Nobody is typing "are tests necessary for a view layer that doesn't have much business logic in it beyond passing properties when that view layer is written in Typescript?" into Google.
That would be formal verification.
Formal verification only tells you that the application matches its spec, given a set of assumptions. Only testing can tell you whether the spec matches the business case, and whether the spec assumptions hold.
Paraphrasing Knuth, code that has only been proven correct but not actually tested should always be approached with caution.
Edit: Knuth, not Dijkstra
@ Then there is the limitation of verification tech of course.
And one of the things I say to anxious coworkers who are struggling with testing is that it’s a lot harder than you think.
That said, I think a more accurate title for this post (based on the paragraphs beyond the first one) might be "are tests necessary for a view layer that doesn't have much business logic in it beyond passing properties when that view layer is written in Typescript?" At that point, it's really just a permutation of the question "are tests necessary for the view layer of an application?", which has highly-situational answers.