Angular, Angular, more Angular, and Redux

I've been working with AngularJS and Angular 6 for 2 years and almost 1 year now respectively, and I do enjoy them both.  I'm also loving Redux, but wish I had known about it when I first started with the AngularJS project, it would have saved me a lot of headache with client side state.  I'm converting the project over, but it's slow going with the amount of work.  I'm also very glad for the Pluralsight courses on them (shameless self plug), the Angular NgRx: Getting Started course by Deborah Kurata and Duncan Hunter is very good for, well, getting started.  I already knew a bit about redux and working with it, but the effects chapter was very useful, and the Architectural Considerations chapter on container presentational pattern I liked a lot.  I'm watching a course on unit testing, but I'm still having difficulty with figuring out what to test on a UI layer.  I'm used to writing tests for things that have logic in them, and I try to keep the logic out of the UI layer.  I can where testing services and probably the container components would be useful, but I don't know about testing a presentational component, it would seem to make for brittle tests, hopefully the videos will be informative in that area.