fix(jsonview): avoid width underflow in static string rendering

internal/jsonview/staticdisplay.go

@@ -35,16 +35,27 @@ func formatJSON(json gjson.Result, width int) string {
 	return formatResult(json, 0, width)
 }
 
+func truncateStringToWidth(str string, width int) string {
+	if width <= 0 {
+		return ""
+	}
+	if lipgloss.Width(str) <= width {
+		return str
+	}
+	if width == 1 {
+		return "…"
+	}
+	return truncate.String(str, uint(width-1)) + "…"
+}
+
 func formatResult(result gjson.Result, indent, width int) string {
 	switch result.Type {
 	case gjson.String:
 		str := SanitizeTerminalString(result.Str)
 		if str == "" {
 			return nullValueStyle.Render("(empty)")
 		}
-		if lipgloss.Width(str) > width {
-			str = truncate.String(str, uint(width-1)) + "…"
-		}
+		str = truncateStringToWidth(str, width)
 		return stringValueStyle.Render(str)
 	case gjson.Number:
 		return numberValueStyle.Render(result.Raw)

internal/jsonview/staticdisplay_width_test.go

@@ -0,0 +1,23 @@
+package jsonview
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tidwall/gjson"
+)
+
+func TestFormatResultHandlesNonPositiveStringWidth(t *testing.T) {
+	t.Parallel()
+
+	result := gjson.Parse(`"abcdef"`)
+	formatted := formatResult(result, 0, 0)
+
+	assert.NotContains(t, formatted, "abcdef")
+}
+
+func TestTruncateStringToWidthOneUsesEllipsis(t *testing.T) {
+	t.Parallel()
+
+	assert.Equal(t, "…", truncateStringToWidth("abcdef", 1))
+}