build: fix type checker build errors

[eladb]

TS2531: Object is possibly 'null'

Not 100% sure why this suddenly cropped up. Anyone curious to investigate?

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

[costleya]

I checked the tsconfig files in the repository and looked into the latest typescript release changes. Also made sure there were no recent changes in the build image. I also looked at the most recent 2 commits in this repository and did not find anything suspicious.

So - the mystery continues...

[rix0rrr]

Did the @types/node library change?

[rix0rrr]

https://www.npmjs.com/package/@types/node

Published 5 hours ago

[eladb]

@rix0rrr I checked, but couldn't find anything that looked related.

[rix0rrr]

DefinitelyTyped/DefinitelyTyped@18f2165

[rix0rrr]

So we are on 10.x.x of @types/node. To avoid this in the future we can move to 9.x.x which seems frozen. As long as we don't need any Node 10 specific features it shouldn't matter.

[mergify]

Thanks so much for taking the time to contribute to the AWS CDK ❤️

We will shortly assign someone to review this pull request and help get it
merged. In the meantime, please take a minute to make sure you follow this
checklist:

• PR title type(scope): text
  • type: fix, feat, refactor go into CHANGELOG, chore is hidden
  • scope: name of module without aws- or cdk- prefix or postfix (e.g. s3 instead of aws-s3-deployment)
  • text: use all lower-case, do not end with a period, do not include issue refs
• PR Description
  • Rationale: describe rationale of change and approach taken
  • Issues: indicate issues fixed via: fixes #xxx or closes #xxx
  • Breaking?: last paragraph: BREAKING CHANGE: <describe what changed + link for details>
• Testing
  • Unit test added. Prefer to add a new test rather than modify existing tests
  • CLI or init templates change? Re-run/add CLI integration tests
• Documentation
  • README: update module README to describe new features
  • API docs: public APIs must be documented. Copy from official AWS docs when possible
  • Design: for significant features, follow design process