Let herdr's tab bar show the terminal background, so it turns glassy too (#15022)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

config/herdr/config.toml

@@ -6,9 +6,12 @@
 name = "terminal"
 
 [theme.custom]
-# The active tab is drawn as panel_bg text on an accent background, so panel_bg
-# has to be dark for it to read - same colors as status-left's "#[fg=black,bg=blue]"
-panel_bg = "black"
+# The tab bar sits on the terminal's own background, like tmux's bg=default, so
+# it turns see-through with the rest of the terminal under Glassy windows. With
+# no panel_bg the active tab's text falls back to surface_dim, so that is black
+# for dark text on the accent - same colors as status-left's "#[fg=black,bg=blue]"
+panel_bg = "reset"
+surface_dim = "black"
 
 [terminal]
 # Matches -c "#{pane_current_path}" on every split, window, and session

migrations/1791722809.sh

@@ -0,0 +1,21 @@
+echo "Let herdr's tab bar show the terminal's background, so it turns glassy too"
+
+config="$HOME/.config/herdr/config.toml"
+
+# Dotfile managers may own the file or a parent directory through a symlink.
+# Preserve that layout rather than detaching or editing its target.
+path="$config"
+while [[ $path != "$HOME" && $path != / ]]; do
+  if [[ -L $path ]]; then
+    echo "Preserving symlink-managed herdr config: $config"
+    exit 0
+  fi
+  path=$(dirname "$path")
+done
+
+# Only a tab bar still on the shipped black changes; any other choice is kept,
+# and a surface_dim of the user's own is never given a second one.
+if [[ -f $config ]] && grep -qx 'panel_bg = "black"' "$config" && ! grep -q '^[[:space:]]*surface_dim[[:space:]]*=' "$config"; then
+  sed -i 's/^panel_bg = "black"$/panel_bg = "reset"\nsurface_dim = "black"/' "$config"
+  omarchy-restart-herdr || true
+fi

test/shell.d/herdr-glassy-tab-bar-migration-test.sh

@@ -0,0 +1,50 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(dirname "$0")/base-test.sh"
+
+migration="$ROOT/migrations/1791722809.sh"
+test_dir=$(mktemp -d)
+trap 'rm -rf "$test_dir"' EXIT
+
+config="$test_dir/.config/herdr/config.toml"
+mkdir -p "${config%/*}" "$test_dir/bin"
+
+# Reloading herdr would reach the developer's own server.
+printf '#!/bin/bash\necho restart >>"$TEST_LOG"\n' >"$test_dir/bin/omarchy-restart-herdr"
+chmod +x "$test_dir/bin/omarchy-restart-herdr"
+
+run_migration() {
+  : >"$test_dir/log"
+  HOME="$test_dir" PATH="$test_dir/bin:$PATH" TEST_LOG="$test_dir/log" bash -euo pipefail "$migration" >/dev/null
+}
+
+cp "$ROOT/config/herdr/config.toml" "$test_dir/shipped.toml"
+sed -i '/^# The tab bar sits/,/^surface_dim = "black"$/c\# The active tab is drawn as panel_bg text on an accent background\npanel_bg = "black"' "$test_dir/shipped.toml"
+cp "$test_dir/shipped.toml" "$config"
+
+run_migration
+grep -qx 'panel_bg = "reset"' "$config" && (( $(grep -c '^surface_dim' "$config") == 1 )) ||
+  fail "the shipped black tab bar takes the terminal background" "$(cat "$config")"
+grep -qx restart "$test_dir/log" || fail "herdr reloads after the change"
+run_migration
+[[ ! -s $test_dir/log ]] || fail "a second run changes nothing"
+pass "the shipped black tab bar takes the terminal background, once"
+
+# A surface_dim of the user's own, indented or not, is kept as the only one.
+{ cat "$test_dir/shipped.toml"; printf '  surface_dim = "white"\n'; } >"$config"
+cp "$config" "$test_dir/custom.toml"
+run_migration
+cmp -s "$config" "$test_dir/custom.toml" || fail "an indented surface_dim of the user's own is kept, with no second one"
+pass "a surface_dim of the user's own is kept, with no second one"
+
+# A config a dotfile manager links in is left for it to manage.
+mkdir -p "$test_dir/dotfiles"
+cp "$test_dir/shipped.toml" "$test_dir/dotfiles/config.toml"
+rm "$config"
+ln -s "$test_dir/dotfiles/config.toml" "$config"
+run_migration
+[[ -L $config ]] && cmp -s "$test_dir/dotfiles/config.toml" "$test_dir/shipped.toml" ||
+  fail "a linked herdr config is left linked and unchanged"
+pass "a linked herdr config is left alone"