feat: ResignationSerializer create bug

apps/hrm/serializers.py

@@ -325,4 +325,14 @@ class ResignationSerializer(CustomModelSerializer):
     employee_id_number = serializers.CharField(source="employee.id_number", read_only=True)
     class Meta:
         model = Resignation
-        fields = '__all__'
+        fields = '__all__'
+    
+    def create(self, validated_data):
+        employee:Employee = validated_data['employee']
+        if employee.job_state == Employee.JOB_ON:
+            pass
+        else:
+            raise ParseError('员工不在职,不可创建申请')
+        if Resignation.objects.filter(employee=employee).exists():
+            raise ParseError('该员工已存在离职申请')
+        return super().create(validated_data)