fix bug in scheduler, rescheduling jobs immediately

job.go

@@ -20,7 +20,6 @@ type Job struct {
 	fparams           map[string][]interface{} // Map for function and  params of function
 	lock              bool                     // lock the Job from running at same time form multiple instances
 	tags              []string                 // allow the user to tag Jobs with certain labels
-	time              timeHelper               // an instance of timeHelper to interact with the time package
 }
 
 // NewJob creates a new Job with the provided interval
@@ -34,19 +33,12 @@ func NewJob(interval uint64) *Job {
 		funcs:    make(map[string]interface{}),
 		fparams:  make(map[string][]interface{}),
 		tags:     []string{},
-		time:     th,
 	}
 }
 
-// shouldRun returns true if the Job should be run now
-func (j *Job) shouldRun() bool {
-	return j.time.Now().Unix() >= j.nextRun.Unix()
-}
-
 // Run the Job and immediately reschedule it
 func (j *Job) run() {
-	j.lastRun = j.time.Now()
-	go callJobFuncWithParams(j.funcs[j.jobFunc], j.fparams[j.jobFunc])
+	callJobFuncWithParams(j.funcs[j.jobFunc], j.fparams[j.jobFunc])
 }
 
 // Err returns an error if one ocurred while creating the Job

scheduler.go

@@ -70,14 +70,7 @@ func (s *Scheduler) SetLocation(newLocation *time.Location) {
 
 // scheduleNextRun Compute the instant when this Job should run next
 func (s *Scheduler) scheduleNextRun(j *Job) error {
-	now := s.time.Now().In(s.loc)
-	if j.lastRun == s.time.Unix(0, 0) {
-		j.lastRun = now
-	}
-
-	if j.nextRun.After(now) {
-		return nil
-	}
+	now := s.time.Now(s.loc)
 
 	periodDuration, err := j.periodDuration()
 	if err != nil {
@@ -89,7 +82,7 @@ func (s *Scheduler) scheduleNextRun(j *Job) error {
 		j.nextRun = j.lastRun.Add(periodDuration)
 	case days:
 		j.nextRun = s.roundToMidnight(j.lastRun)
-		j.nextRun = j.nextRun.Add(j.atTime)
+		j.nextRun = j.nextRun.Add(j.atTime).Add(periodDuration)
 	case weeks:
 		j.nextRun = s.roundToMidnight(j.lastRun)
 		dayDiff := int(j.startDay)
@@ -118,7 +111,7 @@ func (s *Scheduler) getRunnableJobs() []*Job {
 	var runnableJobs []*Job
 	sort.Sort(s)
 	for _, job := range s.jobs {
-		if job.shouldRun() {
+		if s.shouldRun(job) {
 			runnableJobs = append(runnableJobs, job)
 		} else {
 			break
@@ -130,7 +123,7 @@ func (s *Scheduler) getRunnableJobs() []*Job {
 // NextRun datetime when the next Job should run.
 func (s *Scheduler) NextRun() (*Job, time.Time) {
 	if len(s.jobs) <= 0 {
-		return nil, s.time.Now()
+		return nil, s.time.Now(s.loc)
 	}
 	sort.Sort(s)
 	return s.jobs[0], s.jobs[0].nextRun
@@ -147,11 +140,21 @@ func (s *Scheduler) Every(interval uint64) *Scheduler {
 func (s *Scheduler) RunPending() {
 	runnableJobs := s.getRunnableJobs()
 	for _, job := range runnableJobs {
-		s.runJob(job)
+		s.runAndReschedule(job) // we should handle this error somehow
 	}
 }
 
-func (s *Scheduler) runJob(job *Job) error {
+func (s *Scheduler) runAndReschedule(job *Job) error {
+	if err := s.run(job); err != nil {
+		return err
+	}
+	if err := s.scheduleNextRun(job); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (s *Scheduler) run(job *Job) error {
 	if job.lock {
 		if locker == nil {
 			return fmt.Errorf("trying to lock %s with nil locker", job.jobFunc)
@@ -161,11 +164,10 @@ func (s *Scheduler) runJob(job *Job) error {
 		locker.Lock(key)
 		defer locker.Unlock(key)
 	}
-	job.run()
-	err := s.scheduleNextRun(job)
-	if err != nil {
-		return err
-	}
+
+	job.lastRun = s.time.Now(s.loc)
+	go job.run()
+
 	return nil
 }
 
@@ -177,7 +179,7 @@ func (s *Scheduler) RunAll() {
 // RunAllWithDelay runs all Jobs with delay seconds
 func (s *Scheduler) RunAllWithDelay(d int) {
 	for _, job := range s.jobs {
-		err := s.runJob(job)
+		err := s.run(job)
 		if err != nil {
 			continue
 		}
@@ -253,6 +255,19 @@ func (s *Scheduler) Do(jobFun interface{}, params ...interface{}) (*Job, error)
 	j.jobFunc = fname
 
 	if !j.startsImmediately {
+		periodDuration, err := j.periodDuration()
+		if err != nil {
+			return nil, err
+		}
+
+		if j.lastRun == s.time.Unix(0, 0) {
+			j.lastRun = s.time.Now(s.loc)
+
+			if j.atTime != 0 {
+				j.lastRun = j.lastRun.Add(-periodDuration)
+			}
+		}
+
 		if err := s.scheduleNextRun(j); err != nil {
 			return nil, err
 		}
@@ -283,11 +298,16 @@ func (s *Scheduler) StartAt(t time.Time) *Scheduler {
 // StartImmediately sets the Jobs next run as soon as the scheduler starts
 func (s *Scheduler) StartImmediately() *Scheduler {
 	job := s.getCurrentJob()
-	job.nextRun = s.time.Now().In(s.loc)
+	job.nextRun = s.time.Now(s.loc)
 	job.startsImmediately = true
 	return s
 }
 
+// shouldRun returns true if the Job should be run now
+func (s *Scheduler) shouldRun(j *Job) bool {
+	return s.time.Now(s.loc).Unix() >= j.nextRun.Unix()
+}
+
 // setUnit sets the unit type
 func (s *Scheduler) setUnit(unit timeUnit) {
 	currentJob := s.getCurrentJob()

scheduler_test.go

@@ -29,7 +29,7 @@ func TestExecutionSecond(t *testing.T) {
 func TestExecutionSeconds(t *testing.T) {
 	sched := NewScheduler(time.UTC)
 	jobDone := make(chan bool)
-	executionTimes := make([]int64, 0, 2)
+	var executionTimes []int64
 	numberOfIterations := 2
 
 	sched.Every(2).Seconds().Do(func() {
@@ -75,18 +75,18 @@ func TestStartImmediately(t *testing.T) {
 func TestAt(t *testing.T) {
 	s := NewScheduler(time.UTC)
 
-	// Schedule to run in next minute
+	// Schedule to run in next 2 seconds
 	now := time.Now().UTC()
 	dayJobDone := make(chan bool, 1)
 
 	// Schedule every day At
-	startAt := fmt.Sprintf("%02d:%02d", now.Hour(), now.Add(time.Minute).Minute())
+	startAt := fmt.Sprintf("%02d:%02d:%02d", now.Hour(), now.Minute(), now.Add(time.Second*2).Second())
 	dayJob, _ := s.Every(1).Day().At(startAt).Do(func() {
 		dayJobDone <- true
 	})
 
 	// Expected start time
-	expectedStartTime := time.Date(now.Year(), now.Month(), now.Day(), now.Hour(), now.Add(time.Minute).Minute(), 0, 0, time.UTC)
+	expectedStartTime := time.Date(now.Year(), now.Month(), now.Day(), now.Hour(), now.Minute(), now.Add(time.Second*2).Second(), 0, time.UTC)
 	nextRun := dayJob.NextScheduledTime()
 	assert.Equal(t, expectedStartTime, nextRun)
 

timeHelper.go

@@ -3,7 +3,7 @@ package gocron
 import "time"
 
 type timeHelper interface {
-	Now() time.Time
+	Now(*time.Location) time.Time
 	Unix(int64, int64) time.Time
 	Sleep(time.Duration)
 	Date(int, time.Month, int, int, int, int, int, *time.Location) time.Time
@@ -16,8 +16,9 @@ func newTimeHelper() timeHelper {
 
 type trueTime struct{}
 
-func (t *trueTime) Now() time.Time {
-	return time.Now()
+func (t *trueTime) Now(location *time.Location) time.Time {
+	n := time.Now().In(location)
+	return t.Date(n.Year(), n.Month(), n.Day(), n.Hour(), n.Minute(), n.Second(), 0, location)
 }
 
 func (t *trueTime) Unix(sec int64, nsec int64) time.Time {