Have you checked recently? The docs (https://docs.deno.com/runtime/fundamentals/testing/) specifically mention AVA as being supported. Then again, I'd assume that most devs using Deno just use the built-in `deno test` instead of a third-party testing framework.
> The one area of Node compatibility that I want the most is support for ESLint configs in the Deno linter.
Again, have you checked recently? According to the docs this is supported: "Deno's built-in linter, `deno lint`, supports recommended set of rules from ESLint to provide comprehensive feedback on your code. (...) You can specify custom rules, plugins, and settings to tailor the linting process to your needs." (https://docs.deno.com/runtime/fundamentals/linting_and_forma...)
I've been using Deno for 6 years now. And I'm actually quite happy that most Deno projects don't have a custom testing and linting setup.