Implicit return and arrow functions about eslint-config

[francescogior]

I like to use implicit return for functions that returns 'templates', even if split in lines

specialTemplate = ({ arg1, arg2, ...args }) => (
  <div>
    <EhiComeVa />
    <BeneTe />
    <UnPoDiAcchiacchi />
    <MiSpiace />
  </div>
)

[gabro]

good point, I think that's acceptable.
It's not a matter of single/multiple lines, rather whether the expression is "linked" to the line where => is.

New formulation of the "rule":

implicit returned expression of arrow functions must begin on the same line of the arrow.

Another similar example

({ foo, bar }) => `
  Hey ${foo}
  ci vediamo al ${bar}?
`

[ascariandrea]

I don't think you resolve readability on last example by make the return explicit:

({ foo, bar }) => {
 return `
  Hey ${foo}
  ci vediamo al ${bar}?
`;
}

What's the fat arrow implicit return purpose? Avoid the overhead of writing return statement for functions with single declaration in body?

I think we should encourage that as long as is readable.

arrayOfArrays.map(x =>
 x.filter(y => someCondition(y))
  .map(y => y * 2)
)

[gabro]

Sorry, I realize I wasn't clear.

The last example I posted is a good one, in my view. The implicit return is made clear by the fact that the expression begins right after the =>.

The last you posted is not, in my opinion. I find it hard to parse, because of the new line after the =>

[gabro]

To sum it up

Good cases

[1, 2, 3].map(i => i);

[1, 2, 3].map(i => {
  return i;
});

[1, 2, 3].map(i => `
  ${i}
`);

[1, 2, 3].map(i => (
  <span>
    ${i}
  </span>
);

Bad cases

[1, 2, 3].map(i =>
  i
);

[1, 2, 3].map(i =>
  (
    <span>
      {i}
    </span>
  )
);

[giogonzo]

implicit returned expression of arrow functions must begin on the same line of the arrow

I'd say this sums it up perfectly, 👍

But I don't think there's any rule for that (slightly related: http://eslint.org/docs/rules/arrow-body-style)

[gabro]

👼 https://github.com/buildo/eslint-plugin-fat-arrow-same-line

[gabro]

Since there's no agreement on this, I'll close it for now