sort feature files by path when executing, separate the concurrent runner

features/load.feature

@@ -42,6 +42,6 @@ Feature: load features
     When I parse features
     Then I should have 2 feature files:
       """
-      features/load.feature
       features/events.feature
+      features/load.feature
       """

run.go

@@ -3,29 +3,24 @@ package godog
 import (
 	"fmt"
 	"os"
-	"sync"
 )
 
 type initializer func(*Suite)
 
 type runner struct {
-	sync.WaitGroup
-
-	semaphore     chan int
 	stopOnFailure bool
 	features      []*feature
 	fmt           Formatter // needs to support concurrency
 	initializer   initializer
 }
 
-func (r *runner) run() (failed bool) {
-	r.Add(len(r.features))
-	for _, ft := range r.features {
+func (r *runner) concurrent(rate int) (failed bool) {
+	queue := make(chan int, rate)
+	for i, ft := range r.features {
+		queue <- i // reserve space in queue
 		go func(fail *bool, feat *feature) {
-			r.semaphore <- 1
 			defer func() {
-				r.Done()
-				<-r.semaphore
+				<-queue // free a space in queue
 			}()
 			if r.stopOnFailure && *fail {
 				return
@@ -42,12 +37,30 @@ func (r *runner) run() (failed bool) {
 			}
 		}(&failed, ft)
 	}
-	r.Wait()
+	// wait until last are processed
+	for i := 0; i < rate; i++ {
+		queue <- i
+	}
+	close(queue)
 
+	// print summary
 	r.fmt.Summary()
 	return
 }
 
+func (r *runner) run() (failed bool) {
+	suite := &Suite{
+		fmt:           r.fmt,
+		stopOnFailure: r.stopOnFailure,
+		features:      r.features,
+	}
+	r.initializer(suite)
+	suite.run()
+
+	r.fmt.Summary()
+	return suite.failed
+}
+
 // Run creates and runs the feature suite.
 // uses contextInitializer to register contexts
 //
@@ -94,12 +107,17 @@ func Run(contextInitializer func(suite *Suite)) int {
 	r := runner{
 		fmt:           formatter,
 		initializer:   contextInitializer,
-		semaphore:     make(chan int, concurrency),
 		features:      features,
 		stopOnFailure: sof,
 	}
 
-	if failed := r.run(); failed {
+	var failed bool
+	if concurrency > 1 {
+		failed = r.concurrent(concurrency)
+	} else {
+		failed = r.run()
+	}
+	if failed {
 		return 1
 	}
 	return 0

suite.go

@@ -6,6 +6,7 @@ import (
 	"path/filepath"
 	"reflect"
 	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 	"unicode/utf8"
@@ -445,9 +446,16 @@ func parseFeatures(filter string, paths []string) (features []*feature, err erro
 			return features, err
 		}
 	}
+	sort.Sort(featuresSortedByPath(features))
 	return
 }
 
+type featuresSortedByPath []*feature
+
+func (s featuresSortedByPath) Len() int           { return len(s) }
+func (s featuresSortedByPath) Less(i, j int) bool { return s[i].Path < s[j].Path }
+func (s featuresSortedByPath) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
 func applyTagFilter(tags string, ft *gherkin.Feature) {
 	if len(tags) == 0 {
 		return

utils.go

@@ -44,7 +44,7 @@ func s(n int) string {
 // checks the error and exits with error status code
 func fatal(err error) {
 	if err != nil {
-		fmt.Println(err)
+		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}
 }