gets rid of fatal func, which exits application on unexpected error

fmt.go

@@ -53,20 +53,13 @@ type registeredFormatter struct {
 
 var formatters []*registeredFormatter
 
-func findFmt(format string) (f FormatterFunc, err error) {
-	var names []string
+func findFmt(format string) FormatterFunc {
 	for _, el := range formatters {
 		if el.name == format {
-			f = el.fmt
-			break
+			return el.fmt
 		}
-		names = append(names, el.name)
 	}
-
-	if f == nil {
-		err = fmt.Errorf(`unregistered formatter name: "%s", use one of: %s`, format, strings.Join(names, ", "))
-	}
-	return
+	return nil
 }
 
 // Format registers a feature suite output

fmt_test.go

@@ -2,6 +2,7 @@ package godog
 
 import (
 	"io"
+	"testing"
 
 	"github.com/DATA-DOG/godog/gherkin"
 )
@@ -32,3 +33,25 @@ func (f *testFormatter) Node(node interface{}) {
 }
 
 func (f *testFormatter) Summary() {}
+
+func TestShouldFindFormatter(t *testing.T) {
+	cases := map[string]bool{
+		"progress": true, // true means should be available
+		"unknown":  false,
+		"junit":    true,
+		"cucumber": true,
+		"pretty":   true,
+		"custom":   true, // is available for test purposes only
+		"undef":    false,
+	}
+
+	for name, shouldFind := range cases {
+		actual := findFmt(name)
+		if actual == nil && shouldFind {
+			t.Fatalf("expected %s formatter should be available", name)
+		}
+		if actual != nil && !shouldFind {
+			t.Fatalf("expected %s formatter should not be available", name)
+		}
+	}
+}

run.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"os"
 	"strconv"
+	"strings"
 
 	"github.com/DATA-DOG/godog/colors"
 )
@@ -93,7 +94,7 @@ func RunWithOptions(suite string, contextInitializer func(suite *Suite), opt Opt
 		s := &Suite{}
 		contextInitializer(s)
 		s.printStepDefinitions(output)
-		return 0
+		return 2 // showing help or printing definitions, results exit code - 2
 	}
 
 	if len(opt.Paths) == 0 {
@@ -104,13 +105,28 @@ func RunWithOptions(suite string, contextInitializer func(suite *Suite), opt Opt
 	}
 
 	if opt.Concurrency > 1 && !supportsConcurrency(opt.Format) {
-		fatal(fmt.Errorf("format \"%s\" does not support concurrent execution", opt.Format))
+		fmt.Fprintln(os.Stderr, fmt.Errorf("format \"%s\" does not support concurrent execution", opt.Format))
+		return 1
+	}
+	formatter := findFmt(opt.Format)
+	if nil == formatter {
+		var names []string
+		for name := range AvailableFormatters() {
+			names = append(names, name)
+		}
+		fmt.Fprintln(os.Stderr, fmt.Errorf(
+			`unregistered formatter name: "%s", use one of: %s`,
+			opt.Format,
+			strings.Join(names, ", "),
+		))
+		return 1
 	}
-	formatter, err := findFmt(opt.Format)
-	fatal(err)
 
 	features, err := parseFeatures(opt.Tags, opt.Paths)
-	fatal(err)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		return 1
+	}
 
 	r := runner{
 		fmt:           formatter(suite, output),
@@ -152,8 +168,10 @@ func Run(suite string, contextInitializer func(suite *Suite)) int {
 	var opt Options
 	opt.Output = colors.Colored(os.Stdout)
 	flagSet := FlagSet(&opt)
-	err := flagSet.Parse(os.Args[1:])
-	fatal(err)
+	if err := flagSet.Parse(os.Args[1:]); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		return 1
+	}
 
 	opt.Paths = flagSet.Args()
 

suite_test.go

@@ -137,9 +137,9 @@ func (s *suiteContext) ResetBeforeEachScenario(interface{}) {
 }
 
 func (s *suiteContext) iRunFeatureSuiteWithFormatter(name string) error {
-	f, err := findFmt(name)
-	if err != nil {
-		return err
+	f := findFmt(name)
+	if f == nil {
+		return fmt.Errorf(`formatter "%s" is not available`, name)
 	}
 	s.testedSuite.fmt = f("godog", &s.out)
 	if err := s.parseFeatures(); err != nil {

utils.go

@@ -1,8 +1,6 @@
 package godog
 
 import (
-	"fmt"
-	"os"
 	"strings"
 	"time"
 
@@ -27,14 +25,6 @@ func s(n int) string {
 	return strings.Repeat(" ", n)
 }
 
-// checks the error and exits with error status code
-func fatal(err error) {
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
-	}
-}
-
 var timeNowFunc = func() time.Time {
 	return time.Now()
 }