[stepfunctions] Results of DescribeExecution inaccurate for differ execution statuses

The response of DescribeExecution in AWS Step Functions can vary based on the status of the given execution.

The current output type DescribeExecutionOutputTypeDef (for SFN.Client.describe_execution) specifies all items as required which is partly contradictory.

DescribeExecutionOutputTypeDef = TypedDict(
    "DescribeExecutionOutputTypeDef",
    {
        "executionArn": str,
        "stateMachineArn": str,
        "name": str,
        "status": ExecutionStatusType,
        "startDate": datetime,
        "stopDate": datetime,
        "input": str,
        "inputDetails": CloudWatchEventsExecutionDataDetailsTypeDef,
        "output": str,
        "outputDetails": CloudWatchEventsExecutionDataDetailsTypeDef,
        "traceHeader": str,
        "mapRunArn": str,
        "error": str,
        "cause": str,
        "stateMachineVersionArn": str,
        "stateMachineAliasArn": str,
        "redriveCount": int,
        "redriveDate": datetime,
        "redriveStatus": ExecutionRedriveStatusType,
        "redriveStatusReason": str,
        "ResponseMetadata": ResponseMetadataTypeDef,
    },
)

Example query and potential responses

import boto3
sfn_client = boto3.client("stepfunctions")
history = sfn_client.describe_execution(executionArn="arn:...")

For status `RUNNING`

```python { "executionArn": "arn:...", "stateMachineArn": "arn:...", "name": "...", "status": "RUNNING", "startDate": datetime.datetime(...), "input": '{...}', "inputDetails": {"included": True}, "redriveCount": 0, "redriveStatus": "NOT_REDRIVABLE", "redriveStatusReason": "Execution is RUNNING and cannot be redriven", "ResponseMetadata": { ... }, } ```

For status `SUCCEEDED`

```python { "executionArn": "arn:...", "stateMachineArn": "arn:...", "name": "...", "status": "SUCCEEDED", "startDate": datetime.datetime(...), "stopDate": datetime.datetime(...), "input": '{...}', "inputDetails": {"included": True}, "output": '{...}', "outputDetails": {"included": True}, "redriveCount": 0, "redriveStatus": "NOT_REDRIVABLE", "redriveStatusReason": "Execution is SUCCEEDED and cannot be redriven", "ResponseMetadata": { ... }, } ```

For status `FAILED`

```python { "executionArn": "arn:...", "stateMachineArn": "arn:...", "name": "...", "status": "FAILED", "startDate": datetime.datetime(...), "stopDate": datetime.datetime(...), "input": '{...}', "inputDetails": {"included": True}, "traceHeader": "...", "error": "Error", "cause": "...", "redriveCount": 0, "redriveStatus": "REDRIVABLE", "ResponseMetadata": { ... }, } ```

For status `TIMED_OUT`

```python { "executionArn": "arn:...", "stateMachineArn": "arn:...", "name": "...", "status": "TIMED_OUT", "startDate": datetime.datetime(...), "stopDate": datetime.datetime(...), "input": '{...}', "inputDetails": {"included": True}, "traceHeader": "...", "redriveStatus": "NOT_REDRIVABLE", "redriveStatusReason": "Execution's redrivable period has ended", "ResponseMetadata": { ... }, } ```

For status `ABORTED`

```python { "executionArn": "arn:...", "stateMachineArn": "arn:...", "name": "...", "status": "ABORTED", "startDate": datetime.datetime(...), "stopDate": datetime.datetime(...), "input": '{...}', "inputDetails": {"included": True}, "traceHeader": "...", "redriveStatus": "REDRIVABLE", "ResponseMetadata": { ... }, } ```

And there is also status PENDING_REDRIVE for which I don't have an example.

Resolution

It would be great if this builder could produce a union of narrowed variants although it may be difficult to account for all possible scenarios. Otherwise, marking certain fields as NotRequired would suffice. Specifically, it appears stopDate, output, outputDetails, error, cause, traceHeader, and redriveStatusReason are all possibly not included in the response along with mapRunArn, redriveDate, stateMachineAliasArn, and stateMachineVersionArn.

Additional context

Referencing mypy-boto3-stepfunctions v1.35.46

youtype / mypy_boto3_builder