feat: Add subsecond precision to jobs

cron/constantdelay.go

@@ -14,31 +14,23 @@ You can check the original license at:
 		https://github.com/robfig/cron/blob/master/LICENSE
 */
 
-//nolint
 package cron
 
 import "time"
 
 // ConstantDelaySchedule represents a simple recurring duty cycle, e.g. "Every 5 minutes".
-// It does not support jobs more frequent than once a second.
 type ConstantDelaySchedule struct {
 	Delay time.Duration
 }
 
 // Every returns a crontab Schedule that activates once every duration.
-// Delays of less than a second are not supported (will round up to 1 second).
-// Any fields less than a Second are truncated.
 func Every(duration time.Duration) ConstantDelaySchedule {
-	if duration < time.Second {
-		duration = time.Second
-	}
 	return ConstantDelaySchedule{
-		Delay: duration - time.Duration(duration.Nanoseconds())%time.Second,
+		Delay: duration,
 	}
 }
 
 // Next returns the next time this should be run.
-// This rounds so that the next activation time will be on the second.
 func (schedule ConstantDelaySchedule) Next(t time.Time) time.Time {
-	return t.Add(schedule.Delay - time.Duration(t.Nanosecond())*time.Nanosecond)
+	return t.Add(schedule.Delay)
 }

cron/constantdelay_test.go

@@ -14,7 +14,6 @@ You can check the original license at:
 		https://github.com/robfig/cron/blob/master/LICENSE
 */
 
-//nolint
 package cron
 
 import (
@@ -29,9 +28,12 @@ func TestConstantDelayNext(t *testing.T) {
 		expected string
 	}{
 		// Simple cases
-		{"Mon Jul 9 14:45 2012", 15*time.Minute + 50*time.Nanosecond, "Mon Jul 9 15:00 2012"},
+		{"Mon Jul 9 14:45 2012", 15*time.Minute + 50*time.Nanosecond, "Mon Jul 9 15:00:00.00000005 2012"},
 		{"Mon Jul 9 14:59 2012", 15 * time.Minute, "Mon Jul 9 15:14 2012"},
 		{"Mon Jul 9 14:59:59 2012", 15 * time.Minute, "Mon Jul 9 15:14:59 2012"},
+		{"Mon Jul 9 14:45:00 2012", 15 * time.Millisecond, "Mon Jul 9 14:45:00.015 2012"},
+		{"Mon Jul 9 14:45:00.015 2012", 15 * time.Millisecond, "Mon Jul 9 14:45:00.030 2012"},
+		{"Mon Jul 9 14:45:00.000000050 2012", 15 * time.Nanosecond, "Mon Jul 9 14:45:00.000000065 2012"},
 
 		// Wrap around hours
 		{"Mon Jul 9 15:45 2012", 35 * time.Minute, "Mon Jul 9 16:20 2012"},
@@ -47,18 +49,6 @@ func TestConstantDelayNext(t *testing.T) {
 
 		// Wrap around minute, hour, day, month, and year
 		{"Mon Dec 31 23:59:45 2012", 15 * time.Second, "Tue Jan 1 00:00:00 2013"},
-
-		// Round to nearest second on the delay
-		{"Mon Jul 9 14:45 2012", 15*time.Minute + 50*time.Nanosecond, "Mon Jul 9 15:00 2012"},
-
-		// Round up to 1 second if the duration is less.
-		{"Mon Jul 9 14:45:00 2012", 15 * time.Millisecond, "Mon Jul 9 14:45:01 2012"},
-
-		// Round to nearest second when calculating the next time.
-		{"Mon Jul 9 14:45:00.005 2012", 15 * time.Minute, "Mon Jul 9 15:00 2012"},
-
-		// Round to nearest second for both.
-		{"Mon Jul 9 14:45:00.005 2012", 15*time.Minute + 50*time.Nanosecond, "Mon Jul 9 15:00 2012"},
 	}
 
 	for _, c := range tests {

cron/cron_test.go

@@ -789,6 +789,61 @@ func TestMockClock(t *testing.T) {
 	assert.Equal(t, int64(10), counter.Load())
 }
 
+func TestMillisecond(t *testing.T) {
+	clk := clocktesting.NewFakeClock(time.Now())
+	cron := New(WithClock(clk))
+	counter1ms := atomic.Int64{}
+	counter15ms := atomic.Int64{}
+	counter100ms := atomic.Int64{}
+
+	cron.AddFunc("@every 1ms", func() {
+		counter1ms.Add(1)
+	})
+	cron.AddFunc("@every 15ms", func() {
+		counter15ms.Add(1)
+	})
+	cron.AddFunc("@every 100ms", func() {
+		counter100ms.Add(1)
+	})
+
+	cron.Start()
+	defer cron.Stop()
+	for range 1000 {
+		assert.Eventually(t, clk.HasWaiters, OneSecond, 1*time.Millisecond)
+		clk.Step(1 * time.Millisecond)
+	}
+	ctx := cron.Stop()
+	<-ctx.Done()
+
+	assert.Equal(t, int64(1000), counter1ms.Load())
+	assert.Equal(t, int64(66), counter15ms.Load())
+	assert.Equal(t, int64(10), counter100ms.Load())
+}
+
+func TestNanoseconds(t *testing.T) {
+	clk := clocktesting.NewFakeClock(time.Now())
+	cron := New(WithClock(clk))
+
+	counter100ns := atomic.Int64{}
+	cron.AddFunc("@every 100ns", func() {
+		counter100ns.Add(1)
+	})
+
+	cron.Start()
+	defer cron.Stop()
+
+	for range 500 {
+		assert.Eventually(t, clk.HasWaiters, OneSecond, 1*time.Millisecond)
+		clk.Step(5 * time.Nanosecond)
+	}
+	ctx := cron.Stop()
+	<-ctx.Done()
+
+	// 500 * 5 ns = 2500 ns
+	// 2500 every 100ns = 25
+	assert.Equal(t, int64(25), counter100ns.Load())
+}
+
 func TestMultiThreadedStartAndStop(*testing.T) {
 	cron := New()
 	go cron.Run()

cron/parser_test.go

@@ -14,7 +14,6 @@ You can check the original license at:
 		https://github.com/robfig/cron/blob/master/LICENSE
 */
 
-//nolint
 package cron
 
 import (
@@ -167,6 +166,8 @@ func TestParseSchedule(t *testing.T) {
 		{standardParser, "CRON_TZ=UTC  5 * * * *", every5min(time.UTC)},
 		{secondParser, "CRON_TZ=Asia/Tokyo 0 5 * * * *", every5min(tokyo)},
 		{secondParser, "@every 5m", ConstantDelaySchedule{5 * time.Minute}},
+		{secondParser, "@every 5ms", ConstantDelaySchedule{5 * time.Millisecond}},
+		{secondParser, "@every 5ns", ConstantDelaySchedule{5 * time.Nanosecond}},
 		{secondParser, "@midnight", midnight(time.Local)},
 		{secondParser, "TZ=UTC  @midnight", midnight(time.UTC)},
 		{secondParser, "TZ=Asia/Tokyo @midnight", midnight(tokyo)},