use reflection to set step arguments #9

* 9226bc5 more expressive conversion errors

README.md

@@ -79,19 +79,19 @@ func (c *GodogCart) resetReserve(interface{}) {
 	c.reserve = 0
 }
 
-func (c *GodogCart) thereAreNumGodogsInReserve(args ...*godog.Arg) error {
+func (c *GodogCart) thereAreNumGodogsInReserve(avail int) error {
-	c.reserve = args[0].Int()
+	c.reserve = avail
 	return nil
 }
 
-func (c *GodogCart) iEatNum(args ...*godog.Arg) error {
+func (c *GodogCart) iEatNum(num int) error {
-	c.Eat(args[0].Int())
+	c.Eat(num)
 	return nil
 }
 
-func (c *GodogCart) thereShouldBeNumRemaining(args ...*godog.Arg) error {
+func (c *GodogCart) thereShouldBeNumRemaining(left int) error {
-	if c.Available() != args[0].Int() {
+	if c.Available() != left {
-		return fmt.Errorf("expected %d godogs to be remaining, but there is %d", args[0].Int(), c.Available())
+		return fmt.Errorf("expected %d godogs to be remaining, but there is %d", left, c.Available())
 	}
 	return nil
 }

arguments.go

@@ -1,143 +0,0 @@
-package godog
-
-import (
-	"fmt"
-	"strconv"
-
-	"github.com/cucumber/gherkin-go"
-)
-
-// Arg is an argument for StepHandler parsed from
-// the regexp submatch to handle the step.
-//
-// In future versions, it may be replaced with
-// an argument injection toolkit using reflect
-// package.
-type Arg struct {
-	value interface{}
-}
-
-// StepArgument func creates a step argument.
-// used in cases when calling another step from
-// within a StepHandler function.
-func StepArgument(value interface{}) *Arg {
-	return &Arg{value: value}
-}
-
-// Float64 converts an argument to float64
-// or panics if unable to convert it
-func (a *Arg) Float64() float64 {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	v, err := strconv.ParseFloat(s, 64)
-	if err == nil {
-		return v
-	}
-	panic(fmt.Sprintf(`cannot convert "%s" to float64: %s`, s, err))
-}
-
-// Float32 converts an argument to float32
-// or panics if unable to convert it
-func (a *Arg) Float32() float32 {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	v, err := strconv.ParseFloat(s, 32)
-	if err == nil {
-		return float32(v)
-	}
-	panic(fmt.Sprintf(`cannot convert "%s" to float32: %s`, s, err))
-}
-
-// Int converts an argument to int
-// or panics if unable to convert it
-func (a *Arg) Int() int {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	v, err := strconv.ParseInt(s, 10, 0)
-	if err == nil {
-		return int(v)
-	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int: %s`, s, err))
-}
-
-// Int64 converts an argument to int64
-// or panics if unable to convert it
-func (a *Arg) Int64() int64 {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	v, err := strconv.ParseInt(s, 10, 64)
-	if err == nil {
-		return v
-	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int64: %s`, s, err))
-}
-
-// Int32 converts an argument to int32
-// or panics if unable to convert it
-func (a *Arg) Int32() int32 {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	v, err := strconv.ParseInt(s, 10, 32)
-	if err == nil {
-		return int32(v)
-	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int32: %s`, s, err))
-}
-
-// Int16 converts an argument to int16
-// or panics if unable to convert it
-func (a *Arg) Int16() int16 {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	v, err := strconv.ParseInt(s, 10, 16)
-	if err == nil {
-		return int16(v)
-	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int16: %s`, s, err))
-}
-
-// Int8 converts an argument to int8
-// or panics if unable to convert it
-func (a *Arg) Int8() int8 {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	v, err := strconv.ParseInt(s, 10, 8)
-	if err == nil {
-		return int8(v)
-	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int8: %s`, s, err))
-}
-
-// String converts an argument to string
-func (a *Arg) String() string {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	return s
-}
-
-// Bytes converts an argument string to bytes
-func (a *Arg) Bytes() []byte {
-	s, ok := a.value.(string)
-	a.must(ok, "string")
-	return []byte(s)
-}
-
-// DocString converts an argument to *gherkin.DocString node
-func (a *Arg) DocString() *gherkin.DocString {
-	s, ok := a.value.(*gherkin.DocString)
-	a.must(ok, "*gherkin.DocString")
-	return s
-}
-
-// DataTable converts an argument to *gherkin.DataTable node
-func (a *Arg) DataTable() *gherkin.DataTable {
-	s, ok := a.value.(*gherkin.DataTable)
-	a.must(ok, "*gherkin.DataTable")
-	return s
-}
-
-func (a *Arg) must(ok bool, expected string) {
-	if !ok {
-		panic(fmt.Sprintf(`cannot convert "%v" of type "%T" to type "%s"`, a.value, a.value, expected))
-	}
-}

example/ls_test.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/DATA-DOG/godog"
+	"github.com/cucumber/gherkin-go"
 )
 
 type lsFeature struct {
@@ -24,29 +25,29 @@ func lsFeatureContext(s godog.Suite) {
 	s.Step(`^I should get output:$`, c.iShouldGetOutput)
 }
 
-func (f *lsFeature) iAmInDirectory(args ...*godog.Arg) error {
+func (f *lsFeature) iAmInDirectory(name string) error {
-	f.dir = os.TempDir() + "/" + args[0].String()
+	f.dir = os.TempDir() + "/" + name
 	if err := os.RemoveAll(f.dir); err != nil && !os.IsNotExist(err) {
 		return err
 	}
 	return os.Mkdir(f.dir, 0775)
 }
 
-func (f *lsFeature) iHaveFileOrDirectoryNamed(args ...*godog.Arg) (err error) {
+func (f *lsFeature) iHaveFileOrDirectoryNamed(typ, name string) (err error) {
 	if len(f.dir) == 0 {
 		return fmt.Errorf("the directory was not chosen yet")
 	}
-	switch args[0].String() {
+	switch typ {
 	case "file":
-		err = ioutil.WriteFile(f.dir+"/"+args[1].String(), []byte{}, 0664)
+		err = ioutil.WriteFile(f.dir+"/"+name, []byte{}, 0664)
 	case "directory":
-		err = os.Mkdir(f.dir+"/"+args[1].String(), 0775)
+		err = os.Mkdir(f.dir+"/"+name, 0775)
 	}
 	return err
 }
 
-func (f *lsFeature) iShouldGetOutput(args ...*godog.Arg) error {
+func (f *lsFeature) iShouldGetOutput(names *gherkin.DocString) error {
-	expected := strings.Split(args[0].DocString().Content, "\n")
+	expected := strings.Split(names.Content, "\n")
 	actual := strings.Split(strings.TrimSpace(f.buf.String()), "\n")
 	if len(expected) != len(actual) {
 		return fmt.Errorf("number of expected output lines %d, does not match actual: %d", len(expected), len(actual))
@@ -59,7 +60,7 @@ func (f *lsFeature) iShouldGetOutput(args ...*godog.Arg) error {
 	return nil
 }
 
-func (f *lsFeature) iRunLs(args ...*godog.Arg) error {
+func (f *lsFeature) iRunLs() error {
 	f.buf.Reset()
 	return ls(f.dir, f.buf)
 }

suite.go

@@ -13,28 +13,13 @@ import (
 	"github.com/cucumber/gherkin-go"
 )
 
+var errorInterface = reflect.TypeOf((*error)(nil)).Elem()
+
 type feature struct {
 	*gherkin.Feature
 	Path string `json:"path"`
 }
 
-// Regexp is an unified type for regular expression
-// it can be either a string or a *regexp.Regexp
-type Regexp interface{}
-
-// StepHandler is a func to handle the step
-//
-// The handler receives all arguments which
-// will be matched according to the Regexp
-// which is passed with a step registration.
-//
-// The error in return - represents a reason of failure.
-// All consequent scenario steps are skipped.
-//
-// Returning signals that the step has finished and that
-// the feature runner can move on to the next step.
-type StepHandler func(...*Arg) error
-
 // ErrUndefined is returned in case if step definition was not found
 var ErrUndefined = fmt.Errorf("step is undefined")
 
@@ -47,9 +32,133 @@ var ErrUndefined = fmt.Errorf("step is undefined")
 // when step is matched and is either failed
 // or successful
 type StepDef struct {
-	Args    []*Arg
+	args    []interface{}
-	Handler StepHandler
+	hv      reflect.Value
 	Expr    *regexp.Regexp
+	Handler interface{}
+}
+
+func (sd *StepDef) run() error {
+	typ := sd.hv.Type()
+	if len(sd.args) < typ.NumIn() {
+		return fmt.Errorf("func expects %d arguments, which is more than %d matched from step", typ.NumIn(), len(sd.args))
+	}
+	var values []reflect.Value
+	for i := 0; i < typ.NumIn(); i++ {
+		param := typ.In(i)
+		switch param.Kind() {
+		case reflect.Int:
+			s, err := sd.shouldBeString(i)
+			if err != nil {
+				return err
+			}
+			v, err := strconv.ParseInt(s, 10, 0)
+			if err != nil {
+				return fmt.Errorf(`cannot convert argument %d: "%s" to int: %s`, i, s, err)
+			}
+			values = append(values, reflect.ValueOf(int(v)))
+		case reflect.Int64:
+			s, err := sd.shouldBeString(i)
+			if err != nil {
+				return err
+			}
+			v, err := strconv.ParseInt(s, 10, 64)
+			if err != nil {
+				return fmt.Errorf(`cannot convert argument %d: "%s" to int64: %s`, i, s, err)
+			}
+			values = append(values, reflect.ValueOf(int64(v)))
+		case reflect.Int32:
+			s, err := sd.shouldBeString(i)
+			if err != nil {
+				return err
+			}
+			v, err := strconv.ParseInt(s, 10, 32)
+			if err != nil {
+				return fmt.Errorf(`cannot convert argument %d: "%s" to int32: %s`, i, s, err)
+			}
+			values = append(values, reflect.ValueOf(int32(v)))
+		case reflect.Int16:
+			s, err := sd.shouldBeString(i)
+			if err != nil {
+				return err
+			}
+			v, err := strconv.ParseInt(s, 10, 16)
+			if err != nil {
+				return fmt.Errorf(`cannot convert argument %d: "%s" to int16: %s`, i, s, err)
+			}
+			values = append(values, reflect.ValueOf(int16(v)))
+		case reflect.Int8:
+			s, err := sd.shouldBeString(i)
+			if err != nil {
+				return err
+			}
+			v, err := strconv.ParseInt(s, 10, 8)
+			if err != nil {
+				return fmt.Errorf(`cannot convert argument %d: "%s" to int8: %s`, i, s, err)
+			}
+			values = append(values, reflect.ValueOf(int8(v)))
+		case reflect.String:
+			s, err := sd.shouldBeString(i)
+			if err != nil {
+				return err
+			}
+			values = append(values, reflect.ValueOf(s))
+		case reflect.Float64:
+			s, err := sd.shouldBeString(i)
+			if err != nil {
+				return err
+			}
+			v, err := strconv.ParseFloat(s, 64)
+			if err != nil {
+				return fmt.Errorf(`cannot convert argument %d: "%s" to float64: %s`, i, s, err)
+			}
+			values = append(values, reflect.ValueOf(v))
+		case reflect.Float32:
+			s, err := sd.shouldBeString(i)
+			if err != nil {
+				return err
+			}
+			v, err := strconv.ParseFloat(s, 32)
+			if err != nil {
+				return fmt.Errorf(`cannot convert argument %d: "%s" to float32: %s`, i, s, err)
+			}
+			values = append(values, reflect.ValueOf(float32(v)))
+		case reflect.Ptr:
+			arg := sd.args[i]
+			switch param.Elem().String() {
+			case "gherkin.DocString":
+				v, ok := arg.(*gherkin.DocString)
+				if !ok {
+					return fmt.Errorf(`cannot convert argument %d: "%v" of type "%T" to *gherkin.DocString`, i, arg, arg)
+				}
+				values = append(values, reflect.ValueOf(v))
+			case "gherkin.DataTable":
+				v, ok := arg.(*gherkin.DataTable)
+				if !ok {
+					return fmt.Errorf(`cannot convert argument %d: "%v" of type "%T" to *gherkin.DocString`, i, arg, arg)
+				}
+				values = append(values, reflect.ValueOf(v))
+			default:
+				return fmt.Errorf("the argument %d type %T is not supported", i, arg)
+			}
+		default:
+			return fmt.Errorf("the argument %d type %s is not supported", i, param.Kind())
+		}
+	}
+	ret := sd.hv.Call(values)[0].Interface()
+	if nil == ret {
+		return nil
+	}
+	return ret.(error)
+}
+
+func (sd *StepDef) shouldBeString(idx int) (string, error) {
+	arg := sd.args[idx]
+	s, ok := arg.(string)
+	if !ok {
+		return "", fmt.Errorf(`cannot convert argument %d: "%v" of type "%T" to string`, idx, arg, arg)
+	}
+	return s, nil
 }
 
 // Suite is an interface which allows various contexts
@@ -64,14 +173,36 @@ type StepDef struct {
 // executions are catching panic error since it may
 // be a context specific error.
 type Suite interface {
+	// Run the test suite
 	Run()
-	Step(expr Regexp, h StepHandler)
+
-	// suite events
+	// Registers a step which will execute stepFunc
+	// on step expr match
+	//
+	// expr can be either a string or a *regexp.Regexp
+	// stepFunc is a func to handle the step, arguments
+	// are set from matched step
+	Step(expr interface{}, h interface{})
+
+	// BeforeSuite registers a func to run on initial
+	// suite startup
 	BeforeSuite(f func())
+
+	// BeforeScenario registers a func to run before
+	// every *gherkin.Scenario or *gherkin.ScenarioOutline
 	BeforeScenario(f func(interface{}))
+
+	// BeforeStep register a handler before every step
 	BeforeStep(f func(*gherkin.Step))
+
+	// AfterStep register a handler after every step
 	AfterStep(f func(*gherkin.Step, error))
+
+	// AfterScenario registers a func to run after
+	// every *gherkin.Scenario or *gherkin.ScenarioOutline
 	AfterScenario(f func(interface{}, error))
+
+	// AfterSuite runs func int the end of tests
 	AfterSuite(f func())
 }
 
@@ -117,7 +248,7 @@ func New() Suite {
 //
 // If none of the StepHandlers are matched, then
 // ErrUndefined error will be returned.
-func (s *suite) Step(expr Regexp, h StepHandler) {
+func (s *suite) Step(expr interface{}, stepFunc interface{}) {
 	var regex *regexp.Regexp
 
 	switch t := expr.(type) {
@@ -131,9 +262,21 @@ func (s *suite) Step(expr Regexp, h StepHandler) {
 		panic(fmt.Sprintf("expecting expr to be a *regexp.Regexp or a string, got type: %T", expr))
 	}
 
+	v := reflect.ValueOf(stepFunc)
+	typ := v.Type()
+	if typ.Kind() != reflect.Func {
+		panic(fmt.Sprintf("expected handler to be func, but got: %T", stepFunc))
+	}
+	if typ.NumOut() != 1 {
+		panic(fmt.Sprintf("expected handler to return an error, but it has more values in return: %d", typ.NumOut()))
+	}
+	if typ.Out(0).Kind() != reflect.Interface || !typ.Out(0).Implements(errorInterface) {
+		panic(fmt.Sprintf("expected handler to return an error interface, but we have: %s", typ.Out(0).Kind()))
+	}
 	s.stepHandlers = append(s.stepHandlers, &StepDef{
-		Handler: h,
+		Handler: stepFunc,
 		Expr:    regex,
+		hv:      v,
 	})
 }
 
@@ -262,14 +405,14 @@ func (s *suite) run() {
 func (s *suite) matchStep(step *gherkin.Step) *StepDef {
 	for _, h := range s.stepHandlers {
 		if m := h.Expr.FindStringSubmatch(step.Text); len(m) > 0 {
-			var args []*Arg
+			var args []interface{}
-			for _, a := range m[1:] {
+			for _, m := range m[1:] {
-				args = append(args, &Arg{value: a})
+				args = append(args, m)
 			}
 			if step.Argument != nil {
-				args = append(args, &Arg{value: step.Argument})
+				args = append(args, step.Argument)
 			}
-			h.Args = args
+			h.args = args
 			return h
 		}
 	}
@@ -293,7 +436,7 @@ func (s *suite) runStep(step *gherkin.Step) (err error) {
 		}
 	}()
 
-	if err = match.Handler(match.Args...); err != nil {
+	if err = match.run(); err != nil {
 		s.fmt.Failed(step, match, err)
 	} else {
 		s.fmt.Passed(step, match)

suite_test.go

@@ -2,6 +2,7 @@ package godog
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 
 	"github.com/cucumber/gherkin-go"
@@ -56,12 +57,12 @@ func (s *suiteContext) ResetBeforeEachScenario(interface{}) {
 	s.events = []*firedEvent{}
 }
 
-func (s *suiteContext) followingStepsShouldHave(args ...*Arg) error {
+func (s *suiteContext) followingStepsShouldHave(status string, steps *gherkin.DocString) error {
-	var expected = strings.Split(args[1].DocString().Content, "\n")
+	var expected = strings.Split(steps.Content, "\n")
 	var actual, unmatched []string
 	var matched []int
 
-	switch args[0].String() {
+	switch status {
 	case "passed":
 		for _, st := range s.fmt.passed {
 			actual = append(actual, st.step.Text)
@@ -79,11 +80,11 @@ func (s *suiteContext) followingStepsShouldHave(args ...*Arg) error {
 			actual = append(actual, st.step.Text)
 		}
 	default:
-		return fmt.Errorf("unexpected step status wanted: %s", args[0].String())
+		return fmt.Errorf("unexpected step status wanted: %s", status)
 	}
 
 	if len(expected) > len(actual) {
-		return fmt.Errorf("number of expected %s steps: %d is less than actual %s steps: %d", args[0].String(), len(expected), args[0].String(), len(actual))
+		return fmt.Errorf("number of expected %s steps: %d is less than actual %s steps: %d", status, len(expected), status, len(actual))
 	}
 
 	for _, a := range actual {
@@ -111,10 +112,10 @@ func (s *suiteContext) followingStepsShouldHave(args ...*Arg) error {
 		}
 	}
 
-	return fmt.Errorf("the steps: %s - is not %s", strings.Join(unmatched, ", "), args[0].String())
+	return fmt.Errorf("the steps: %s - is not %s", strings.Join(unmatched, ", "), status)
 }
 
-func (s *suiteContext) iAmListeningToSuiteEvents(args ...*Arg) error {
+func (s *suiteContext) iAmListeningToSuiteEvents() error {
 	s.testedSuite.BeforeSuite(func() {
 		s.events = append(s.events, &firedEvent{"BeforeSuite", []interface{}{}})
 	})
@@ -136,43 +137,41 @@ func (s *suiteContext) iAmListeningToSuiteEvents(args ...*Arg) error {
 	return nil
 }
 
-func (s *suiteContext) aFailingStep(...*Arg) error {
+func (s *suiteContext) aFailingStep() error {
 	return fmt.Errorf("intentional failure")
 }
 
 // parse a given feature file body as a feature
-func (s *suiteContext) aFeatureFile(args ...*Arg) error {
+func (s *suiteContext) aFeatureFile(name string, body *gherkin.DocString) error {
-	name := args[0].String()
+	ft, err := gherkin.ParseFeature(strings.NewReader(body.Content))
-	body := args[1].DocString().Content
-	ft, err := gherkin.ParseFeature(strings.NewReader(body))
 	s.testedSuite.features = append(s.testedSuite.features, &feature{Feature: ft, Path: name})
 	return err
 }
 
-func (s *suiteContext) featurePath(args ...*Arg) error {
+func (s *suiteContext) featurePath(path string) error {
-	s.testedSuite.paths = append(s.testedSuite.paths, args[0].String())
+	s.testedSuite.paths = append(s.testedSuite.paths, path)
 	return nil
 }
 
-func (s *suiteContext) parseFeatures(args ...*Arg) error {
+func (s *suiteContext) parseFeatures() error {
 	return s.testedSuite.parseFeatures()
 }
 
-func (s *suiteContext) theSuiteShouldHave(args ...*Arg) error {
+func (s *suiteContext) theSuiteShouldHave(state string) error {
-	if s.testedSuite.failed && args[0].String() == "passed" {
+	if s.testedSuite.failed && state == "passed" {
 		return fmt.Errorf("the feature suite has failed")
 	}
-	if !s.testedSuite.failed && args[0].String() == "failed" {
+	if !s.testedSuite.failed && state == "failed" {
 		return fmt.Errorf("the feature suite has passed")
 	}
 	return nil
 }
 
-func (s *suiteContext) iShouldHaveNumFeatureFiles(args ...*Arg) error {
+func (s *suiteContext) iShouldHaveNumFeatureFiles(num int, files *gherkin.DocString) error {
-	if len(s.testedSuite.features) != args[0].Int() {
+	if len(s.testedSuite.features) != num {
-		return fmt.Errorf("expected %d features to be parsed, but have %d", args[0].Int(), len(s.testedSuite.features))
+		return fmt.Errorf("expected %d features to be parsed, but have %d", num, len(s.testedSuite.features))
 	}
-	expected := strings.Split(args[1].DocString().Content, "\n")
+	expected := strings.Split(files.Content, "\n")
 	var actual []string
 	for _, ft := range s.testedSuite.features {
 		actual = append(actual, ft.Path)
@@ -188,7 +187,7 @@ func (s *suiteContext) iShouldHaveNumFeatureFiles(args ...*Arg) error {
 	return nil
 }
 
-func (s *suiteContext) iRunFeatureSuite(args ...*Arg) error {
+func (s *suiteContext) iRunFeatureSuite() error {
 	if err := s.parseFeatures(); err != nil {
 		return err
 	}
@@ -196,31 +195,31 @@ func (s *suiteContext) iRunFeatureSuite(args ...*Arg) error {
 	return nil
 }
 
-func (s *suiteContext) numScenariosRegistered(args ...*Arg) (err error) {
+func (s *suiteContext) numScenariosRegistered(expected int) (err error) {
 	var num int
 	for _, ft := range s.testedSuite.features {
 		num += len(ft.ScenarioDefinitions)
 	}
-	if num != args[0].Int() {
+	if num != expected {
-		err = fmt.Errorf("expected %d scenarios to be registered, but got %d", args[0].Int(), num)
+		err = fmt.Errorf("expected %d scenarios to be registered, but got %d", expected, num)
 	}
 	return
 }
 
-func (s *suiteContext) thereWereNumEventsFired(args ...*Arg) error {
+func (s *suiteContext) thereWereNumEventsFired(_ string, expected int, typ string) error {
 	var num int
 	for _, event := range s.events {
-		if event.name == args[2].String() {
+		if event.name == typ {
 			num++
 		}
 	}
-	if num != args[1].Int() {
+	if num != expected {
-		return fmt.Errorf("expected %d %s events to be fired, but got %d", args[1].Int(), args[2].String(), num)
+		return fmt.Errorf("expected %d %s events to be fired, but got %d", expected, typ, num)
 	}
 	return nil
 }
 
-func (s *suiteContext) thereWasEventTriggeredBeforeScenario(args ...*Arg) error {
+func (s *suiteContext) thereWasEventTriggeredBeforeScenario(expected string) error {
 	var found []string
 	for _, event := range s.events {
 		if event.name != "BeforeScenario" {
@@ -234,7 +233,7 @@ func (s *suiteContext) thereWasEventTriggeredBeforeScenario(args ...*Arg) error
 		case *gherkin.ScenarioOutline:
 			name = t.Name
 		}
-		if name == args[0].String() {
+		if name == expected {
 			return nil
 		}
 
@@ -245,22 +244,20 @@ func (s *suiteContext) thereWasEventTriggeredBeforeScenario(args ...*Arg) error
 		return fmt.Errorf("before scenario event was never triggered or listened")
 	}
 
-	return fmt.Errorf(`expected "%s" scenario, but got these fired %s`, args[0].String(), `"`+strings.Join(found, `", "`)+`"`)
+	return fmt.Errorf(`expected "%s" scenario, but got these fired %s`, expected, `"`+strings.Join(found, `", "`)+`"`)
 }
 
-func (s *suiteContext) theseEventsHadToBeFiredForNumberOfTimes(args ...*Arg) error {
+func (s *suiteContext) theseEventsHadToBeFiredForNumberOfTimes(tbl *gherkin.DataTable) error {
-	tbl := args[0].DataTable()
 	if len(tbl.Rows[0].Cells) != 2 {
 		return fmt.Errorf("expected two columns for event table row, got: %d", len(tbl.Rows[0].Cells))
 	}
 
 	for _, row := range tbl.Rows {
-		args := []*Arg{
+		num, err := strconv.ParseInt(row.Cells[1].Value, 10, 0)
-			StepArgument(""), // ignored
+		if err != nil {
-			StepArgument(row.Cells[1].Value),
+			return err
-			StepArgument(row.Cells[0].Value),
 		}
-		if err := s.thereWereNumEventsFired(args...); err != nil {
+		if err := s.thereWereNumEventsFired("", int(num), row.Cells[0].Value); err != nil {
 			return err
 		}
 	}