Reason for this change

The previous API for source was designed under the assumption that a Source would either be a Stream or Direct Put if not. Since the alpha module was written, support on the service side for MSK as a Source has been added so we should update the source property to accept an ISource which can then be implemented by different types of Sources.

Description of changes

Replaced the sourceStream property with source.

Changed the source property from IStream to ISource.

Added an ISource interface which is implemented by classes which represent the different Source types. Currently implemented by the KinesisStreamSource class. The MSKSource class can be added in a separate PR.

Added a SourceConfig which contains the property configs for each respective source (as the fields within these property configs are different across each source). In delivery-stream.ts we call the _bind method which will populate and return the correct property config for the Source and that gets directly injected where the L1 CFNDeliveryStream is created. This pattern is also used for Destinations:

    const destinationConfig = props.destination.bind(this, {});
    const sourceConfig = props.source?._bind(this, this._role?.roleArn);

    const resource = new CfnDeliveryStream(this, 'Resource', {
      deliveryStreamEncryptionConfigurationInput: encryptionConfig,
      deliveryStreamName: props.deliveryStreamName,
      deliveryStreamType: props.source ? 'KinesisStreamAsSource' : 'DirectPut',
      ...sourceConfig,
      ...destinationConfig,
    });

Description of how you validated changes

no behavioural changes. the updated integ tests and unit tests still pass existing tests.

exempting integ tests because we don't want the generated CFN to change.

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

BREAKING CHANGE: Replaced the sourceStream property with source. Changed the source property type from IStream to ISource. Instead of passing in the source Stream directly, it will be passed in by calling the appropriate class like so: source: new source.KinesisStreamSource(sourceStream).