expected "stroke-dash" to be a number between 0 and 10

Error message

expected "stroke-dash" to be a number between 0 and 10

What it means

The 'stroke-dash' style key must parse as an integer between 0 and 10 inclusive. This error is returned when strconv.Atoi fails or the value falls outside 0–10.

Source

Thrown at d2graph/d2graph.go:365

			return fmt.Errorf(`expected "fill-pattern" to be one of: %s`, strings.Join(d2ast.FillPatterns, ", "))
		}
		s.FillPattern.Value = value
	case "stroke-width":
		if s.StrokeWidth == nil {
			break
		}
		f, err := strconv.Atoi(value)
		if err != nil || (f < 0 || f > 15) {
			return errors.New(`expected "stroke-width" to be a number between 0 and 15`)
		}
		s.StrokeWidth.Value = value
	case "stroke-dash":
		if s.StrokeDash == nil {
			break
		}
		f, err := strconv.Atoi(value)
		if err != nil || (f < 0 || f > 10) {
			return errors.New(`expected "stroke-dash" to be a number between 0 and 10`)
		}
		s.StrokeDash.Value = value
	case "border-radius":
		if s.BorderRadius == nil {
			break
		}
		f, err := strconv.Atoi(value)
		if err != nil || (f < 0) {
			return errors.New(`expected "border-radius" to be a number greater or equal to 0`)
		}
		s.BorderRadius.Value = value
	case "shadow":
		if s.Shadow == nil {
			break
		}
		_, err := strconv.ParseBool(value)
		if err != nil {
			return errors.New(`expected "shadow" to be true or false`)

View on GitHub (pinned to 0d69dca6f5)

Solutions

Use an integer from 0 to 10 for stroke-dash.
Replace keyword values like "dashed" with the numeric equivalent.
Clamp values above 10 down to 10.

Example fix

// before
x.style.stroke-dash: dashed
// after
x.style.stroke-dash: 4

Defensive patterns

Strategy: validation

Validate before calling

n, err := strconv.Atoi(v)
if err != nil || n < 0 || n > 10 {
    return fmt.Errorf("stroke-dash %q must be an integer 0-10", v)
}

Type guard

func validStrokeDash(s string) bool { n, err := strconv.Atoi(s); return err == nil && n >= 0 && n <= 10 }

Try / catch

if err := applyStyle("stroke-dash", value); err != nil {
    if strings.Contains(err.Error(), "stroke-dash") {
        value = "0" // solid line default
    }
}

Prevention

Use numeric dash values 0–10, not CSS keywords.
Clamp before assigning to StrokeDash.Value.
Document the 0–10 limit wherever users input dash styles.

When it happens

Trigger: Setting style 'stroke-dash' to a non-integer ("dashed", "1.5") or out-of-range integer (e.g. 12, -3).

Common situations: D2 authors trying CSS dash-style keywords or picking dash sizes above the allowed maximum.

Related errors

AI-assisted analysis of d2lang/d2@0d69dca6f5 (2026-08-31). Data as JSON: /api/errors/70e580b8b607ebdc. Report an issue: GitHub.