prints random seed in formatter summary

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Change LOG
 
+**2017-04-27**
+- added an option to randomize scenario execution order, so we could
+  ensure that scenarios do not depend on global state.
+
 **2016-10-30** - **v0.6.0**
 - added experimental **events** format, this might be used for unified
   cucumber formats. But should be not adapted widely, since it is highly

README.md

@@ -209,6 +209,7 @@ package main
 import (
 	"os"
 	"testing"
+	"time"
 
 	"github.com/DATA-DOG/godog"
 )
@@ -217,8 +218,9 @@ func TestMain(m *testing.M) {
 	status := godog.RunWithOptions("godogs", func(s *godog.Suite) {
 		FeatureContext(s)
 	}, godog.Options{
-		Format: "progress",
+		Format:    "progress",
-		Paths:  []string{"features"},
+		Paths:     []string{"features"},
+		Randomize: time.Now().UTC().UnixNano(), // randomize scenario execution order
 	})
 
 	if st := m.Run(); st > status {

examples/godogs/godogs_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/DATA-DOG/godog"
 )
@@ -13,8 +14,9 @@ func TestMain(m *testing.M) {
 	status := godog.RunWithOptions("godogs", func(s *godog.Suite) {
 		FeatureContext(s)
 	}, godog.Options{
-		Format: "progress",
+		Format:    "progress",
-		Paths:  []string{"features"},
+		Paths:     []string{"features"},
+		Randomize: time.Now().UTC().UnixNano(), // randomize scenario execution order
 	})
 
 	if st := m.Run(); st > status {

flags.go

@@ -4,7 +4,10 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"math/rand"
+	"strconv"
 	"strings"
+	"time"
 
 	"github.com/DATA-DOG/godog/colors"
 )
@@ -50,7 +53,7 @@ func FlagSet(opt *Options) *flag.FlagSet {
 	set.BoolVar(&opt.ShowStepDefinitions, "d", false, "Print all available step definitions.")
 	set.BoolVar(&opt.StopOnFailure, "stop-on-failure", false, "Stop processing on first failed scenario.")
 	set.BoolVar(&opt.NoColors, "no-colors", false, "Disable ansi colors.")
-	set.Var(&opt.Randomize, "random", descRandomOption)
+	set.Var(&randomSeed{&opt.Randomize}, "random", descRandomOption)
 	set.Usage = usage(set, opt.Output)
 	return set
 }
@@ -147,3 +150,42 @@ func usage(set *flag.FlagSet, w io.Writer) func() {
 		fmt.Fprintln(w, "")
 	}
 }
+
+// randomSeed implements `flag.Value`, see https://golang.org/pkg/flag/#Value
+type randomSeed struct {
+	ref *int64
+}
+
+// Choose randomly assigns a convenient pseudo-random seed value.
+// The resulting seed will be between `1-99999` for later ease of specification.
+func (rs *randomSeed) choose() {
+	r := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
+	*rs.ref = r.Int63n(99998) + 1
+}
+
+func (rs *randomSeed) Set(s string) error {
+	if s == "true" {
+		rs.choose()
+		return nil
+	}
+
+	if s == "false" {
+		*rs.ref = 0
+		return nil
+	}
+
+	i, err := strconv.ParseInt(s, 10, 64)
+	*rs.ref = i
+	return err
+}
+
+func (rs randomSeed) String() string {
+	return strconv.FormatInt(*rs.ref, 10)
+}
+
+// If a Value has an IsBoolFlag() bool method returning true, the command-line
+// parser makes -name equivalent to -name=true rather than using the next
+// command-line argument.
+func (rs *randomSeed) IsBoolFlag() bool {
+	return *rs.ref == 0
+}

fmt.go

@@ -4,8 +4,10 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"os"
 	"reflect"
 	"regexp"
+	"strconv"
 	"strings"
 	"text/template"
 	"time"
@@ -319,6 +321,13 @@ func (f *basefmt) Summary() {
 	}
 	fmt.Fprintln(f.out, elapsed)
 
+	// prints used randomization seed
+	seed, err := strconv.ParseInt(os.Getenv("GODOG_SEED"), 10, 64)
+	if err == nil && seed != 0 {
+		fmt.Fprintln(f.out, "")
+		fmt.Fprintln(f.out, "Randomized with seed:", colors.Yellow(seed))
+	}
+
 	if text := f.snippets(); text != "" {
 		fmt.Fprintln(f.out, yellow("\nYou can implement step definitions for undefined steps with these snippets:"))
 		fmt.Fprintln(f.out, yellow(text))

options.go

@@ -2,9 +2,6 @@ package godog
 
 import (
 	"io"
-	"math/rand"
-	"strconv"
-	"time"
 )
 
 // Options are suite run options
@@ -33,7 +30,7 @@ type Options struct {
 	// Any other value will be used as the random seed for shuffling. Re-using the
 	// same seed will allow you to reproduce the shuffle order of a previous run
 	// to isolate an error condition.
-	Randomize randomSeed
+	Randomize int64
 
 	// Stops on the first failure
 	StopOnFailure bool
@@ -57,40 +54,3 @@ type Options struct {
 	// Where it should print formatter output
 	Output io.Writer
 }
-
-// randomSeed implements `flag.Value`, see https://golang.org/pkg/flag/#Value
-type randomSeed int64
-
-// Choose randomly assigns a convenient pseudo-random seed value.
-// The resulting seed will be between `1-99999` for later ease of specification.
-func (rs *randomSeed) Choose() {
-	r := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
-	*rs = randomSeed(r.Int63n(99998) + 1)
-}
-
-func (rs *randomSeed) Set(s string) error {
-	if s == "true" {
-		rs.Choose()
-		return nil
-	}
-
-	if s == "false" {
-		*rs = 0
-		return nil
-	}
-
-	i, err := strconv.ParseInt(s, 10, 64)
-	*rs = randomSeed(i)
-	return err
-}
-
-func (rs randomSeed) String() string {
-	return strconv.FormatInt(int64(rs), 10)
-}
-
-// If a Value has an IsBoolFlag() bool method returning true, the command-line
-// parser makes -name equivalent to -name=true rather than using the next
-// command-line argument.
-func (rs *randomSeed) IsBoolFlag() bool {
-	return *rs == 0
-}

run.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strconv"
 
 	"github.com/DATA-DOG/godog/colors"
 )
@@ -109,20 +110,17 @@ func RunWithOptions(suite string, contextInitializer func(suite *Suite), opt Opt
 	features, err := parseFeatures(opt.Tags, opt.Paths)
 	fatal(err)
 
-	// handle convenience condition where user specified `-1` in Options struct,
-	// asking us to choose the random value seed for them.
-	if opt.Randomize == -1 {
-		opt.Randomize.Choose()
-	}
-
 	r := runner{
 		fmt:           formatter(suite, output),
 		initializer:   contextInitializer,
 		features:      features,
-		randomSeed:    int64(opt.Randomize),
+		randomSeed:    opt.Randomize,
 		stopOnFailure: opt.StopOnFailure,
 	}
 
+	// store chosen seed in environment, so it could be seen in formatter summary report
+	os.Setenv("GODOG_SEED", strconv.FormatInt(r.randomSeed, 10))
+
 	var failed bool
 	if opt.Concurrency > 1 {
 		failed = r.concurrent(opt.Concurrency)