Feature request: makeHandlerIdempotent Masks Internal Errors

[brianhyder]

Use case

As an engineer implementing the idempotency package, I need to know what is causing the failures while testing the implementation. I must be able to see, in output or attached to the error that is surfaced, to properly handle or mitigate the error. It took additional time to line-by-line debug it.

Example: While testing, I had forgotten to give my lambda permissions to the dynamodb table. The test failed with a generic error with message, Failed to save in progress record to idempotency store.

Example: While testing, my sso session had expired and my credentials were no longer valid. My tests failed with a generic error with a message such as, Failed to update success record to idempotency store.

Place where this happens:

• before
• after
• error

Solution/User Experience

Consider one or both of the following:

1. Log the error out to standard error
2. Attach the original error as an inner error.

const persistenceErr = new IdempotencyPersistenceLayerError(
  'Failed to save in progress record to idempotency store'
);
persistenceErr.inner = originalErr;

Alternatively, you just make each of the custom errors take an additional argument which is the original error.

Alternative solutions

see above

Acknowledgment

• This feature request meets Powertools for AWS Lambda (TypeScript) Tenets
• Should this be considered in other Powertools for AWS Lambda languages? i.e. Python, Java, and .NET

Future readers

Please react with 👍 and your use case to help us understand customer demand.

[dreamorosi]

Hi @brianhyder, thanks for opening the issue and presenting suggestions.

The use case is valid and we shouldn't be catching & masking the errors generated from your code.

We'll be discussing this later today & propose a solution in an upcoming PR.

[brianhyder]

Thank you!