Stream has no exports

[xanderle]

tsc fails to compile, StreamEventSource, StreamEventSourceProps missing from aws-lambda-event-sources streams file.

Reproduction Steps

npm install @aws-cdk/core
npm install @aws-cdk/aws-lambda-event-sources
tsc

Error Log

node_modules/@aws-cdk/aws-lambda-event-sources/lib/dynamodb.d.ts:3:10 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSource'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';
           ~~~~~~~~~~~~~~~~~

node_modules/@aws-cdk/aws-lambda-event-sources/lib/dynamodb.d.ts:3:29 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSourceProps'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';
                              ~~~~~~~~~~~~~~~~~~~~~~

node_modules/@aws-cdk/aws-lambda-event-sources/lib/kinesis.d.ts:3:10 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSource'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';
           ~~~~~~~~~~~~~~~~~

node_modules/@aws-cdk/aws-lambda-event-sources/lib/kinesis.d.ts:3:29 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSourceProps'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';
                              ~~~~~~~~~~~~~~~~~~~~~~

Environment

• **CLI Version :10.
• **Framework Version: 10.1.
• **OS :MacOS
• **Language : TypeScript

Other

Digging around the node_modules/@aws-cdk/aws-lambda-event-sources/lib/stream.d.ts file shows no exports

---

This is 🐛 Bug Report

[ashwgupt]

We also faced the same issue even when not using either of the Kinesis and Dynamo streams but only SqsEventSource.

Looking at the change log of 1.11.0, the merged work of #4260 has removed redundant code in KinesisEventSource and DynamoEventSource into common StreamEventSource, and that looks like causing it.

[nmussy]

Sorry about that guys. stream.ts is supposed to used internally only, I'm not sure why this error is showing up. The immediate solution would be to export the file like I originally was

@nija-at What do you think?

[nmussy]

Here is an immediate fix in the meantime, using patch-package:

npm i patch-package

tee node_modules/@aws-cdk/aws-lambda-event-sources/lib/stream.d.ts << TS
import lambda = require('@aws-cdk/aws-lambda');
import cdk = require('@aws-cdk/core');
export interface StreamEventSourceProps {
  readonly batchSize?: number;
  readonly startingPosition: lambda.StartingPosition;
  readonly maxBatchingWindow?: cdk.Duration;
}

export declare abstract class StreamEventSource implements lambda.IEventSource {
  readonly props: StreamEventSourceProps;

  protected constructor(props: StreamEventSourceProps);
  public bind(_target: lambda.IFunction): void;
  protected enrichMappingOptions(options: lambda.EventSourceMappingOptions): lambda.EventSourceMappingOptions;
}
TS

npx patch-package @aws-cdk/aws-lambda-event-sources
git add patches/@aws-cdk+aws-lambda-event-sources+1.11.0.patch && git commit

You'll need to add "postinstall": "patch-package" to your package.json scripts field to ensure that the patch will run after each installation.

Hope that helps!

[nija-at]

Unfortunately, we've introduced a bug here. My fault since I suggested this in the PR - #4260 (comment).

Given that StreamEventSource is extended by KinesisEventSource and DynamoEventSource, it will need to be exported so that the typescript compiler can infer the full type definition of the latter two. Same goes for StreamEventSourceProps.

Equally important, we should check why our current tests don't cover this; and how we should cover this gap.

[RomainMuller]

I'm actually curious why the jsii compiler didn't fail on this as I reckon it should have.

[nmussy]

IIRC, JSII was complaining until I added the @internal JSDoc tags

[RomainMuller]

Oh. Adding @internal would have "hidden" this definition from the jsii model indeed, which could make this code compile, but then it may not be valid from a TypeScript perspective anymore (it's fairly difficult to assess this from the compiler, which is why we "have to" let that go here)...

Additionally, we currently have a pre-release test that ensures all libraries can be required, but this happens only on the Javascript layer... This test does not cover the type definitions, which I guess is a gap (but I'm not too sure how easy it will be to actually close that gap).

[nmussy]

I see. My bad then, I thought this was a way to tell JSII not to worry about it not being exposed to the user, but I didn't think this would affect the internal dependencies.

As for testing the definitions, running tsc on a file importing all packages would catch this kind of error.

import '@aws-cdk/alexa-ask';
import '@aws-cdk/app-delivery';
// ...

In v1.11.0:

> npm i @aws-cdk/aws-lambda-event-sources
> echo "import '@aws-cdk/aws-lambda-event-sources';" > test.ts
> tsc test.ts
../node_modules/@aws-cdk/aws-lambda-event-sources/lib/dynamodb.d.ts:3:10 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSource'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';
           ~~~~~~~~~~~~~~~~~

../node_modules/@aws-cdk/aws-lambda-event-sources/lib/dynamodb.d.ts:3:29 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSourceProps'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';
                              ~~~~~~~~~~~~~~~~~~~~~~

../node_modules/@aws-cdk/aws-lambda-event-sources/lib/kinesis.d.ts:3:10 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSource'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';
           ~~~~~~~~~~~~~~~~~

../node_modules/@aws-cdk/aws-lambda-event-sources/lib/kinesis.d.ts:3:29 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSourceProps'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';
                              ~~~~~~~~~~~~~~~~~~~~~~


Found 4 errors.


> echo $?
2

[nija-at]

Agreed. We definitely need a test like that.

#4363

[aukaurea]

@nija-at when it will be fixed?

We are a bit blocked.

Thank you.

[nmussy]

Hey @aukaurea, if you need a fix ASAP, you can look into my previous comment, or downgrade back to the previous release.

Sorry about the inconvenience!

EDIT: fixed the comment link

[aukaurea]

HI @nmussy

Having the same issues with the previous version https://www.npmjs.com/package/@aws-cdk/aws-lambda-event-sources/v/1.10.1

node_modules/@aws-cdk/aws-lambda-event-sources/lib/dynamodb.d.ts:3:10 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSource'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';                                                            ~~~~~~~~~~~~~~~~~                                                                                            
node_modules/@aws-cdk/aws-lambda-event-sources/lib/dynamodb.d.ts:3:29 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSourceProps'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';                                                                               ~~~~~~~~~~~~~~~~~~~~~~                                                                    
node_modules/@aws-cdk/aws-lambda-event-sources/lib/kinesis.d.ts:3:10 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSource'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';                                                            ~~~~~~~~~~~~~~~~~                                                                                            
node_modules/@aws-cdk/aws-lambda-event-sources/lib/kinesis.d.ts:3:29 - error TS2305: Module '"./stream"' has no exported member 'StreamEventSourceProps'.

3 import { StreamEventSource, StreamEventSourceProps } from './stream';  

Packages are used:

    "@aws-cdk/aws-appsync": "1.10.1",
    "@aws-cdk/aws-cloudfront": "1.10.1",
    "@aws-cdk/aws-cognito": "1.10.1",
    "@aws-cdk/aws-dynamodb": "1.10.1",
    "@aws-cdk/aws-events-targets": "1.10.1",
    "@aws-cdk/aws-lambda": "1.10.1",
    "@aws-cdk/aws-lambda-event-sources": "1.10.1",
    "@aws-cdk/aws-route53": "1.10.1",
    "@aws-cdk/aws-s3": "1.10.1",
    "@aws-cdk/aws-s3-deployment": "1.10.1",
    "@aws-cdk/aws-sam": "1.10.1",
    "@aws-cdk/core": "1.10.1",
    "aws-cdk": "1.10.1",

[nija-at]

@aukaurea - We're working on releasing a fix within the next 2 days.