fix: lipgloss.HasDarkBackground hangs in CI environments

Author: jahvon

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/charmbracelet/colorprofile v0.4.3
 	github.com/charmbracelet/x/ansi v0.11.6
 	github.com/charmbracelet/x/exp/teatest/v2 v2.0.0-20260330094520-2dce04b6f8a4
+	github.com/charmbracelet/x/term v0.2.2
 	github.com/muesli/reflow v0.3.0
 	go.uber.org/mock v0.6.0
 	golang.org/x/term v0.41.0
@@ -29,7 +30,6 @@ require (
 	github.com/charmbracelet/x/exp/ordered v0.1.0 // indirect
 	github.com/charmbracelet/x/exp/slice v0.0.0-20250327172914-2fdc97757edf // indirect
 	github.com/charmbracelet/x/exp/strings v0.0.0-20240722160745-212f7b056ed0 // indirect
-	github.com/charmbracelet/x/term v0.2.2 // indirect
 	github.com/charmbracelet/x/termios v0.1.1 // indirect
 	github.com/charmbracelet/x/windows v0.2.2 // indirect
 	github.com/clipperhouse/displaywidth v0.11.0 // indirect

themes/themes.go

@@ -6,6 +6,7 @@ import (
 
 	"charm.land/bubbles/v2/spinner"
 	"charm.land/lipgloss/v2"
+	"github.com/charmbracelet/x/term"
 )
 
 const (
@@ -22,10 +23,21 @@ func NewTheme(name string, cp ColorPalette) Theme {
 		Name:        name,
 		SpinnerType: spinner.Points,
 		Colors:      &colors,
-		isDark:      lipgloss.HasDarkBackground(os.Stdin, os.Stdout),
+		isDark:      detectDarkBackground(),
 	}
 }
 
+// detectDarkBackground checks if the terminal has a dark background.
+// It only queries the terminal when both stdin and stdout are real TTYs,
+// avoiding hangs in CI environments and headless contexts where the
+// terminal won't respond to OSC escape sequences.
+func detectDarkBackground() bool {
+	if !term.IsTerminal(os.Stdin.Fd()) || !term.IsTerminal(os.Stdout.Fd()) {
+		return true // default to dark when not a real terminal
+	}
+	return lipgloss.HasDarkBackground(os.Stdin, os.Stdout)
+}
+
 type ThemeFunc func() Theme
 
 func AllThemes() map[string]ThemeFunc {