bug: EventBridge PutEvents not failing invalid entries

[KrazyK786]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

When making a PutEvents call against LocalStack, the provided entries do not appear to be validated for Detail, DetailType, and Source, per the the corresponding behavior of AWS.

Expected Behavior

When making a PutEvents request to LocalStack, I expect to receive failed entries for entries that do not have the required Detail, DetailType, and Source.

How are you starting LocalStack?

Custom (please describe below)

Steps To Reproduce

How are you starting localstack (e.g., bin/localstack command, arguments, or docker-compose.yml)

docker run localstack/localstack

Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

aws events put-events \
  --endpoint-url http://localhost:4566 \
  --region us-east-1 \
  --entries '[{"DetailType": "Test", "Detail": "{\"test1\": \"test2\"}", "Source": "testing.123"}, {"DetailType": "Test2"}]'

running against LocalStack returns:

{
    "FailedEntryCount": 0,
    "Entries": [
        {
            "EventId": "a4aa1d31-4d45-4894-8534-61e0a3d6778e"
        },
        {
            "EventId": "5a52b29c-6d4f-4e9b-9457-0dcb7717229f"
        }
    ]
}

running against AWS returns:

{
    "FailedEntryCount": 1,
    "Entries": [
        {
            "EventId": "28bc32af-7944-0a4f-dfe0-f75703d4b8db"
        },
        {
            "ErrorCode": "InvalidArgument",
            "ErrorMessage": "Parameter Source is not valid. Reason: Source is a required argument."
        }
    ]
}

Environment

- OS: macOS Sonoma 14.4.1
- LocalStack: latest

Anything else?

We did find a previous issue that seemed to address this scenario and referenced the AWS documentation for PutEvents; while it does still list Detail, DetailType, and Source as "Required: No", they have added notes that any entries missing these fields will fail. (We have put a request in to AWS for clearer documentation on this issue.)