Due to T198455 the versions on the templates in tests/jasmine/LanguageAndLexicalCategoryWidget.spec.js and LexemeView.php have become out of sync.
Specifically the spec currently includes a native html <input> whereas the production version includes a <item-selector> component.
It is not possible to put them back in sync without causing the jasmine tests to fail. This can be seen in the following PS: https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikibaseLexeme/+/479183
The tests fail with the widget appearing to be populated by: NaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaN....
This bug was found while working on: T209931 and I suspect due to the fact the entityselector widget from wikibase is not available in the jasmine test environment.