From 34bf62f07af6c5bfe8732bcee72d406e5b516550 Mon Sep 17 00:00:00 2001
From: Tom Morelly <tom.morelly@cba.com.au>
Date: Wed, 8 Jan 2025 13:20:21 +1100
Subject: [PATCH] feat(eventListener): add
 BeforeJobRunsSkipIfBeforeFuncErrors()

---
 .github/workflows/file_formatting.yml |  2 +-
 Makefile                              |  2 +-
 example_test.go                       | 23 +++++++++++++++++++++++
 executor.go                           | 14 +++++++++++++-
 job.go                                | 26 ++++++++++++++++++++------
 job_test.go                           |  7 +++++++
 6 files changed, 65 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/file_formatting.yml b/.github/workflows/file_formatting.yml
index 448affef..e8772a61 100644
--- a/.github/workflows/file_formatting.yml
+++ b/.github/workflows/file_formatting.yml
@@ -16,4 +16,4 @@ jobs:
         uses: actions/checkout@v4
       - name: verify example_test.go
         run: |
-          grep "^func " example_test.go | sort -c
+          grep "^func [a-z-A-Z]" example_test.go | sort -c
diff --git a/Makefile b/Makefile
index abaf708a..de747147 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ fmt:
 	@go list -f {{.Dir}} ./... | xargs -I{} gofmt -w -s {}
 
 lint:
-	@grep "^func " example_test.go | sort -c
+	@grep "^func [a-zA-Z]" example_test.go | sort -c
 	@golangci-lint run
 
 test:
diff --git a/example_test.go b/example_test.go
index fb71c204..b077300d 100644
--- a/example_test.go
+++ b/example_test.go
@@ -104,6 +104,29 @@ func ExampleBeforeJobRuns() {
 	)
 }
 
+func ExampleBeforeJobRunsSkipIfBeforeFuncErrors() {
+	s, _ := gocron.NewScheduler()
+	defer func() { _ = s.Shutdown() }()
+
+	_, _ = s.NewJob(
+		gocron.DurationJob(
+			time.Second,
+		),
+		gocron.NewTask(
+			func() {
+				fmt.Println("Will never run, because before job func errors")
+			},
+		),
+		gocron.WithEventListeners(
+			gocron.BeforeJobRunsSkipIfBeforeFuncErrors(
+				func(jobID uuid.UUID, jobName string) error {
+					return fmt.Errorf("error")
+				},
+			),
+		),
+	)
+}
+
 func ExampleCronJob() {
 	s, _ := gocron.NewScheduler()
 	defer func() { _ = s.Shutdown() }()
diff --git a/executor.go b/executor.go
index 439cacbc..3a9dc0d3 100644
--- a/executor.go
+++ b/executor.go
@@ -389,8 +389,21 @@ func (e *executor) runJob(j internalJob, jIn jobIn) {
 		}
 		defer func() { _ = lock.Unlock(j.ctx) }()
 	}
+
 	_ = callJobFuncWithParams(j.beforeJobRuns, j.id, j.name)
 
+	err := callJobFuncWithParams(j.beforeJobRunsSkipIfBeforeFuncErrors, j.id, j.name)
+	if err != nil {
+		e.sendOutForRescheduling(&jIn)
+
+		select {
+		case e.jobsOutCompleted <- j.id:
+		case <-e.ctx.Done():
+		}
+
+		return
+	}
+
 	e.sendOutForRescheduling(&jIn)
 	select {
 	case e.jobsOutCompleted <- j.id:
@@ -398,7 +411,6 @@ func (e *executor) runJob(j internalJob, jIn jobIn) {
 	}
 
 	startTime := time.Now()
-	var err error
 	if j.afterJobRunsWithPanic != nil {
 		err = e.callJobWithRecover(j)
 	} else {
diff --git a/job.go b/job.go
index 4d868e6c..700a0b65 100644
--- a/job.go
+++ b/job.go
@@ -40,12 +40,13 @@ type internalJob struct {
 	startImmediately   bool
 	stopTime           time.Time
 	// event listeners
-	afterJobRuns          func(jobID uuid.UUID, jobName string)
-	beforeJobRuns         func(jobID uuid.UUID, jobName string)
-	afterJobRunsWithError func(jobID uuid.UUID, jobName string, err error)
-	afterJobRunsWithPanic func(jobID uuid.UUID, jobName string, recoverData any)
-	afterLockError        func(jobID uuid.UUID, jobName string, err error)
-	disabledLocker        bool
+	afterJobRuns                        func(jobID uuid.UUID, jobName string)
+	beforeJobRuns                       func(jobID uuid.UUID, jobName string)
+	beforeJobRunsSkipIfBeforeFuncErrors func(jobID uuid.UUID, jobName string) error
+	afterJobRunsWithError               func(jobID uuid.UUID, jobName string, err error)
+	afterJobRunsWithPanic               func(jobID uuid.UUID, jobName string, recoverData any)
+	afterLockError                      func(jobID uuid.UUID, jobName string, err error)
+	disabledLocker                      bool
 
 	locker Locker
 }
@@ -724,6 +725,19 @@ func BeforeJobRuns(eventListenerFunc func(jobID uuid.UUID, jobName string)) Even
 	}
 }
 
+// BeforeJobRunsSkipIfBeforeFuncErrors is used to listen for when a job is about to run and
+// then runs the provided function. If the provided function returns an error, the job will be
+// rescheduled and the current run will be skipped.
+func BeforeJobRunsSkipIfBeforeFuncErrors(eventListenerFunc func(jobID uuid.UUID, jobName string) error) EventListener {
+	return func(j *internalJob) error {
+		if eventListenerFunc == nil {
+			return ErrEventListenerFuncNil
+		}
+		j.beforeJobRunsSkipIfBeforeFuncErrors = eventListenerFunc
+		return nil
+	}
+}
+
 // AfterJobRuns is used to listen for when a job has run
 // without an error, and then run the provided function.
 func AfterJobRuns(eventListenerFunc func(jobID uuid.UUID, jobName string)) EventListener {
diff --git a/job_test.go b/job_test.go
index b7294860..f3d960f6 100644
--- a/job_test.go
+++ b/job_test.go
@@ -482,6 +482,13 @@ func TestWithEventListeners(t *testing.T) {
 			},
 			ErrEventListenerFuncNil,
 		},
+		{
+			"nil before job runs error listener",
+			[]EventListener{
+				BeforeJobRunsSkipIfBeforeFuncErrors(nil),
+			},
+			ErrEventListenerFuncNil,
+		},
 	}
 
 	for _, tt := range tests {