refactor(wezterm): deduplicate format-tab-title event calls

dots/.config/wezterm/config/tabbar.lua

@@ -13,6 +13,10 @@ local edges = {
     },
 }
 
+-- This function returns the suggested title for a tab.
+-- It prefers the title that was set via `tab:set_title()`
+-- or `wezterm cli set-tab-title`, but falls back to the
+-- title of the active pane in that tab.
 ---@diagnostic disable-next-line: unused-local
 wezterm.on("format-tab-title", function(tab, tabs, panes, config, hover, max_width)
     log.debug("received event", { prefix = "format-tab-title", ignore_result = true })
@@ -36,6 +40,10 @@ wezterm.on("format-tab-title", function(tab, tabs, panes, config, hover, max_wid
 
     local title = " " .. wezterm.truncate_right(tab_title(tab), max_width - 2) .. " "
 
+    if title:match("^%s+$") then
+        title = " N/A "
+    end
+
     if tab.is_active then
         bg = color_names.kanagawa.sumiInk0
         fg = color_names.kanagawa.oniViolet

dots/.config/wezterm/config/theme/colors.lua

@@ -138,50 +138,4 @@ local edges = {
     },
 }
 
----@diagnostic disable-next-line: unused-local
-wezterm.on("format-tab-title", function(tab, tabs, panes, config, hover, max_width)
-    local function tab_title(tab_info)
-        local title = tab_info.tab_title
-        -- if the tab title is explicitly set, take that
-        if title and #title > 0 then
-            return title
-        end
-        -- Otherwise, use the title from the active pane
-        -- in that tab
-        return tab_info.active_pane.title
-    end
-
-    local bg = color_names.kanagawa.sumiInk0
-    local fg = color_names.kanagawa.sumiInk4
-
-    local edge_bg = color_names.kanagawa.sumiInk0
-    local edge_fg = color_names.kanagawa.oniViolet
-
-    local title = " " .. wezterm.truncate_right(tab_title(tab), max_width - 2) .. " "
-
-    if title:match("^%s+$") then
-        title = " N/A "
-    end
-
-    if tab.is_active then
-        bg = color_names.kanagawa.sumiInk0
-        fg = color_names.kanagawa.oniViolet
-    elseif hover then
-        fg = color_names.kanagawa.peachRed
-    end
-
-    return {
-        { Background = { Color = edge_bg } },
-        { Foreground = { Color = edge_fg } },
-        { Background = { Color = bg } },
-        { Foreground = { Color = fg } },
-        { Text = title },
-        { Background = { Color = edge_bg } },
-        { Foreground = { Color = fg } },
-        { Text = edges.empty.left },
-        { Background = { Color = bg } },
-        { Foreground = { Color = fg } },
-    }
-end)
-
 return M