Should => { return be bad text?

[zepumph]

IMO one lined arrow functions that return something should not use the curly braces and return keyword, because it is simpler to just have arg => arg === 3 instead of arg => { return arg === 3; }.

If it is a more complex arrow function, then perhaps it can be on more than one line, and then include those pieces. There are currently 33 usages of => { return.

Marking for developer meeting.

[samreid]

All of the existing 33 cases should be converted, they will be more readable without the {return ;}. I also think the lint rule would be a good idea, thanks!

[jonathanolson]

I could imagine having a filter arrow function where it's one expression to return BUT really needs to take up multiple lines. I find the braces to be helpful for multi-line arrow functions, but I would prefer the one-liners (brace, space, return) to be converted.

[pixelzoom]

Should arg => also be preferred over ( arg ) => ?

[samreid]

Here's some lint rules that may help us:
https://eslint.org/docs/rules/arrow-parens
https://eslint.org/docs/rules/arrow-body-style

[pixelzoom]

@jonathanolson said:

I could imagine having a filter arrow function where it's one expression to return BUT really needs to take up multiple lines. I find the braces to be helpful for multi-line ...

Something like this:

arg => {
  return expression1 && expression2 && expression3 && .... && expressionN;
} 

can be written without curly braces as:

arg => ( expression1 && expression2 && expression3 && .... && expressionN )

[zepumph]

From this issue will investigate two lint rules:

• arrow-parens with the "as-needed" option looked just like what we want, where it will error our for single args that include parens.
• https://eslint.org/docs/rules/arrow-body-style will likely help us with one liner returns.

[zepumph]

There were ~160 issues with arrow-parens "as-needed". The fixes are above, lint rule commit coming in shortly.

I looked into using arrow-body-style "as-needed" but it trying to convert too many arrow functions into complicated one-liners that were 160+ chars long (about 150 of them). So instead I just manually added the namesake of this issue as bad text. There were 30 usages of that.

The rules are now committed and lint is passing. Closing