region-info Fact.find() should throw exception if fact not found

[chelma-amzn]

• I'm submitting a ...

  • 🪲 bug report
  • 🚀 feature request
  • 📚 construct library gap
  • ☎️ security issue or vulnerability => Please see policy
  • ❓ support request => Please see note at the top of this template.

• What is the current behavior?
  If the current behavior is a 🪲bug🪲: Please provide the steps to reproduce

The current behavior is that when a user uses the @aws-cdk/region-info's Fact.find() method, it may return an undefined result. This forces users to perform further checking if they want to pass the result to their own code.

`
const fact = Fact.find(...); // type string?

if (!fact) throw new Error('fact must be provided');

// here fact has type string
`

• What is the expected behavior (or behavior of feature suggested)?

The Fact class should define a method that throws an exception if the fact is not found.

• What is the motivation / use case for changing the behavior or adding this feature?

This enables users to avoid boilerplate code.

• Please tell us about your environment:

N/A

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. associated pull-request, stackoverflow, gitter, etc)

[SomayaB]

Hi @chelma-amzn, thank you for submitting this request! This seems totally reasonable, and not too difficult to implement. If you would like to submit a PR one of us will review it, otherwise someone will update this issue when there is further information!

[stephendwu]

@chelma-amzn Posted a question in the glitter group, but are we trying to define a second method that will throw, or have this original method throw?