UseArrowFunctionsFixer - introduction

[gharlan]

$array = array_map(function (Foo $foo) use ($x) {
    return $foo->bar($x);
}, $array);

is fixed to:

$array = array_map(fn (Foo $foo) => $foo->bar($x), $array);

---

But only real one-liner return statements are transformed. If there is a comment before, or if the return statement uses more lines, there is no point in using an arrow function.
So these cases are not transformed:

foo(function () {
    // explanation for the return statement
    return 1;
});

foo(function () {
    return bar(
       $a,
       $b
    );
});

[julienfalque]

if the return statement uses more lines, there is no point in using an arrow function

Can you elaborate please? I think it would be nice to cover those as well but maybe I'm missing something.

[gharlan]

Maybe it is a matter of taste, but in my opinion the arrow functions without the braces are less readable for multiline return statements.
So for my part, I would like the fixer more, if it does not fix multiline return statements. But if you disagree, I'm open to change the behavior and fix them, too.

But would it be the responsibility of this fixer to change indentation?
When enabling fixing for multiline return statement, at the moment the fixer would fix this input:

foo($x, function () {
    return bar(
       $a,
       $b
    );
}, $y);

to:

foo($x, fn () => bar(
       $a,
       $b
    ), $y);

And this input:

foo($x, function ($a, $b) {
    return $a
        ->aMethodCall()
        ->otherMethodCall($b)
        ->thirdMethod();
}, $y);

to:

foo($x, fn ($a, $b) => $a
        ->aMethodCall()
        ->otherMethodCall($b)
        ->thirdMethod(), $y);

---

I think we should avoid these problems and the fixer should not touch these cases with multiline return statements.

[julienfalque]

I do prefer to fix multiline return statements as well, @SpacePossum @keradus @kubawerlos WDYT? Maybe this can be an option?

But would it be the responsibility of this fixer to change indentation?

No, that would be another fixer.

[gharlan]

do prefer to fix multiline return statements as well, @SpacePossum @keradus @kubawerlos WDYT?

Ping :)

[SpacePossum]

I don't think I would use the multi line version. Therefore I'm fine if this is not part of the first version of the fixer. I think it can be added as an option later.
Thanks for all the work so far!

[julienfalque]

👍 for implementing multiline support later, but without option. It's part of the intended scope of the rule, but it's not fully implemented yet (like we do with rulesets).

[julienfalque]

@gharlan Could you please rebase to fix the conflict?

[keradus]

Thank you @gharlan.