Require parens in arrow function arguments (arrow-parens)

[doasync]

The "as-needed", { "requireForBlockBody": true } rule is directly inspired by the Airbnb JS Style Guide.

If your function takes a single argument and doesn’t use braces, omit the parentheses. Otherwise, always include parentheses around arguments for clarity and consistency.

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[kaspnilsson]

+1

[philipwalton]

But the Google JS style guide doesn't make the same recommendation as the Airbnb JS style guide. This is what the Google JS style guide says:

Tip: It is a good practice to use parentheses even for single-argument arrows, since the code may still parse reasonably (but incorrectly) if the parentheses are forgotten when an additional argument is added.

For example, this would be valid according to the as-needed rule, but Google style recommends against it:

doSomething(a, b, c, d => e => f);