issue-677: support task creation with variadic args (#755)

scheduler.go

@@ -535,6 +535,57 @@ func (s *scheduler) NewJob(jobDefinition JobDefinition, task Task, options ...Jo
 	return s.addOrUpdateJob(uuid.Nil, jobDefinition, task, options)
 }
 
+func (s *scheduler) verifyVariadic(taskFunc reflect.Value, tsk task, variadicStart int) error {
+	if err := s.verifyNonVariadic(taskFunc, tsk, variadicStart); err != nil {
+		return err
+	}
+	parameterType := taskFunc.Type().In(variadicStart).Elem().Kind()
+	if parameterType == reflect.Interface || parameterType == reflect.Pointer {
+		parameterType = reflect.Indirect(reflect.ValueOf(taskFunc.Type().In(variadicStart))).Kind()
+	}
+
+	for i := variadicStart; i < len(tsk.parameters); i++ {
+		argumentType := reflect.TypeOf(tsk.parameters[i]).Kind()
+		if argumentType == reflect.Interface || argumentType == reflect.Pointer {
+			argumentType = reflect.TypeOf(tsk.parameters[i]).Elem().Kind()
+		}
+		if argumentType != parameterType {
+			return ErrNewJobWrongTypeOfParameters
+		}
+	}
+	return nil
+}
+
+func (s *scheduler) verifyNonVariadic(taskFunc reflect.Value, tsk task, length int) error {
+	for i := 0; i < length; i++ {
+		t1 := reflect.TypeOf(tsk.parameters[i]).Kind()
+		if t1 == reflect.Interface || t1 == reflect.Pointer {
+			t1 = reflect.TypeOf(tsk.parameters[i]).Elem().Kind()
+		}
+		t2 := reflect.New(taskFunc.Type().In(i)).Elem().Kind()
+		if t2 == reflect.Interface || t2 == reflect.Pointer {
+			t2 = reflect.Indirect(reflect.ValueOf(taskFunc.Type().In(i))).Kind()
+		}
+		if t1 != t2 {
+			return ErrNewJobWrongTypeOfParameters
+		}
+	}
+	return nil
+}
+
+func (s *scheduler) verifyParameterType(taskFunc reflect.Value, tsk task) error {
+	isVariadic := taskFunc.Type().IsVariadic()
+	if isVariadic {
+		variadicStart := taskFunc.Type().NumIn() - 1
+		return s.verifyVariadic(taskFunc, tsk, variadicStart)
+	}
+	expectedParameterLength := taskFunc.Type().NumIn()
+	if len(tsk.parameters) != expectedParameterLength {
+		return ErrNewJobWrongNumberOfParameters
+	}
+	return s.verifyNonVariadic(taskFunc, tsk, expectedParameterLength)
+}
+
 func (s *scheduler) addOrUpdateJob(id uuid.UUID, definition JobDefinition, taskWrapper Task, options []JobOption) (Job, error) {
 	j := internalJob{}
 	if id == uuid.Nil {
@@ -569,23 +620,8 @@ func (s *scheduler) addOrUpdateJob(id uuid.UUID, definition JobDefinition, taskW
 		return nil, ErrNewJobTaskNotFunc
 	}
 
-	expectedParameterLength := taskFunc.Type().NumIn()
-	if len(tsk.parameters) != expectedParameterLength {
-		return nil, ErrNewJobWrongNumberOfParameters
-	}
-
-	for i := 0; i < expectedParameterLength; i++ {
-		t1 := reflect.TypeOf(tsk.parameters[i]).Kind()
-		if t1 == reflect.Interface || t1 == reflect.Pointer {
-			t1 = reflect.TypeOf(tsk.parameters[i]).Elem().Kind()
-		}
-		t2 := reflect.New(taskFunc.Type().In(i)).Elem().Kind()
-		if t2 == reflect.Interface || t2 == reflect.Pointer {
-			t2 = reflect.Indirect(reflect.ValueOf(taskFunc.Type().In(i))).Kind()
-		}
-		if t1 != t2 {
-			return nil, ErrNewJobWrongTypeOfParameters
-		}
+	if err := s.verifyParameterType(taskFunc, tsk); err != nil {
+		return nil, err
 	}
 
 	j.name = runtime.FuncForPC(taskFunc.Pointer()).Name()

scheduler_test.go

@@ -899,6 +899,31 @@ func TestScheduler_NewJobTask(t *testing.T) {
 			NewTask(&testFuncWithParams, "one", "two"),
 			nil,
 		},
+		{
+			"parameter type does not match - different argument types against variadic parameters",
+			NewTask(func(args ...string) {}, "one", 2),
+			ErrNewJobWrongTypeOfParameters,
+		},
+		{
+			"all good string - variadic",
+			NewTask(func(args ...string) {}, "one", "two"),
+			nil,
+		},
+		{
+			"all good mixed variadic",
+			NewTask(func(arg int, args ...string) {}, 1, "one", "two"),
+			nil,
+		},
+		{
+			"all good struct - variadic",
+			NewTask(func(args ...interface{}) {}, struct{}{}),
+			nil,
+		},
+		{
+			"all good no arguments passed in - variadic",
+			NewTask(func(args ...interface{}) {}),
+			nil,
+		},
 	}
 
 	for _, tt := range tests {