From b41e2579c6bfa0bf5a2f0721f624ebad00a1a60f Mon Sep 17 00:00:00 2001
From: Bert Blommers <bblommers@users.noreply.github.com>
Date: Sat, 12 Aug 2023 21:58:33 +0000
Subject: [PATCH] Scheduler: create_scheduler() now errors on duplicate names
 (#6641)

---
 moto/scheduler/exceptions.py           |  5 +++++
 moto/scheduler/models.py               |  3 +++
 tests/test_scheduler/test_scheduler.py | 20 ++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/moto/scheduler/exceptions.py b/moto/scheduler/exceptions.py
index cb126594b..0e180c2c1 100644
--- a/moto/scheduler/exceptions.py
+++ b/moto/scheduler/exceptions.py
@@ -2,6 +2,11 @@
 from moto.core.exceptions import JsonRESTError
 
 
+class ScheduleExists(JsonRESTError):
+    def __init__(self, name: str) -> None:
+        super().__init__("ConflictException", f"Schedule {name} already exists.")
+
+
 class ScheduleNotFound(JsonRESTError):
     def __init__(self) -> None:
         super().__init__("ResourceNotFoundException", "Schedule not found")
diff --git a/moto/scheduler/models.py b/moto/scheduler/models.py
index f6a559a96..090e9fc53 100644
--- a/moto/scheduler/models.py
+++ b/moto/scheduler/models.py
@@ -5,6 +5,7 @@ from moto.core import BaseBackend, BackendDict, BaseModel
 from moto.core.utils import unix_time
 from moto.utilities.tagging_service import TaggingService
 
+from .exceptions import ScheduleExists
 from .exceptions import ScheduleNotFound, ScheduleGroupNotFound
 
 
@@ -155,6 +156,8 @@ class EventBridgeSchedulerBackend(BaseBackend):
         The ClientToken parameter is not yet implemented
         """
         group = self.schedule_groups[group_name or "default"]
+        if name in group.schedules:
+            raise ScheduleExists(name)
         schedule = Schedule(
             region=self.region_name,
             account_id=self.account_id,
diff --git a/tests/test_scheduler/test_scheduler.py b/tests/test_scheduler/test_scheduler.py
index 9ff962a51..fea2ca458 100644
--- a/tests/test_scheduler/test_scheduler.py
+++ b/tests/test_scheduler/test_scheduler.py
@@ -144,6 +144,26 @@ def test_update_schedule(extra_kwargs):
     assert schedule["CreationDate"] != schedule["LastModificationDate"]
 
 
+@mock_scheduler
+def test_create_duplicate_schedule():
+    client = boto3.client("scheduler", region_name="us-east-1")
+    params = {
+        "ScheduleExpression": "at(2022-12-12T00:00:00)",
+        "FlexibleTimeWindow": {
+            "MaximumWindowInMinutes": 4,
+            "Mode": "FLEXIBLE",
+        },
+        "Target": {"Arn": "arn1", "RoleArn": "arn2"},
+    }
+
+    client.create_schedule(Name="schedule1", **params)
+    with pytest.raises(ClientError) as exc:
+        client.create_schedule(Name="schedule1", **params)
+    err = exc.value.response["Error"]
+    assert err["Code"] == "ConflictException"
+    assert err["Message"] == "Schedule schedule1 already exists."
+
+
 @mock_scheduler
 def test_get_schedule_for_unknown_group():
     client = boto3.client("scheduler", region_name="eu-west-1")