Using braces in an arrow function that returns an object literal actually is ambiguous in JS, which is why you have to wrap it in parentheses, e.g.:
const foo = () => ({foo: 'bar'})
If you omit the parentheses it gets interpreted as a block with a label and a string literal: const baz = () => {baz: 'bar'}
https://astexplorer.net/#/gist/9a86e0b61fda312dce2ea9d10d37f...