Lower checks and steps 5x when -test.short flag is set

See #35

engine.go

@@ -119,12 +119,17 @@ func MakeCheck(prop func(*T)) func(*testing.T) {
 func checkTB(tb tb, prop func(*T)) {
 	tb.Helper()
 
+	checks := flags.checks
+	if testing.Short() {
+		checks /= 5
+	}
+
 	start := time.Now()
-	valid, invalid, seed, buf, err1, err2 := doCheck(tb, flags.failfile, flags.checks, baseSeed(), prop)
+	valid, invalid, seed, buf, err1, err2 := doCheck(tb, flags.failfile, checks, baseSeed(), prop)
 	dt := time.Since(start)
 
 	if err1 == nil && err2 == nil {
-		if valid == flags.checks {
+		if valid == checks {
 			tb.Logf("[rapid] OK, passed %v tests (%v)", valid, dt)
 		} else {
 			tb.Errorf("[rapid] only generated %v valid tests from %v total (%v)", valid, valid+invalid, dt)

statemachine.go

@@ -9,6 +9,7 @@ package rapid
 import (
 	"reflect"
 	"sort"
+	"testing"
 )
 
 const (
@@ -56,10 +57,15 @@ type StateMachine interface {
 func Run(m StateMachine) func(*T) {
 	typ := reflect.TypeOf(m)
 
+	steps := flags.steps
+	if testing.Short() {
+		steps /= 5
+	}
+
 	return func(t *T) {
 		t.Helper()
 
-		repeat := newRepeat(0, flags.steps, maxInt)
+		repeat := newRepeat(0, steps, maxInt)
 
 		sm := newStateMachine(typ)
 		if sm.init != nil {