[eslint-plugin-react-hooks] useReducer purity warning

[hug0b]

Apparently useReducer shouldn't perform side effects like firing async actions or updating state, so I think there should be an eslint warning for that.

[vkurchatkin]

It's not possible to detect side effects with ESLint:

function reducer() {
   // ...
   let foo = bar(); // does bar trigger an effect? No way to tell
  // ...
}

[sophiebits]

As vkurchatkin says, there isn't a good way to lint for this. Thanks for the idea though.