feat(logger): use slog

chain.go

@@ -2,6 +2,7 @@ package cron
 
 import (
 	"fmt"
+	"log/slog"
 	"runtime"
 	"sync"
 	"time"
@@ -38,7 +39,7 @@ func (c Chain) Then(job func()) func() {
 }
 
 // Recover panics in wrapped jobs and log them with the provided logger.
-func Recover(logger Logger) JobWrapper {
+func Recover(logger *slog.Logger) JobWrapper {
 	return func(job func()) func() {
 		return func() {
 			defer func() {
@@ -50,7 +51,7 @@ func Recover(logger Logger) JobWrapper {
 					if !ok {
 						err = fmt.Errorf("%v", r)
 					}
-					logger.Error(err, "panic", "stack", "...\n"+string(buf))
+					logger.Error(err.Error(), "event", "panic", "stack", "...\n"+string(buf))
 				}
 			}()
 			job()
@@ -61,7 +62,7 @@ func Recover(logger Logger) JobWrapper {
 // DelayIfStillRunning serializes jobs, delaying subsequent runs until the
 // previous one is complete. Jobs running after a delay of more than a minute
 // have the delay logged at Info.
-func DelayIfStillRunning(logger Logger) JobWrapper {
+func DelayIfStillRunning(logger *slog.Logger) JobWrapper {
 	return func(job func()) func() {
 		var mu sync.Mutex
 		return func() {
@@ -78,7 +79,7 @@ func DelayIfStillRunning(logger Logger) JobWrapper {
 
 // SkipIfStillRunning skips an invocation of the job if a previous invocation is
 // still running. It logs skips to the given logger at Info level.
-func SkipIfStillRunning(logger Logger) JobWrapper {
+func SkipIfStillRunning(logger *slog.Logger) JobWrapper {
 	return func(job func()) func() {
 		var ch = make(chan struct{}, 1)
 		ch <- struct{}{}

chain_test.go

@@ -2,13 +2,15 @@ package cron
 
 import (
 	"io"
-	"log"
+	"log/slog"
 	"reflect"
 	"sync"
 	"testing"
 	"time"
 )
 
+var discardLogger = slog.New(slog.NewTextHandler(io.Discard, nil))
+
 func appendingJob(slice *[]int, value int) func() {
 	var m sync.Mutex
 	return func() {
@@ -56,12 +58,7 @@ func TestChainRecover(t *testing.T) {
 	})
 
 	t.Run("Recovering JobWrapper recovers", func(t *testing.T) {
-		NewChain(Recover(PrintfLogger(log.New(io.Discard, "", 0)))).
-			Then(panickingJob)()
-	})
-
-	t.Run("composed with the *IfStillRunning wrappers", func(t *testing.T) {
-		NewChain(Recover(PrintfLogger(log.New(io.Discard, "", 0)))).
+		NewChain(Recover(discardLogger)).
 			Then(panickingJob)()
 	})
 }
@@ -101,7 +98,7 @@ func TestChainDelayIfStillRunning(t *testing.T) {
 
 	t.Run("runs immediately", func(t *testing.T) {
 		var j countJob
-		wrappedJob := NewChain(DelayIfStillRunning(DiscardLogger)).Then(j.job())
+		wrappedJob := NewChain(DelayIfStillRunning(discardLogger)).Then(j.job())
 		go wrappedJob()
 		time.Sleep(2 * time.Millisecond) // Give the job 2ms to complete.
 		if c := j.Done(); c != 1 {
@@ -111,7 +108,7 @@ func TestChainDelayIfStillRunning(t *testing.T) {
 
 	t.Run("second run immediate if first done", func(t *testing.T) {
 		var j countJob
-		wrappedJob := NewChain(DelayIfStillRunning(DiscardLogger)).Then(j.job())
+		wrappedJob := NewChain(DelayIfStillRunning(discardLogger)).Then(j.job())
 		go func() {
 			go wrappedJob()
 			time.Sleep(time.Millisecond)
@@ -126,7 +123,7 @@ func TestChainDelayIfStillRunning(t *testing.T) {
 	t.Run("second run delayed if first not done", func(t *testing.T) {
 		var j countJob
 		j.delay = 10 * time.Millisecond
-		wrappedJob := NewChain(DelayIfStillRunning(DiscardLogger)).Then(j.job())
+		wrappedJob := NewChain(DelayIfStillRunning(discardLogger)).Then(j.job())
 		go func() {
 			go wrappedJob()
 			time.Sleep(time.Millisecond)
@@ -155,7 +152,7 @@ func TestChainSkipIfStillRunning(t *testing.T) {
 
 	t.Run("runs immediately", func(t *testing.T) {
 		var j countJob
-		wrappedJob := NewChain(SkipIfStillRunning(DiscardLogger)).Then(j.job())
+		wrappedJob := NewChain(SkipIfStillRunning(discardLogger)).Then(j.job())
 		go wrappedJob()
 		time.Sleep(2 * time.Millisecond) // Give the job 2ms to complete.
 		if c := j.Done(); c != 1 {
@@ -165,7 +162,7 @@ func TestChainSkipIfStillRunning(t *testing.T) {
 
 	t.Run("second run immediate if first done", func(t *testing.T) {
 		var j countJob
-		wrappedJob := NewChain(SkipIfStillRunning(DiscardLogger)).Then(j.job())
+		wrappedJob := NewChain(SkipIfStillRunning(discardLogger)).Then(j.job())
 		go func() {
 			go wrappedJob()
 			time.Sleep(time.Millisecond)
@@ -180,7 +177,7 @@ func TestChainSkipIfStillRunning(t *testing.T) {
 	t.Run("second run skipped if first not done", func(t *testing.T) {
 		var j countJob
 		j.delay = 10 * time.Millisecond
-		wrappedJob := NewChain(SkipIfStillRunning(DiscardLogger)).Then(j.job())
+		wrappedJob := NewChain(SkipIfStillRunning(discardLogger)).Then(j.job())
 		go func() {
 			go wrappedJob()
 			time.Sleep(time.Millisecond)
@@ -206,7 +203,7 @@ func TestChainSkipIfStillRunning(t *testing.T) {
 	t.Run("skip 10 jobs on rapid fire", func(t *testing.T) {
 		var j countJob
 		j.delay = 10 * time.Millisecond
-		wrappedJob := NewChain(SkipIfStillRunning(DiscardLogger)).Then(j.job())
+		wrappedJob := NewChain(SkipIfStillRunning(discardLogger)).Then(j.job())
 		for i := 0; i < 11; i++ {
 			go wrappedJob()
 		}
@@ -221,7 +218,7 @@ func TestChainSkipIfStillRunning(t *testing.T) {
 		var j1, j2 countJob
 		j1.delay = 10 * time.Millisecond
 		j2.delay = 10 * time.Millisecond
-		chain := NewChain(SkipIfStillRunning(DiscardLogger))
+		chain := NewChain(SkipIfStillRunning(discardLogger))
 		wrappedJob1 := chain.Then(j1.job())
 		wrappedJob2 := chain.Then(j2.job())
 		for i := 0; i < 11; i++ {

cron.go

@@ -1,11 +1,12 @@
 package cron
 
 import (
+	"container/heap"
 	"context"
+	"fmt"
+	"log/slog"
 	"sync"
 	"time"
-	"fmt"
-	"container/heap"
 )
 
 // Cron keeps track of any number of entries, invoking the associated func as
@@ -19,11 +20,11 @@ type Cron struct {
 	remove    chan ID
 	snapshot  chan chan []Entry
 	running   bool
-	logger    Logger
+	logger    *slog.Logger
 	runningMu sync.Mutex
 	location  *time.Location
 	parser    ScheduleParser
-	next    ID
+	next      ID
 	jobWaiter sync.WaitGroup
 }
 
@@ -65,17 +66,17 @@ type Entry struct {
 //
 // Available Settings
 //
-//   Time Zone
-//     Description: The time zone in which schedules are interpreted
-//     Default:     time.Local
+//	Time Zone
+//	  Description: The time zone in which schedules are interpreted
+//	  Default:     time.Local
 //
-//   Parser
-//     Description: Parser converts cron spec strings into cron.Schedules.
-//     Default:     Accepts this spec: https://en.wikipedia.org/wiki/Cron
+//	Parser
+//	  Description: Parser converts cron spec strings into cron.Schedules.
+//	  Default:     Accepts this spec: https://en.wikipedia.org/wiki/Cron
 //
-//   Chain
-//     Description: Wrap submitted jobs to customize behavior.
-//     Default:     A chain that recovers panics and logs them to stderr.
+//	Chain
+//	  Description: Wrap submitted jobs to customize behavior.
+//	  Default:     A chain that recovers panics and logs them to stderr.
 //
 // See "cron.With*" to modify the default behavior.
 func New(opts ...Option) *Cron {
@@ -88,10 +89,10 @@ func New(opts ...Option) *Cron {
 		remove:    make(chan ID),
 		running:   false,
 		runningMu: sync.Mutex{},
-		logger:    DefaultLogger,
+		logger:    slog.Default(),
 		location:  time.Local,
 		parser:    standardParser,
-		next: 1,
+		next:      1,
 	}
 	for _, opt := range opts {
 		opt(c)
@@ -115,15 +116,15 @@ func (c *Cron) Add(spec string, cmd func()) (ID, error) {
 func (c *Cron) Schedule(schedule Schedule, cmd func()) (ID, error) {
 	c.runningMu.Lock()
 	defer c.runningMu.Unlock()
-	
+
 	if c.next == 0 {
 		return 0, fmt.Errorf("run out of available ids")
 	}
 
 	entry := &Entry{
-		ID:         c.next,
-		Schedule:   schedule,
-		job:        c.chain.Then(cmd),
+		ID:       c.next,
+		Schedule: schedule,
+		job:      c.chain.Then(cmd),
 	}
 	c.next++
 	if !c.running {

cron_test.go

@@ -2,14 +2,14 @@ package cron
 
 import (
 	"bytes"
+	"container/heap"
 	"fmt"
-	"log"
+	"log/slog"
 	"strings"
 	"sync"
 	"sync/atomic"
 	"testing"
 	"time"
-	"container/heap"
 )
 
 // Many tests schedule a job for every second, and then wait at most a second
@@ -35,8 +35,8 @@ func (sw *syncWriter) String() string {
 	return sw.wr.String()
 }
 
-func newBufLogger(sw *syncWriter) Logger {
-	return PrintfLogger(log.New(sw, "", log.LstdFlags))
+func newBufLogger(sw *syncWriter) *slog.Logger {
+	return slog.New(slog.NewTextHandler(sw, nil))
 }
 
 func TestFuncPanicRecovery(t *testing.T) {
@@ -529,7 +529,7 @@ func TestJob(t *testing.T) {
 
 	cron.Start()
 	defer cron.Stop()
-	
+
 	select {
 	case <-time.After(OneSecond):
 		t.FailNow()

option.go

@@ -1,6 +1,7 @@
 package cron
 
 import (
+	"log/slog"
 	"time"
 )
 
@@ -38,7 +39,7 @@ func WithChain(wrappers ...JobWrapper) Option {
 }
 
 // WithLogger uses the provided logger.
-func WithLogger(logger Logger) Option {
+func WithLogger(logger *slog.Logger) Option {
 	return func(c *Cron) {
 		c.logger = logger
 	}