more error details, refactor arguments to interface type

arguments.go

@@ -7,84 +7,122 @@ import (
 
 // Arg is an argument for StepHandler parsed from
 // the regexp submatch to handle the step
-type Arg string
+type Arg struct {
+	value interface{}
+}
 
 // Float64 converts an argument to float64
 // or panics if unable to convert it
-func (a Arg) Float64() float64 {
-	v, err := strconv.ParseFloat(string(a), 64)
+func (a *Arg) Float64() float64 {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	v, err := strconv.ParseFloat(s, 64)
 	if err == nil {
 		return v
 	}
-	panic(fmt.Sprintf(`cannot convert "%s" to float64: %s`, a, err))
+	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 {
-	v, err := strconv.ParseFloat(string(a), 32)
+func (a *Arg) Float32() float32 {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	v, err := strconv.ParseFloat(s, 32)
 	if err == nil {
 		return float32(v)
 	}
-	panic(fmt.Sprintf(`cannot convert "%s" to float32: %s`, a, err))
+	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 {
-	v, err := strconv.ParseInt(string(a), 10, 0)
+func (a *Arg) Int() int {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	v, err := strconv.ParseInt(s, 10, 0)
 	if err == nil {
 		return int(v)
 	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int: %s`, a, err))
+	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 {
-	v, err := strconv.ParseInt(string(a), 10, 64)
+func (a *Arg) Int64() int64 {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	v, err := strconv.ParseInt(s, 10, 64)
 	if err == nil {
 		return v
 	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int64: %s`, a, err))
+	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 {
-	v, err := strconv.ParseInt(string(a), 10, 32)
+func (a *Arg) Int32() int32 {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	v, err := strconv.ParseInt(s, 10, 32)
 	if err == nil {
 		return int32(v)
 	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int32: %s`, a, err))
+	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 {
-	v, err := strconv.ParseInt(string(a), 10, 16)
+func (a *Arg) Int16() int16 {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	v, err := strconv.ParseInt(s, 10, 16)
 	if err == nil {
 		return int16(v)
 	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int16: %s`, a, err))
+	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 {
-	v, err := strconv.ParseInt(string(a), 10, 8)
+func (a *Arg) Int8() int8 {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	v, err := strconv.ParseInt(s, 10, 8)
 	if err == nil {
 		return int8(v)
 	}
-	panic(fmt.Sprintf(`cannot convert "%s" to int8: %s`, a, err))
+	panic(fmt.Sprintf(`cannot convert "%s" to int8: %s`, s, err))
 }
 
 // String converts an argument to string
-func (a Arg) String() string {
-	return string(a)
+func (a *Arg) String() string {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	return s
 }
 
 // Bytes converts an argument string to bytes
-func (a Arg) Bytes() []byte {
-	return []byte(a)
+func (a *Arg) Bytes() []byte {
+	s, ok := a.value.(string)
+	if !ok {
+		panic(fmt.Sprintf(`cannot convert "%v" to string`, a.value))
+	}
+	return []byte(s)
 }

config.go

@@ -108,6 +108,7 @@ func (c *config) validate() error {
 
 func (c *config) features() (lst []*gherkin.Feature, err error) {
 	for _, pat := range c.paths {
+		// check if line number is specified
 		parts := strings.Split(pat, ":")
 		path := parts[0]
 		line := -1
@@ -117,6 +118,7 @@ func (c *config) features() (lst []*gherkin.Feature, err error) {
 				return lst, fmt.Errorf("line number should follow after colon path delimiter")
 			}
 		}
+		// parse features
 		err = filepath.Walk(path, func(p string, f os.FileInfo, err error) error {
 			if err == nil && !f.IsDir() && strings.HasSuffix(p, ".feature") {
 				ft, err := gherkin.Parse(p)
@@ -142,8 +144,14 @@ func (c *config) features() (lst []*gherkin.Feature, err error) {
 			}
 			return err
 		})
-		if err != nil {
-			return lst, fmt.Errorf(`feature path "%s" is not available or accessible`, path)
+		// check error
+		switch {
+		case os.IsNotExist(err):
+			return lst, fmt.Errorf(`feature path "%s" is not available`, path)
+		case os.IsPermission(err):
+			return lst, fmt.Errorf(`feature path "%s" is not accessible`, path)
+		case err != nil:
+			return lst, err
 		}
 	}
 	return

features/hooks.feature

@@ -1 +1,9 @@
 Feature: suite hooks
+  In order to run tasks before and after important events
+  As a test suite
+  I need to provide a way to hook into these events
+
+  Background:
+    Given I have a before scenario hook
+    And a feature path "features/load_features.feature:6"
+    # When I parse and run features

formatter.go

@@ -99,6 +99,10 @@ func (f *pretty) canPrintStep(step *gherkin.Step) bool {
 func (f *pretty) Node(node interface{}) {
 	switch t := node.(type) {
 	case *gherkin.Feature:
+		if f.feature != nil {
+			// not a first feature, add a newline
+			fmt.Println("")
+		}
 		f.feature = t
 		f.doneBackground = false
 		f.background = nil

gherkin/gherkin.go

@@ -281,6 +281,9 @@ func (p *parser) parseFeature() (ft *Feature, err error) {
 
 		// there must be a scenario or scenario outline otherwise
 		if !tok.OfType(SCENARIO, SCENARIO_OUTLINE) {
+			if tok.Type == EOF {
+				return ft, nil // there may not be a scenario defined after background
+			}
 			return ft, p.err("expected a scenario or scenario outline, but got '"+tok.Type.String()+"' instead", tok.Line)
 		}
 

gherkin/lexer_test.go

@@ -51,8 +51,8 @@ func Test_feature_read(t *testing.T) {
 	if tok.Value != val {
 		t.Fatalf("Expected a token value to be '%s', but got: '%s'", val, tok.Value)
 	}
-	if tok.Line != 0 {
-		t.Fatalf("Expected a token line to be '0', but got: '%d'", tok.Line)
+	if tok.Line != 1 {
+		t.Fatalf("Expected a token line to be '1', but got: '%d'", tok.Line)
 	}
 	if tok.Indent != 0 {
 		t.Fatalf("Expected a token identation to be '0', but got: '%d'", tok.Indent)
@@ -66,21 +66,6 @@ func Test_feature_read(t *testing.T) {
 	if tok.Value != val {
 		t.Fatalf("Expected a token value to be '%s', but got: '%s'", val, tok.Value)
 	}
-	if tok.Line != 1 {
-		t.Fatalf("Expected a token line to be '1', but got: '%d'", tok.Line)
-	}
-	if tok.Indent != 2 {
-		t.Fatalf("Expected a token identation to be '2', but got: '%d'", tok.Indent)
-	}
-
-	tok = l.read()
-	if tok.Type != TEXT {
-		t.Fatalf("Expected a 'text' type, but got: '%s'", tok.Type)
-	}
-	val = "as gherkin lexer"
-	if tok.Value != val {
-		t.Fatalf("Expected a token value to be '%s', but got: '%s'", val, tok.Value)
-	}
 	if tok.Line != 2 {
 		t.Fatalf("Expected a token line to be '2', but got: '%d'", tok.Line)
 	}
@@ -92,7 +77,7 @@ func Test_feature_read(t *testing.T) {
 	if tok.Type != TEXT {
 		t.Fatalf("Expected a 'text' type, but got: '%s'", tok.Type)
 	}
-	val = "I need to be able to parse a feature"
+	val = "as gherkin lexer"
 	if tok.Value != val {
 		t.Fatalf("Expected a token value to be '%s', but got: '%s'", val, tok.Value)
 	}
@@ -103,6 +88,21 @@ func Test_feature_read(t *testing.T) {
 		t.Fatalf("Expected a token identation to be '2', but got: '%d'", tok.Indent)
 	}
 
+	tok = l.read()
+	if tok.Type != TEXT {
+		t.Fatalf("Expected a 'text' type, but got: '%s'", tok.Type)
+	}
+	val = "I need to be able to parse a feature"
+	if tok.Value != val {
+		t.Fatalf("Expected a token value to be '%s', but got: '%s'", val, tok.Value)
+	}
+	if tok.Line != 4 {
+		t.Fatalf("Expected a token line to be '4', but got: '%d'", tok.Line)
+	}
+	if tok.Indent != 2 {
+		t.Fatalf("Expected a token identation to be '2', but got: '%d'", tok.Indent)
+	}
+
 	tok = l.read()
 	if tok.Type != EOF {
 		t.Fatalf("Expected an 'eof' type, but got: '%s'", tok.Type)

suite.go

@@ -30,17 +30,17 @@ func (f BeforeScenarioHandlerFunc) BeforeScenario(scenario *gherkin.Scenario) {
 // and that the feature runner can move on to the next
 // step.
 type StepHandler interface {
-	HandleStep(args ...Arg) error
+	HandleStep(args ...*Arg) error
 }
 
 // StepHandlerFunc type is an adapter to allow the use of
 // ordinary functions as Step handlers.  If f is a function
 // with the appropriate signature, StepHandlerFunc(f) is a
 // StepHandler object that calls f.
-type StepHandlerFunc func(...Arg) error
+type StepHandlerFunc func(...*Arg) error
 
 // HandleStep calls f(step_arguments...).
-func (f StepHandlerFunc) HandleStep(args ...Arg) error {
+func (f StepHandlerFunc) HandleStep(args ...*Arg) error {
 	return f(args...)
 }
 
@@ -113,12 +113,18 @@ func (s *suite) Run() {
 
 func (s *suite) runStep(step *gherkin.Step) (err error) {
 	var match *stepMatchHandler
-	var args []Arg
+	var args []*Arg
 	for _, h := range s.stepHandlers {
 		if m := h.expr.FindStringSubmatch(step.Text); len(m) > 0 {
 			match = h
 			for _, a := range m[1:] {
-				args = append(args, Arg(a))
+				args = append(args, &Arg{value: a})
+			}
+			if step.Table != nil {
+				args = append(args, &Arg{value: step.Table})
+			}
+			if step.PyString != nil {
+				args = append(args, &Arg{value: step.PyString})
 			}
 			break
 		}

suite_test.go

@@ -16,24 +16,24 @@ func (s *suiteFeature) BeforeScenario(scenario *gherkin.Scenario) {
 	cfg.paths = []string{}
 }
 
-func (s *suiteFeature) featurePath(args ...Arg) error {
+func (s *suiteFeature) featurePath(args ...*Arg) error {
 	cfg.paths = append(cfg.paths, args[0].String())
 	return nil
 }
 
-func (s *suiteFeature) parseFeatures(args ...Arg) (err error) {
+func (s *suiteFeature) parseFeatures(args ...*Arg) (err error) {
 	s.features, err = cfg.features()
 	return
 }
 
-func (s *suiteFeature) numParsed(args ...Arg) (err error) {
+func (s *suiteFeature) numParsed(args ...*Arg) (err error) {
 	if len(s.features) != args[0].Int() {
 		err = fmt.Errorf("expected %d features to be parsed, but have %d", args[0].Int(), len(s.features))
 	}
 	return
 }
 
-func (s *suiteFeature) numScenariosRegistered(args ...Arg) (err error) {
+func (s *suiteFeature) numScenariosRegistered(args ...*Arg) (err error) {
 	var num int
 	for _, ft := range s.features {
 		num += len(ft.Scenarios)