feat: add WithIdentifier (#753) (#754)

Author: pcfreak30

errors.go

@@ -38,6 +38,7 @@ var (
 	ErrWithDistributedElectorNil     = fmt.Errorf("gocron: WithDistributedElector: elector must not be nil")
 	ErrWithDistributedLockerNil      = fmt.Errorf("gocron: WithDistributedLocker: locker must not be nil")
 	ErrWithDistributedJobLockerNil   = fmt.Errorf("gocron: WithDistributedJobLocker: locker must not be nil")
+	ErrWithIdentifierNil             = fmt.Errorf("gocron: WithIdentifier: identifier must not be nil")
 	ErrWithLimitConcurrentJobsZero   = fmt.Errorf("gocron: WithLimitConcurrentJobs: limit must be greater than 0")
 	ErrWithLocationNil               = fmt.Errorf("gocron: WithLocation: location must not be nil")
 	ErrWithLoggerNil                 = fmt.Errorf("gocron: WithLogger: logger must not be nil")

example_test.go

@@ -694,6 +694,27 @@ func ExampleWithGlobalJobOptions() {
 	// [tag4 tag5 tag6]
 }
 
+func ExampleWithIdentifier() {
+	s, _ := NewScheduler()
+	defer func() { _ = s.Shutdown() }()
+
+	j, _ := s.NewJob(
+		DurationJob(
+			time.Second,
+		),
+		NewTask(
+			func(one string, two int) {
+				fmt.Printf("%s, %d", one, two)
+			},
+			"one", 2,
+		),
+		WithIdentifier(uuid.MustParse("87b95dfc-3e71-11ef-9454-0242ac120002")),
+	)
+	fmt.Println(j.ID())
+	// Output:
+	// 87b95dfc-3e71-11ef-9454-0242ac120002
+}
+
 func ExampleWithLimitConcurrentJobs() {
 	_, _ = NewScheduler(
 		WithLimitConcurrentJobs(

job.go

@@ -610,6 +610,20 @@ func WithTags(tags ...string) JobOption {
 	}
 }
 
+// WithIdentifier sets the identifier for the job. The identifier
+// is used to uniquely identify the job and is used for logging
+// and metrics.
+func WithIdentifier(id uuid.UUID) JobOption {
+	return func(j *internalJob) error {
+		if id == uuid.Nil {
+			return ErrWithIdentifierNil
+		}
+
+		j.id = id
+		return nil
+	}
+}
+
 // -----------------------------------------------
 // -----------------------------------------------
 // ------------- Job Event Listeners -------------

scheduler_test.go

@@ -774,6 +774,14 @@ func TestScheduler_NewJobErrors(t *testing.T) {
 			[]JobOption{WithDistributedJobLocker(nil)},
 			ErrWithDistributedJobLockerNil,
 		},
+		{
+			"WithIdentifier is nil",
+			DurationJob(
+				time.Second,
+			),
+			[]JobOption{WithIdentifier(uuid.Nil)},
+			ErrWithIdentifierNil,
+		},
 	}
 
 	for _, tt := range tests {