grafana/k6 · error

Somehow a CommonJS module is not wrapped in a function - thi

Error message

Somehow a CommonJS module is not wrapped in a function - this is a k6 bug, please report it (https://github.com/grafana/k6/issues)

What it means

Error "Somehow a CommonJS module is not wrapped in a function - this is a k6 bug, please report it (https://github.com/grafana/k6/issues)" thrown in grafana/k6.

Source

Thrown at js/modules/cjsmodule.go:74

func (cmi *cjsModuleInstance) HasTLA() bool { return false }

func (cmi *cjsModuleInstance) RequestedModules() []string { return cmi.w.RequestedModules() }

func (cmi *cjsModuleInstance) ExecuteModule(
	rt *sobek.Runtime, _, _ func(any) error,
) (sobek.CyclicModuleInstance, error) {
	v, err := rt.RunProgram(cmi.w.prg)
	if err != nil {
		return nil, err
	}

	module := rt.NewObject()
	cmi.exports = rt.NewObject()
	_ = module.Set("exports", cmi.exports)
	call, ok := sobek.AssertFunction(v)
	if !ok {
		panic("Somehow a CommonJS module is not wrapped in a function - " +
			"this is a k6 bug, please report it (https://github.com/grafana/k6/issues)")
	}
	if _, err = call(cmi.exports, module, cmi.exports); err != nil {
		return nil, err
	}

	exportsV := module.Get("exports")
	if sobek.IsNull(exportsV) {
		return nil, errors.New("CommonJS's exports must not be null")
	}
	cmi.exports = exportsV.ToObject(rt)

	// this will be called multiple times we only need to update this on the first VU
	if cmi.w.exportedNames == nil {
		cmi.w.exportedNames = cmi.exports.Keys()
		if cmi.w.exportedNames == nil { // workaround if a CommonJS module does not have exports
			cmi.w.exportedNames = make([]string, 0)
		}

View on GitHub (pinned to 93accf6570)

When it happens

Trigger: Thrown at js/modules/cjsmodule.go:74 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/9b6ace89f8f12bc8. Report an issue: GitHub.