Add details to "step is undefined" error (#669)

* Add details to "step is undefined" error

* Update changelog

Author: vearutop

CHANGELOG.md

@@ -8,6 +8,10 @@ This document is formatted according to the principles of [Keep A CHANGELOG](htt
 
 ## Unreleased
 
+### Added
+- Step text is added to "step is undefined" error - ([669](https://github.com/cucumber/godog/pull/669) - [vearutop](https://github.com/vearutop))
+
+### Fixed
 - fix(formatter): On concurrent execution, execute formatter at end of Scenario - ([645](https://github.com/cucumber/godog/pull/645) - [tigh-latte](https://github.com/tigh-latte))
 
 ## [v0.15.0]

internal/formatters/fmt_base_test.go

@@ -42,7 +42,7 @@ And step failed f2s3:4
 
 Scenario: f2s4
 When step passed f2s4:1
-Then step is undefined f2s4:2
+Then something unknown happens f2s4:2
 And step passed f2s4:3
 `)},
 	)
@@ -116,8 +116,8 @@ scenario "f2s3" passed
 
 step invoked: "f2s4:1", passed
 step "step passed f2s4:1" finished with status passed
-.Ustep "step is undefined f2s4:2" finished with status undefined
-scenario "f2s4" ended with error "step is undefined"
+.Ustep "something unknown happens f2s4:2" finished with status undefined
+scenario "f2s4" ended with error "step is undefined: something unknown happens f2s4:2"
 -step "step passed f2s4:3" finished with status skipped
  13
 
@@ -139,12 +139,12 @@ scenario "f2s4" ended with error "step is undefined"
 
 You can implement step definitions for undefined steps with these snippets:
 
-func stepIsUndefinedFS(arg1, arg2, arg3 int) error {
+func somethingUnknownHappensFS(arg1, arg2, arg3 int) error {
 	return godog.ErrPending
 }
 
 func InitializeScenario(ctx *godog.ScenarioContext) {
-	ctx.Step(`+"`"+`^step is undefined f(\d+)s(\d+):(\d+)$`+"`"+`, stepIsUndefinedFS)
+	ctx.Step(`+"`"+`^something unknown happens f(\d+)s(\d+):(\d+)$`+"`"+`, somethingUnknownHappensFS)
 }
 
 `, out.String())

suite.go

@@ -270,7 +270,7 @@ func (s *suite) runStep(ctx context.Context, pickle *Scenario, step *Step, scena
 		s.storage.MustInsertPickleStepResult(sr)
 
 		s.fmt.Undefined(pickle, step, match.GetInternalStepDefinition())
-		return ctx, ErrUndefined
+		return ctx, fmt.Errorf("%w: %s", ErrUndefined, step.Text)
 	}
 
 	if scenarioErr != nil {
@@ -461,7 +461,7 @@ func (s *suite) maybeSubSteps(ctx context.Context, result interface{}) (context.
 		}
 
 		if def == nil {
-			return ctx, ErrUndefined
+			return ctx, fmt.Errorf("%w: %s", ErrUndefined, text)
 		} else {
 			ctx, err = s.runSubStep(ctx, text, def)
 			if err != nil {
@@ -609,7 +609,7 @@ func (s *suite) runPickle(pickle *messages.Pickle) (err error) {
 		s.storage.MustInsertPickleResult(pr)
 
 		s.fmt.Pickle(pickle)
-		return ErrUndefined
+		return fmt.Errorf("%w: no steps in scenario", ErrUndefined)
 	}
 
 	// Before scenario hooks are called in context of first evaluated step

suite_context_test.go

@@ -1008,13 +1008,13 @@ func TestTestSuite_Run(t *testing.T) {
 		{
 			name: "undefined_then_pass_no_strict_doesnt_fail_scenario", afterStepCnt: 2, beforeStepCnt: 2, noStrict: true, suitePasses: true,
 			body: `
-					When step is undefined
+					When something unknown happens
 					Then step passes`,
 			log: `
 					>>>> Before suite
 					>> Before scenario "test"
-					Before step "step is undefined"
-					After step "step is undefined", error: step is undefined, status: undefined
+					Before step "something unknown happens"
+					After step "something unknown happens", error: step is undefined: something unknown happens, status: undefined
 					Before step "step passes"
 					After step "step passes", error: <nil>, status: skipped
 					<< After scenario "test", error: <nil>
@@ -1023,14 +1023,14 @@ func TestTestSuite_Run(t *testing.T) {
 		{
 			name: "undefined_then_pass_fails_scenario", afterStepCnt: 2, beforeStepCnt: 2,
 			body: `
-					When step is undefined
+					When something unknown happens
 					Then step passes`,
 			log: `
 					>>>> Before suite
 					>> Before scenario "test"
-					Before step "step is undefined"
-					After step "step is undefined", error: step is undefined, status: undefined
-					<< After scenario "test", error: step is undefined
+					Before step "something unknown happens"
+					After step "something unknown happens", error: step is undefined: something unknown happens, status: undefined
+					<< After scenario "test", error: step is undefined: something unknown happens
 					Before step "step passes"
 					After step "step passes", error: <nil>, status: skipped
 					<<<< After suite`,
@@ -1039,15 +1039,15 @@ func TestTestSuite_Run(t *testing.T) {
 			name: "fail_then_undefined_fails_scenario", afterStepCnt: 2, beforeStepCnt: 2,
 			body: `
 					When step fails
-					Then step is undefined`,
+					Then something unknown happens`,
 			log: `
 					>>>> Before suite
 					>> Before scenario "test"
 					Before step "step fails"
 					After step "step fails", error: oops, status: failed
 					<< After scenario "test", error: oops
-					Before step "step is undefined"
-					After step "step is undefined", error: step is undefined, status: undefined
+					Before step "something unknown happens"
+					After step "something unknown happens", error: step is undefined: something unknown happens, status: undefined
 					<<<< After suite`,
 		},
 		{