Update 10.2 as per func-style allowArrowFunction

[sambostock]

This updates rule 10.2 following the change in Shopify/eslint-plugin-shopify#188 allowing arrow function expressions.

[sambostock]

The current Why? section looks like this

Why? Function declarations are named, so they’re easier to identify in call stacks. Also, the whole body of a function declaration is hoisted, whereas only the reference of a function expression is hoisted. This rule makes it possible to always use Arrow Functions in place of function expressions.

I'm not sure how to update it, especially since

This rule makes it possible to always use Arrow Functions in place of function expressions.

is already there... 🤔

I could add something like

Arrow functions are acceptable when their this semantics are required, or when function expression typing semantics are desired, if working with TypeScript. For example:

interface Props { className: string }
const Div: React.SFC<Props> = ({className, children}) => <div className={className}>{children}</div>

Thoughts @lemonmade?

[lemonmade]

I think this is all you need. You could bring in the reasoning that sometimes arrow functions are useful for typing, but I’d like to avoid showing the SFC example because that’s actually not the pattern we would usually lean towards (especially in the context of new stuff in React where they are largely demonstrating features in function declarations)

[lemonmade]

I think you can mark this as “also good”