Allow simultaneous use of duration and iterations exec shortcuts

This would just produce a shared-iterations scheduler with the specified number of iterations and a maxDuration equal to the passed duration, similar to how it works in the current k6 execution. This should fix #1058.

cmd/config.go

@@ -207,10 +207,13 @@ func getVariableLoopingVUsExecution(stages []lib.Stage, startVUs null.Int) sched
 	return scheduler.ConfigMap{lib.DefaultSchedulerName: ds}
 }
 
-func getSharedIterationsExecution(iterations null.Int, vus null.Int) scheduler.ConfigMap {
+func getSharedIterationsExecution(iterations null.Int, duration types.NullDuration, vus null.Int) scheduler.ConfigMap {
 	ds := scheduler.NewSharedIterationsConfig(lib.DefaultSchedulerName)
 	ds.VUs = vus
 	ds.Iterations = iterations
+	if duration.Valid {
+		ds.MaxDuration = duration
+	}
 	return scheduler.ConfigMap{lib.DefaultSchedulerName: ds}
 }
 
@@ -234,12 +237,19 @@ func checkExecutionMismatch(observedExecution, derivedExecution scheduler.Config
 func deriveExecutionConfig(conf Config) (Config, error) {
 	result := conf
 	switch {
-	case conf.Duration.Valid:
-		if conf.Iterations.Valid {
+	case conf.Iterations.Valid:
+		if len(conf.Stages) > 0 { // stages isn't nil (not set) and isn't explicitly set to empty
 			//TODO: make this an executionConflictConfigError in the next version
-			log.Warnf("Specifying both duration and iterations is deprecated and won't be supported in the future k6 versions")
+			log.Warnf("Specifying both iterations and stages is deprecated and won't be supported in the future k6 versions")
 		}
 
+		result.Execution = getSharedIterationsExecution(conf.Iterations, conf.Duration, conf.VUs)
+		if err := checkExecutionMismatch(conf.Execution, result.Execution, "iterations"); err != nil {
+			return conf, err
+		}
+		// TODO: maybe add a new flag that will be used as a shortcut to per-VU iterations?
+
+	case conf.Duration.Valid:
 		if len(conf.Stages) > 0 { // stages isn't nil (not set) and isn't explicitly set to empty
 			//TODO: make this an executionConflictConfigError in the next version
 			log.Warnf("Specifying both duration and stages is deprecated and won't be supported in the future k6 versions")
@@ -258,23 +268,11 @@ func deriveExecutionConfig(conf Config) (Config, error) {
 		}
 
 	case len(conf.Stages) > 0: // stages isn't nil (not set) and isn't explicitly set to empty
-		if conf.Iterations.Valid {
-			//TODO: make this an executionConflictConfigError in the next version
-			log.Warnf("Specifying both iterations and stages is deprecated and won't be supported in the future k6 versions")
-		}
-
 		result.Execution = getVariableLoopingVUsExecution(conf.Stages, conf.VUs)
 		if err := checkExecutionMismatch(conf.Execution, result.Execution, "stages"); err != nil {
 			return conf, err
 		}
 
-	case conf.Iterations.Valid:
-		result.Execution = getSharedIterationsExecution(conf.Iterations, conf.VUs)
-		if err := checkExecutionMismatch(conf.Execution, result.Execution, "iterations"); err != nil {
-			return conf, err
-		}
-		// TODO: maybe add a new flag that will be used as a shortcut to per-VU iterations?
-
 	default:
 		if conf.Execution != nil { // If someone set this, regardless if its empty
 			//TODO: remove this warning in the next version

cmd/config_consolidation_test.go

@@ -265,21 +265,27 @@ func getConfigConsolidationTestCases() []configConsolidationTestCase {
 			opts{cli: []string{"-s", "1m6s:5", "--vus", "10"}}, exp{},
 			verifyVarLoopingVUs(null.NewInt(10, true), buildStages(66, 5)),
 		},
+		{opts{cli: []string{"-u", "1", "-i", "6", "-d", "10s"}}, exp{}, func(t *testing.T, c Config) {
+			verifySharedIters(I(1), I(6))(t, c)
+			sharedIterConfig := c.Execution[lib.DefaultSchedulerName].(scheduler.SharedIteationsConfig)
+			assert.Equal(t, time.Duration(sharedIterConfig.MaxDuration.Duration), 10*time.Second)
+		}},
 		// This should get a validation error since VUs are more than the shared iterations
 		{opts{cli: []string{"--vus", "10", "-i", "6"}}, exp{validationErrors: true}, verifySharedIters(I(10), I(6))},
 		{opts{cli: []string{"-s", "10s:5", "-s", "10s:"}}, exp{validationErrors: true}, nil},
 		{opts{fs: defaultConfig(`{"stages": [{"duration": "20s"}], "vus": 10}`)}, exp{validationErrors: true}, nil},
 		// These should emit a warning
 		//TODO: in next version, those should be an error
-		{opts{cli: []string{"-u", "1", "-i", "6", "-d", "10s"}}, exp{logWarning: true}, nil},
 		{opts{cli: []string{"-u", "2", "-d", "10s", "-s", "10s:20"}}, exp{logWarning: true}, nil},
 		{opts{cli: []string{"-u", "3", "-i", "5", "-s", "10s:20"}}, exp{logWarning: true}, nil},
 		{opts{cli: []string{"-u", "3", "-d", "0"}}, exp{logWarning: true}, nil},
 		{
 			opts{runner: &lib.Options{
-				VUs:        null.IntFrom(5),
-				Duration:   types.NullDurationFrom(44 * time.Second),
-				Iterations: null.IntFrom(10),
+				VUs:      null.IntFrom(5),
+				Duration: types.NullDurationFrom(44 * time.Second),
+				Stages: []lib.Stage{
+					{Duration: types.NullDurationFrom(3 * time.Second), Target: I(20)},
+				},
 			}}, exp{logWarning: true}, nil,
 		},
 		{opts{fs: defaultConfig(`{"execution": {}}`)}, exp{logWarning: true}, verifyOneIterPerOneVU},
@@ -317,7 +323,7 @@ func getConfigConsolidationTestCases() []configConsolidationTestCase {
 		{
 			opts{
 				runner: &lib.Options{VUs: null.IntFrom(5), Duration: types.NullDurationFrom(50 * time.Second)},
-				cli:    []string{"--iterations", "5"},
+				cli:    []string{"--stage", "5s:5"},
 			},
 			//TODO: this shouldn't be a warning in the next version, but the result will be different
 			exp{logWarning: true}, verifyConstLoopingVUs(I(5), 50*time.Second),
@@ -337,7 +343,7 @@ func getConfigConsolidationTestCases() []configConsolidationTestCase {
 				env:    []string{"K6_VUS=15", "K6_ITERATIONS=15"},
 			},
 			exp{logWarning: true}, //TODO: this won't be a warning in the next version, but the result will be different
-			verifyVarLoopingVUs(null.NewInt(15, true), buildStages(20, 10)),
+			verifySharedIters(I(15), I(15)),
 		},
 		{
 			opts{