fix(completion): prevent error when getting activeItem with an empty collection

[shortcuts]

Summary

With an empty collections, itemInputValue was undefined which was throwing an error when destructuring it.

Result

• We now check that itemInputValue exists before returning it, otherwise, we return null.
• The activeItemId returned was -1, we now return null if there's no items in the collections.

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 9d55b06:

Sandbox	Source
@algolia/autocomplete-example-github-repositories-custom-plugin	Configuration
@algolia/autocomplete-example-instantsearch	Configuration
@algolia/autocomplete-example-playground	Configuration
@algolia/autocomplete-example-preview-panel-in-modal	Configuration
@algolia/autocomplete-example-react-renderer	Configuration
@algolia/autocomplete-example-starter-algolia	Configuration
@algolia/autocomplete-example-starter	Configuration
@algolia/autocomplete-example-voice-search	Configuration
@algolia/autocomplete-example-vue	Configuration

[Haroenv]

these ! are much more dangerous than they seem sometimes, we need some kind of way to avoid them in the code more (same for InstantSearch)

[francoischalifour]

@Haroenv They are, but to be clear, this wasn't the code responsible for the bug, this was only a refactor. The fix happens in getNextActiveItemId.

[Haroenv]

Thanks for the clarification!