Rule proposition: No async in computed property functions

A common issue that beginners run into is relying on async code in a computed property function, even though we warn about it in the docs. This might not be possible to identify 100% of the time, but it would be nice for the linter to warn about:

• async/await
• passing a function as a function argument (covers promises and callbacks)

Am I missing any cases where either of the above would actually be valid inside a computed property function?

[michalsnik]

I think we should cover first 3 examples, and the last one would be to detect presence of any of then, catch or finally in all CallExpressions inside computed property’s body. Bur I’m against checking arguments response and res as they might be used even if the body has nothing to do with async computing. For example application has a module that gathers users’ responses for a given topic, than we could have a computed property activeResponse in which we’d like to call a utility function with response argument, or short res. I had similar case with route in other plugin. I thought it’s enough to check for that name and then someone had an app with generating routes on google maps 😄

[michalsnik]

Done in v3.8.0 🚀 Thanks @armano2 for the hard work!