilePanelCounter"
-        )
-      end
-    end
-
-    if max_len_stats ~= -1 then
-      local adds = { "-", "DiffviewNonText" }
-      local dels = { "-", "DiffviewNonText" }
-
-      if entry.stats and entry.stats.additions then
-        adds = { tostring(entry.stats.additions), "DiffviewFilePanelInsertions" }
+        logger:warn("[format] Unsopported commit format: " .. format)
       end
-
-      if entry.stats and entry.stats.deletions then
-        dels = { tostring(entry.stats.deletions), "DiffviewFilePanelDeletions" }
-      end
-
-      comp:add_text(" | ", "DiffviewNonText")
-      comp:add_text(unpack(adds))
-      comp:add_text(string.rep(" ", max_len_stats - (#adds[1] + #dels[1])))
-      comp:add_text(unpack(dels))
-      comp:add_text(" |", "DiffviewNonText")
-    end
-
-    if entry.commit.hash then
-      comp:add_text(" " .. entry.commit.hash:sub(1, 8), "DiffviewHash")
-    end
-
-    if (entry.commit --[[@as GitCommit ]]).reflog_selector then
-      comp:add_text((" %s"):format((entry.commit --[[@as GitCommit ]]).reflog_selector), "DiffviewReflogSelector")
-    end
-
-    if entry.commit.ref_names then
-      comp:add_text((" (%s)"):format(entry.commit.ref_names), "DiffviewReference")
-    end
-
-    local subject = utils.str_trunc(entry.commit.subject, 72)
-
-    if subject == "" then
-      subject = "[empty message]"
-    end
-
-    comp:add_text(
-      " " .. subject,
-      panel.cur_item[1] == entry and "DiffviewFilePanelSelected" or "DiffviewFilePanelFileName"
-    )
-
-    if entry.commit then
-      -- 3 months
-      local date = (
-        os.difftime(os.time(), entry.commit.time) > 60 * 60 * 24 * 30 * 3
-          and entry.commit.iso_date
-          or entry.commit.rel_date
-      )
-      comp:add_text(" " .. entry.commit.author .. ", " .. date, "DiffviewFilePanelPath")
     end
 
     comp:ln()
@@ -177,27 +208,22 @@ local function prepare_panel_cache(panel)
   local c = {}
   cache[panel] = c
   c.root_path = panel.state.form == "column"
-      and pl:truncate(
-        pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~"),
-        panel:infer_width() - 6
-      )
+      and pl:truncate(pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~"), panel:infer_width() - 6)
     or pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~")
   c.args = table.concat(panel.log_options.single_file.path_args, " ")
 end
 
 return {
+  commit_formatters = formatters,
+
   ---@param panel FileHistoryPanel
   file_history_panel = function(panel)
-    if not panel.render_data then
-      return
-    end
+    if not panel.render_data then return end
 
     perf:reset()
     panel.render_data:clear()
 
-    if not cache[panel] then
-      prepare_panel_cache(panel)
-    end
+    if not cache[panel] then prepare_panel_cache(panel) end
 
     local conf = config.get_config()
     local comp = panel.components.header.comp
@@ -253,9 +279,7 @@ return {
     comp:add_text("File History ", "DiffviewFilePanelTitle")
     comp:add_text("(" .. #panel.entries .. ")", "DiffviewFilePanelCounter")
 
-    if panel.updating then
-      comp:add_text(" (Updating...)", "DiffviewDim1")
-    end
+    if panel.updating then comp:add_text(" (Updating...)", "DiffviewDim1") end
 
     comp:ln()
     perf:lap("header")
@@ -270,9 +294,7 @@ return {
 
   ---@param panel FHOptionPanel
   fh_option_panel = function(panel)
-    if not panel.render_data then
-      return
-    end
+    if not panel.render_data then return end
 
     panel.render_data:clear()
 
@@ -312,7 +334,5 @@ return {
       comp:ln()
     end
   end,
-  clear_cache = function(panel)
-    cache[panel] = nil
-  end,
+  clear_cache = function(panel) cache[panel] = nil end,
 }
diff --git a/lua/diffview/tests/unit/file_history_commit_format_spec.lua b/lua/diffview/tests/unit/file_history_commit_format_spec.lua
new file mode 100644
index 00000000..36e62527
--- /dev/null
+++ b/lua/diffview/tests/unit/file_history_commit_format_spec.lua
@@ -0,0 +1,152 @@
+local helpers = require("diffview.tests.helpers")
+
+local eq, neq = helpers.eq, helpers.neq
+local formatters = require("diffview.scene.views.file_history.render").commit_formatters
+
+-- Windows path standards:
+-- https://learn.microsoft.com/en-us/dotnet/standard/io/file-path-formats
+
+describe("diffview.scenes.views.file_history.render.formatters", function()
+  local renderer = require("diffview.renderer")
+
+  it("status()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    formatters.status(comp, { status = "M" }, {})
+    comp:ln()
+    eq("M", comp.lines[1])
+
+    comp:clear()
+    formatters.status(comp, { status = nil }, {})
+    comp:ln()
+    eq("-", comp.lines[1])
+
+    comp:destroy()
+  end)
+
+  it("files()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    formatters.files(comp, { single_file = false, files = { "a file" } }, { max_num_files = 1 })
+    comp:ln()
+    eq(" 1 file ", comp.lines[1])
+    eq("DiffviewFilePanelCounter", comp.hl[1].group)
+
+    comp:clear()
+    formatters.files(
+      comp,
+      { nulled = true, single_file = false, files = { "a file" } },
+      { max_num_files = 1 }
+    )
+    comp:ln()
+    eq(" empty  ", comp.lines[1])
+
+    comp:clear()
+    formatters.files(comp, { single_file = true }, {})
+    comp:ln()
+    eq("", comp.lines[1])
+
+    comp:destroy()
+  end)
+
+  it("hash()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    formatters.hash(
+      comp,
+      { commit = { hash = "762489b5c8d74bf8bbfb211d49aed686" } },
+      { max_num_files = 1 }
+    )
+    comp:ln()
+    eq(" 762489b5", comp.lines[1])
+    eq("DiffviewHash", comp.hl[1].group)
+
+    comp:destroy()
+  end)
+
+  it("stats()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    formatters.stats(comp, { stats = { additions = 10, deletions = 22 } }, { max_len_stats = 4 })
+    comp:ln()
+    eq(" | 1022 |", comp.lines[1])
+    eq("DiffviewNonText", comp.hl[1].group)
+    eq("DiffviewFilePanelInsertions", comp.hl[2].group)
+    eq("DiffviewFilePanelDeletions", comp.hl[3].group)
+    eq("DiffviewNonText", comp.hl[4].group)
+
+    comp:destroy()
+  end)
+
+  it("reflog()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    formatters.reflog(comp, { commit = { reflog_selector = "reflog" } }, {})
+    comp:ln()
+    eq(" reflog", comp.lines[1])
+    eq("DiffviewReflogSelector", comp.hl[1].group)
+
+    comp:destroy()
+  end)
+
+  it("ref()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    formatters.ref(comp, { commit = { ref_names = "main" } }, {})
+    comp:ln()
+    eq(" (main)", comp.lines[1])
+    eq("DiffviewReference", comp.hl[1].group)
+
+    comp:destroy()
+  end)
+
+  it("subject()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    formatters.subject(
+      comp,
+      { commit = { subject = "refactor: cleanup" } },
+      { panel = { cur_item = { nil } } }
+    )
+    comp:ln()
+    eq(" refactor: cleanup", comp.lines[1])
+    eq("DiffviewFilePanelFileName", comp.hl[1].group)
+
+    comp:clear()
+    formatters.subject(comp, { commit = { subject = "" } }, { panel = { cur_item = { nil } } })
+    comp:ln()
+    eq(" [empty message]", comp.lines[1])
+    eq("DiffviewFilePanelFileName", comp.hl[1].group)
+
+    comp:clear()
+    local entry = { commit = { subject = "fix #1111" } }
+    formatters.subject(comp, entry, { panel = { cur_item = { entry } } })
+    comp:ln()
+    eq(" fix #1111", comp.lines[1])
+    eq("DiffviewFilePanelSelected", comp.hl[1].group)
+
+    comp:destroy()
+  end)
+
+  it("author()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    formatters.author(comp, { commit = { author = "Dale Cooper" } }, {})
+    comp:ln()
+    eq(" Dale Cooper", comp.lines[1])
+
+    comp:destroy()
+  end)
+
+  it("date()", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    local time = os.time({ year = 2023, month = 1, day = 1 })
+    local iso = os.date("%FT%TZ", time)
+    formatters.date(comp, { commit = { time = time, iso_date = iso } }, {})
+    comp:ln()
+    eq(" " .. iso, comp.lines[1])
+
+    comp:destroy()
+  end)
+end)

From 1d133f28f1441750640a70a31df01cbe96155907 Mon Sep 17 00:00:00 2001
From: Brian Mayo <ioprotium@gmail.com>
Date: Tue, 21 Nov 2023 18:20:09 +0000
Subject: [PATCH 2/6] docs: default config for file history pannel commit
 format

---
 doc/diffview_defaults.txt | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/doc/diffview_defaults.txt b/doc/diffview_defaults.txt
index 1a89b468..2b55f00f 100644
--- a/doc/diffview_defaults.txt
+++ b/doc/diffview_defaults.txt
@@ -21,7 +21,7 @@ DEFAULT CONFIG                                  *diffview.defaults*
     },
     view = {
       -- Configure the layout and behavior of different types of views.
-      -- Available layouts: 
+      -- Available layouts:
       --  'diff1_plain'
       --    |'diff2_horizontal'
       --    |'diff2_vertical'
@@ -74,6 +74,16 @@ DEFAULT CONFIG                                  *diffview.defaults*
           multi_file = {},
         },
       },
+      commit_format = {
+        'status',
+        'stats',
+        'hash',
+        'reflog',
+        'ref',
+        'subject',
+        'author',
+        'date',
+      },
       win_config = {    -- See |diffview-config-win_config|
         position = "bottom",
         height = 16,

From c45146c6f6da24d0a9db46a405dd8bc4bfc487c8 Mon Sep 17 00:00:00 2001
From: Brian Mayo <ioprotium@gmail.com>
Date: Tue, 21 Nov 2023 19:38:16 +0000
Subject: [PATCH 3/6] test: all format components

---
 .../unit/file_history_commit_format_spec.lua  | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/lua/diffview/tests/unit/file_history_commit_format_spec.lua b/lua/diffview/tests/unit/file_history_commit_format_spec.lua
index 36e62527..89f37281 100644
--- a/lua/diffview/tests/unit/file_history_commit_format_spec.lua
+++ b/lua/diffview/tests/unit/file_history_commit_format_spec.lua
@@ -1,4 +1,5 @@
 local helpers = require("diffview.tests.helpers")
+local config = require("diffview.config")
 
 local eq, neq = helpers.eq, helpers.neq
 local formatters = require("diffview.scene.views.file_history.render").commit_formatters
@@ -149,4 +150,39 @@ describe("diffview.scenes.views.file_history.render.formatters", function()
 
     comp:destroy()
   end)
+
+  it("default config format", function()
+    --- @type RenderComponent
+    local comp = renderer.RenderComponent.create_static_component(nil)
+    local c = config.get_config()
+    local time = os.time({ year = 2023, month = 1, day = 1 })
+    local iso = os.date("%FT%TZ", time)
+    local entry = {
+      stats = { additions = 121, deletions = 101 },
+      status = "M",
+      commit = {
+        time = time,
+        iso_date = iso,
+        hash = "ba89b7310101",
+        subject = "fix #1",
+        author = "Dale Cooper",
+      },
+    }
+
+    local params = {
+      panel = { cur_item = { nil } },
+      max_num_files = 1,
+      max_len_stats = 7,
+    }
+
+    for _, f in ipairs(c.file_history_panel.commit_format) do
+      formatters[f](comp, entry, params)
+    end
+
+    comp:ln()
+    local expected = string.format("M | 121 101 | ba89b731 fix #1 Dale Cooper %s", iso)
+    eq(expected, table.concat(comp.lines, " "))
+
+    comp:destroy()
+  end)
 end)

From 53d2539fc777c49dae562516605bf75eec107ec4 Mon Sep 17 00:00:00 2001
From: Brian Mayo <ioprotium@gmail.com>
Date: Sun, 3 Dec 2023 01:46:40 +0000
Subject: [PATCH 4/6] revert formatting

---
 lua/diffview/config.lua                       | 102 +++++++++++-------
 .../scene/views/file_history/render.lua       |  47 ++++----
 2 files changed, 91 insertions(+), 58 deletions(-)

diff --git a/lua/diffview/config.lua b/lua/diffview/config.lua
index 734c3205..7bfe1169 100644
--- a/lua/diffview/config.lua
+++ b/lua/diffview/config.lua
@@ -344,7 +344,9 @@ M.log_option_defaults = {
 
 ---@return DiffviewConfig
 function M.get_config()
-  if not setup_done then M.setup() end
+  if not setup_done then
+    M.setup()
+  end
 
   return M._config
 end
@@ -366,7 +368,9 @@ function M.get_log_options(single_file, t, vcs)
     log_options = vim.tbl_extend("force", log_options, t)
 
     for k, _ in pairs(log_options) do
-      if t[k] == "" then log_options[k] = nil end
+      if t[k] == "" then
+        log_options[k] = nil
+      end
     end
   end
 
@@ -415,7 +419,9 @@ end
 
 function M.find_option_keymap(t)
   for _, mapping in ipairs(t) do
-    if mapping[3] and mapping[3] == actions.options then return mapping end
+    if mapping[3] and mapping[3] == actions.options then
+      return mapping
+    end
   end
 end
 
@@ -431,13 +437,9 @@ end
 ---@param no_quote? boolean
 ---@return string
 local function fmt_enum(values, no_quote)
-  return table.concat(
-    vim.tbl_map(
-      function(v) return (not no_quote and type(v) == "string") and ("'" .. v .. "'") or v end,
-      values
-    ),
-    "|"
-  )
+  return table.concat(vim.tbl_map(function(v)
+    return (not no_quote and type(v) == "string") and ("'" .. v .. "'") or v
+  end, values), "|")
 end
 
 ---@param ... table
@@ -449,7 +451,9 @@ function M.extend_keymaps(...)
 
   for i = 1, argc do
     local cur = argv[i]
-    if type(cur) == "table" then contexts[#contexts + 1] = { subject = cur, expanded = {} } end
+    if type(cur) == "table" then
+      contexts[#contexts + 1] = { subject = cur, expanded = {} }
+    end
   end
 
   for _, ctx in ipairs(contexts) do
@@ -467,13 +471,20 @@ function M.extend_keymaps(...)
 
     for _, map in ipairs(ctx.subject) do
       for _, mode in ipairs(type(map[1]) == "table" and map[1] or { map[1] }) do
-        ctx.expanded[mode .. " " .. map[2]] = utils.vec_join(mode, map[2], utils.vec_slice(map, 3))
+        ctx.expanded[mode .. " " .. map[2]] = utils.vec_join(
+          mode,
+          map[2],
+          utils.vec_slice(map, 3)
+        )
       end
     end
   end
 
-  local merged =
-    vim.tbl_extend("force", unpack(vim.tbl_map(function(v) return v.expanded end, contexts)))
+  local merged = vim.tbl_extend("force", unpack(
+      vim.tbl_map(function(v)
+        return v.expanded
+      end, contexts)
+  ))
 
   return vim.tbl_values(merged)
 end
@@ -481,7 +492,11 @@ end
 function M.setup(user_config)
   user_config = user_config or {}
 
-  M._config = vim.tbl_deep_extend("force", utils.tbl_deep_clone(M.defaults), user_config)
+  M._config = vim.tbl_deep_extend(
+    "force",
+    utils.tbl_deep_clone(M.defaults),
+    user_config
+  )
   ---@type EventEmitter
   M.user_emitter = EventEmitter()
 
@@ -502,10 +517,8 @@ function M.setup(user_config)
       if panel_config[option] ~= nil then
         if not notified then
           utils.warn(
-            ("'%s.{%s}' has been deprecated. See ':h diffview.changelog-136'."):format(
-              panel_name,
-              fmt_enum(old_win_config_spec, true)
-            )
+            ("'%s.{%s}' has been deprecated. See ':h diffview.changelog-136'.")
+            :format( panel_name, fmt_enum(old_win_config_spec, true))
           )
           notified = true
         end
@@ -530,9 +543,7 @@ function M.setup(user_config)
     }
     for _, name in ipairs(top_options) do
       if user_log_options[name] ~= nil then
-        utils.warn(
-          "Global config of 'file_panel.log_options' has been deprecated. See ':h diffview.changelog-271'."
-        )
+        utils.warn( "Global config of 'file_panel.log_options' has been deprecated. See ':h diffview.changelog-271'.")
       end
       break
     end
@@ -548,9 +559,8 @@ function M.setup(user_config)
     for _, name in ipairs(option_names) do
       if user_log_options[name] ~= nil then
         utils.warn(
-          ("'file_history_panel.log_options.{%s}' has been deprecated. See ':h diffview.changelog-151'."):format(
-            fmt_enum(option_names, true)
-          )
+          ("'file_history_panel.log_options.{%s}' has been deprecated. See ':h diffview.changelog-151'.")
+          :format( fmt_enum(option_names, true))
         )
         break
       end
@@ -559,7 +569,9 @@ function M.setup(user_config)
 
   --#endregion
 
-  if #M._config.git_cmd == 0 then M._config.git_cmd = M.defaults.git_cmd end
+  if #M._config.git_cmd == 0 then
+    M._config.git_cmd = M.defaults.git_cmd
+  end
 
   do
     -- Validate layouts
@@ -571,7 +583,7 @@ function M.setup(user_config)
       "diff3_vertical",
       "diff3_mixed",
       "diff4_mixed",
-      -1,
+      -1
     }
     local valid_layouts = {
       default = standard_layouts,
@@ -581,13 +593,11 @@ function M.setup(user_config)
 
     for _, kind in ipairs(vim.tbl_keys(valid_layouts)) do
       if not vim.tbl_contains(valid_layouts[kind], view[kind].layout) then
-        utils.err(
-          ("Invalid layout name '%s' for 'view.%s'! Must be one of (%s)."):format(
-            view[kind].layout,
-            kind,
-            fmt_enum(valid_layouts[kind])
-          )
-        )
+        utils.err( ("Invalid layout name '%s' for 'view.%s'! Must be one of (%s)."):format(
+          view[kind].layout,
+          kind,
+          fmt_enum(valid_layouts[kind])
+        ))
         view[kind].layout = M.defaults.view[kind].layout
       end
     end
@@ -596,16 +606,24 @@ function M.setup(user_config)
   for _, name in ipairs({ "single_file", "multi_file" }) do
     for _, vcs in ipairs({ "git", "hg" }) do
       local t = M._config.file_history_panel.log_options[vcs]
-      t[name] = vim.tbl_extend("force", M.log_option_defaults[vcs], t[name])
+      t[name] = vim.tbl_extend(
+        "force",
+        M.log_option_defaults[vcs],
+        t[name]
+      )
       for k, _ in pairs(t[name]) do
-        if t[name][k] == "" then t[name][k] = nil end
+        if t[name][k] == ""
+          then t[name][k] = nil
+        end
       end
     end
   end
 
   for event, callback in pairs(M._config.hooks) do
     if type(callback) == "function" then
-      M.user_emitter:on(event, function(_, ...) callback(...) end)
+      M.user_emitter:on(event, function(_, ...)
+        callback(...)
+      end)
     end
   end
 
@@ -622,8 +640,10 @@ function M.setup(user_config)
   -- Merge default and user keymaps
   for name, keymap in pairs(M._config.keymaps) do
     if type(name) == "string" and type(keymap) == "table" then
-      M._config.keymaps[name] =
-        M.extend_keymaps(keymap, utils.tbl_access(user_config, { "keymaps", name }) or {})
+      M._config.keymaps[name] = M.extend_keymaps(
+        keymap,
+        utils.tbl_access(user_config, { "keymaps", name }) or {}
+      )
     end
   end
 
@@ -632,7 +652,9 @@ function M.setup(user_config)
     if type(name) == "string" and type(keymaps) == "table" then
       for i = #keymaps, 1, -1 do
         local v = keymaps[i]
-        if type(v) == "table" and not v[3] then table.remove(keymaps, i) end
+        if type(v) == "table" and not v[3] then
+          table.remove(keymaps, i)
+        end
       end
     end
   end
diff --git a/lua/diffview/scene/views/file_history/render.lua b/lua/diffview/scene/views/file_history/render.lua
index 7fc88540..1652df35 100644
--- a/lua/diffview/scene/views/file_history/render.lua
+++ b/lua/diffview/scene/views/file_history/render.lua
@@ -89,7 +89,7 @@ local formatters = {
     comp:add_text(
       " " .. subject,
       params.panel.cur_item[1] == entry and "DiffviewFilePanelSelected"
-        or "DiffviewFilePanelFileName"
+      or "DiffviewFilePanelFileName"
     )
   end,
 
@@ -132,10 +132,7 @@ local function render_files(comp, files)
         comp:add_text(file.parent_path .. "/", "DiffviewFilePanelPath")
       end
 
-      comp:add_text(
-        file.basename,
-        file.active and "DiffviewFilePanelSelected" or "DiffviewFilePanelFileName"
-      )
+      comp:add_text(file.basename, file.active and "DiffviewFilePanelSelected" or "DiffviewFilePanelFileName")
 
       if file.stats then
         comp:add_text(" " .. file.stats.additions, "DiffviewFilePanelInsertions")
@@ -160,7 +157,9 @@ local function render_entries(panel, parent, entries, updating)
   local max_len_stats = -1
 
   for _, entry in ipairs(entries) do
-    if #entry.files > max_num_files then max_num_files = #entry.files end
+    if #entry.files > max_num_files then
+      max_num_files = #entry.files
+    end
 
     if entry.stats then
       local adds = tostring(entry.stats.additions)
@@ -173,16 +172,15 @@ local function render_entries(panel, parent, entries, updating)
   end
 
   for i, entry in ipairs(entries) do
-    if i > #parent or (updating and i > 128) then break end
+    if i > #parent or (updating and i > 128) then
+      break
+    end
 
     local entry_struct = parent[i]
     local comp = entry_struct.commit.comp
 
     if not entry.single_file then
-      comp:add_text(
-        (entry.folded and c.signs.fold_closed or c.signs.fold_open) .. " ",
-        "CursorLineNr"
-      )
+      comp:add_text((entry.folded and c.signs.fold_closed or c.signs.fold_open) .. " ", "CursorLineNr")
     end
 
     for format in c.file_history_panel.commit_format do
@@ -208,8 +206,11 @@ local function prepare_panel_cache(panel)
   local c = {}
   cache[panel] = c
   c.root_path = panel.state.form == "column"
-      and pl:truncate(pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~"), panel:infer_width() - 6)
-    or pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~")
+      and pl:truncate(
+        pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~"),
+        panel:infer_width() - 6
+      )
+      or pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~")
   c.args = table.concat(panel.log_options.single_file.path_args, " ")
 end
 
@@ -218,12 +219,16 @@ return {
 
   ---@param panel FileHistoryPanel
   file_history_panel = function(panel)
-    if not panel.render_data then return end
+    if not panel.render_data then
+      return
+    end
 
     perf:reset()
     panel.render_data:clear()
 
-    if not cache[panel] then prepare_panel_cache(panel) end
+    if not cache[panel] then
+      prepare_panel_cache(panel)
+    end
 
     local conf = config.get_config()
     local comp = panel.components.header.comp
@@ -279,7 +284,9 @@ return {
     comp:add_text("File History ", "DiffviewFilePanelTitle")
     comp:add_text("(" .. #panel.entries .. ")", "DiffviewFilePanelCounter")
 
-    if panel.updating then comp:add_text(" (Updating...)", "DiffviewDim1") end
+    if panel.updating then
+      comp:add_text(" (Updating...)", "DiffviewDim1")
+    end
 
     comp:ln()
     perf:lap("header")
@@ -294,7 +301,9 @@ return {
 
   ---@param panel FHOptionPanel
   fh_option_panel = function(panel)
-    if not panel.render_data then return end
+    if not panel.render_data then
+      return
+    end
 
     panel.render_data:clear()
 
@@ -334,5 +343,7 @@ return {
       comp:ln()
     end
   end,
-  clear_cache = function(panel) cache[panel] = nil end,
+  clear_cache = function(panel)
+    cache[panel] = nil
+  end,
 }

From b39df42a91e34f6a061c144ec9ea63d8f666d35d Mon Sep 17 00:00:00 2001
From: Brian Mayo <ioprotium@gmail.com>
Date: Sun, 3 Dec 2023 01:58:40 +0000
Subject: [PATCH 5/6] test: monkey patch os.difftime to cover commit relative
 date

---
 .../tests/unit/file_history_commit_format_spec.lua   | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/lua/diffview/tests/unit/file_history_commit_format_spec.lua b/lua/diffview/tests/unit/file_history_commit_format_spec.lua
index 89f37281..b51d3cfa 100644
--- a/lua/diffview/tests/unit/file_history_commit_format_spec.lua
+++ b/lua/diffview/tests/unit/file_history_commit_format_spec.lua
@@ -148,7 +148,19 @@ describe("diffview.scenes.views.file_history.render.formatters", function()
     comp:ln()
     eq(" " .. iso, comp.lines[1])
 
+    comp:clear()
+    local tmp_diff_time = os.difftime
+    os.difftime = function()
+      return 1
+    end
+
+    formatters.date(comp, { commit = { time = time, iso_date = iso, rel_date = '1 day' } }, {})
+    comp:ln()
+    eq(" 1 day", comp.lines[1])
+
     comp:destroy()
+
+    os.difftime = tmp_diff_time
   end)
 
   it("default config format", function()

From 065435b5dfa113a9affc94bb2fab77929a040b74 Mon Sep 17 00:00:00 2001
From: Brian Mayo <ioprotium@gmail.com>
Date: Sun, 3 Dec 2023 02:02:59 +0000
Subject: [PATCH 6/6] style format

---
 lua/diffview/config.lua                       | 20 +++++++++----------
 .../scene/views/file_history/render.lua       |  6 ++++--
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/lua/diffview/config.lua b/lua/diffview/config.lua
index 7bfe1169..195cf329 100644
--- a/lua/diffview/config.lua
+++ b/lua/diffview/config.lua
@@ -481,9 +481,9 @@ function M.extend_keymaps(...)
   end
 
   local merged = vim.tbl_extend("force", unpack(
-      vim.tbl_map(function(v)
-        return v.expanded
-      end, contexts)
+    vim.tbl_map(function(v)
+      return v.expanded
+    end, contexts)
   ))
 
   return vim.tbl_values(merged)
@@ -518,7 +518,7 @@ function M.setup(user_config)
         if not notified then
           utils.warn(
             ("'%s.{%s}' has been deprecated. See ':h diffview.changelog-136'.")
-            :format( panel_name, fmt_enum(old_win_config_spec, true))
+            :format(panel_name, fmt_enum(old_win_config_spec, true))
           )
           notified = true
         end
@@ -543,7 +543,7 @@ function M.setup(user_config)
     }
     for _, name in ipairs(top_options) do
       if user_log_options[name] ~= nil then
-        utils.warn( "Global config of 'file_panel.log_options' has been deprecated. See ':h diffview.changelog-271'.")
+        utils.warn("Global config of 'file_panel.log_options' has been deprecated. See ':h diffview.changelog-271'.")
       end
       break
     end
@@ -560,7 +560,7 @@ function M.setup(user_config)
       if user_log_options[name] ~= nil then
         utils.warn(
           ("'file_history_panel.log_options.{%s}' has been deprecated. See ':h diffview.changelog-151'.")
-          :format( fmt_enum(option_names, true))
+          :format(fmt_enum(option_names, true))
         )
         break
       end
@@ -593,7 +593,7 @@ function M.setup(user_config)
 
     for _, kind in ipairs(vim.tbl_keys(valid_layouts)) do
       if not vim.tbl_contains(valid_layouts[kind], view[kind].layout) then
-        utils.err( ("Invalid layout name '%s' for 'view.%s'! Must be one of (%s)."):format(
+        utils.err(("Invalid layout name '%s' for 'view.%s'! Must be one of (%s)."):format(
           view[kind].layout,
           kind,
           fmt_enum(valid_layouts[kind])
@@ -612,8 +612,8 @@ function M.setup(user_config)
         t[name]
       )
       for k, _ in pairs(t[name]) do
-        if t[name][k] == ""
-          then t[name][k] = nil
+        if t[name][k] == "" then
+          t[name][k] = nil
         end
       end
     end
@@ -621,7 +621,7 @@ function M.setup(user_config)
 
   for event, callback in pairs(M._config.hooks) do
     if type(callback) == "function" then
-      M.user_emitter:on(event, function(_, ...)
+      M.user_emitter:on(event, function (_, ...)
         callback(...)
       end)
     end
diff --git a/lua/diffview/scene/views/file_history/render.lua b/lua/diffview/scene/views/file_history/render.lua
index 1652df35..5620c321 100644
--- a/lua/diffview/scene/views/file_history/render.lua
+++ b/lua/diffview/scene/views/file_history/render.lua
@@ -166,7 +166,9 @@ local function render_entries(panel, parent, entries, updating)
       local dels = tostring(entry.stats.deletions)
       local l = 7
       local w = l - (#adds + #dels)
-      if w < 1 then l = (#adds + #dels) - ((#adds + #dels) % 2) + 2 end
+      if w < 1 then
+        l = (#adds + #dels) - ((#adds + #dels) % 2) + 2
+      end
       max_len_stats = l > max_len_stats and l or max_len_stats
     end
   end
@@ -210,7 +212,7 @@ local function prepare_panel_cache(panel)
         pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~"),
         panel:infer_width() - 6
       )
-      or pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~")
+    or pl:vim_fnamemodify(panel.adapter.ctx.toplevel, ":~")
   c.args = table.concat(panel.log_options.single_file.path_args, " ")
 end