tests printing step definitions and stacktrace formatting

run.go

@@ -90,7 +90,7 @@ func RunWithOptions(suite string, contextInitializer func(suite *Suite), opt Opt
 	if opt.ShowStepDefinitions {
 		s := &Suite{}
 		contextInitializer(s)
-		s.printStepDefinitions()
+		s.printStepDefinitions(output)
 		return 0
 	}
 

run_test.go

@@ -0,0 +1,52 @@
+package godog
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/DATA-DOG/godog/colors"
+)
+
+func okStep() error {
+	return nil
+}
+
+func TestPrintsStepDefinitions(t *testing.T) {
+	var buf bytes.Buffer
+	w := colors.Uncolored(&buf)
+	s := &Suite{}
+
+	steps := []string{
+		"^passing step$",
+		`^with name "([^"])"`,
+	}
+
+	for _, step := range steps {
+		s.Step(step, okStep)
+	}
+	s.printStepDefinitions(w)
+
+	out := buf.String()
+	ref := `github.com/DATA-DOG/godog.okStep`
+	for i, def := range strings.Split(strings.TrimSpace(out), "\n") {
+		if idx := strings.Index(def, steps[i]); idx == -1 {
+			t.Fatalf(`step "%s" was not found in output`, steps[i])
+		}
+		if idx := strings.Index(def, ref); idx == -1 {
+			t.Fatalf(`step definition reference "%s" was not found in output: "%s"`, ref, def)
+		}
+	}
+}
+
+func TestPrintsNoStepDefinitionsIfNoneFound(t *testing.T) {
+	var buf bytes.Buffer
+	w := colors.Uncolored(&buf)
+	s := &Suite{}
+	s.printStepDefinitions(w)
+
+	out := strings.TrimSpace(buf.String())
+	if out != "there were no contexts registered, could not find any step definition.." {
+		t.Fatalf("expected output does not match to: %s", out)
+	}
+}

stacktrace_test.go

@@ -0,0 +1,39 @@
+package godog
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func trimLineSpaces(s string) string {
+	var res []string
+	for _, ln := range strings.Split(s, "\n") {
+		res = append(res, strings.TrimSpace(ln))
+	}
+	return strings.Join(res, "\n")
+}
+
+func TestStacktrace(t *testing.T) {
+	err := &traceError{
+		msg:   "err msg",
+		stack: callStack(),
+	}
+
+	expect := "err msg"
+	actual := fmt.Sprintf("%s", err)
+	if expect != actual {
+		t.Fatalf("expected formatted trace error message to be: %s, but got %s", expect, actual)
+	}
+
+	expect = trimLineSpaces(`err msg
+testing.tRunner
+	/usr/lib/go/src/testing/testing.go:657
+runtime.goexit
+	/usr/lib/go/src/runtime/asm_amd64.s:2197`)
+
+	actual = trimLineSpaces(fmt.Sprintf("%+v", err))
+	if expect != actual {
+		t.Fatalf("detaily formatted actual: %s", actual)
+	}
+}

suite.go

@@ -389,7 +389,7 @@ func (s *Suite) runScenario(scenario *gherkin.Scenario, b *gherkin.Background) (
 	return
 }
 
-func (s *Suite) printStepDefinitions() {
+func (s *Suite) printStepDefinitions(w io.Writer) {
 	var longest int
 	for _, def := range s.steps {
 		n := utf8.RuneCountInString(def.Expr.String())
@@ -401,10 +401,10 @@ func (s *Suite) printStepDefinitions() {
 		n := utf8.RuneCountInString(def.Expr.String())
 		location := def.definitionID()
 		spaces := strings.Repeat(" ", longest-n)
-		fmt.Println(yellow(def.Expr.String())+spaces, black("# "+location))
+		fmt.Fprintln(w, yellow(def.Expr.String())+spaces, black("# "+location))
 	}
 	if len(s.steps) == 0 {
-		fmt.Println("there were no contexts registered, could not find any step definition..")
+		fmt.Fprintln(w, "there were no contexts registered, could not find any step definition..")
 	}
 }