grafana/k6 · error

unsupported fulfill option: '%s'

Error message

unsupported fulfill option: '%s'

What it means

Error "unsupported fulfill option: '%s'" thrown in grafana/k6.

Source

Thrown at internal/js/modules/k6/browser/browser/route_mapping.go:98

	rt := k6ext.Runtime(ctx)
	obj := opts.ToObject(rt)
	for _, k := range obj.Keys() {
		switch k {
		case "body":
			bytesBody, err := k6common.ToBytes(obj.Get(k).Export())
			if err != nil {
				return fopts, err
			}
			fopts.Body = bytesBody
		case "contentType":
			fopts.ContentType = obj.Get(k).String()
		case "headers":
			fopts.Headers = parseHeaders(obj.Get(k).ToObject(rt))
		case "status":
			fopts.Status = obj.Get(k).ToInteger()
		// As we don't support all fields that PW supports, we return an error to inform the user
		default:
			return fopts, fmt.Errorf("unsupported fulfill option: '%s'", k)
		}
	}

	return fopts, nil
}

func parseHeaders(headers *sobek.Object) []common.HTTPHeader {
	headersKeys := headers.Keys()
	result := make([]common.HTTPHeader, 0, len(headersKeys))
	for _, hk := range headersKeys {
		value := headers.Get(hk)
		// Skip undefined headers
		if k6common.IsNullish(value) {
			continue
		}

		result = append(result, common.HTTPHeader{
			Name:  hk,

View on GitHub (pinned to 93accf6570)

When it happens

Trigger: Thrown at internal/js/modules/k6/browser/browser/route_mapping.go:98 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/999de1a6a5b1145d. Report an issue: GitHub.