Rule Proposal: nonblock-body-position

From requireNewlineBeforeSingleStatementsInIf.

This rule will enforce the position of bare statements at the body of if, else, do-while',while,for,for-in, orfor-of`.

{
    "nonblock-body-position": ["error",  "below" or "beside" or "any"],
    // or
    "nonblock-body-position": ["error", {
        "position": "below" or "beside" or "any",
        "overrides": {
            "if": null,
            "else": null,
            "do-while": null,
            "while": null,
            "for": null,
            "for-in": null,
            "for-of": null
        }
    }]
}

• position
  • "below" (default) - Requires newline before the body’s statement.
  • "beside" - Disallow newline before the body’s statement.
  • "any" - Does not enforce the position.
• overrides - People can override setting for each kind.

Valid:

/*eslint nonblock-body-position: ["error", "below"]*/

if (a)
    foo();
else
    foo();

while (a)
    foo();

// ignore block statements (those are waned by brace-style)
if (a) { foo(); }
if (a) {
    foo();
}

/*eslint nonblock-body-position: ["error", "beside"]*/

if (a) foo();
else foo();

while (a) foo();

// ignore block statements (those are waned by brace-style)
if (a) { foo(); }
if (a) {
    foo();
}

/*eslint nonblock-body-position: ["error", {"position": "beside", "overrides": {"while": {"position": "below"}}}]*/

if (a) foo();
else foo();

while (a) 
    foo();

Invalid:

/*eslint nonblock-body-position: ["error", "below"]*/

if (a) foo();
else foo();

while (a) foo();

/*eslint nonblock-body-position: ["error", "beside"]*/

if (a)
    foo();
else
    foo();

while (a)
    foo();

/*eslint nonblock-body-position: ["error", {"position": "beside", "overrides": {"while": {"position": "below"}}}]*/

if (a)
    foo();
else
    foo();

while (a) foo();

[kaicataldo]

Sorry to respond to this so late in the game, but I also wonder if we can decide on a name that more clearly describes what this rule is checking. nonblock-body-position wasn’t immediately clear to me, so I can imagine it would be confusing to someone who’s not a project maintainer. I know it’s long, but I think nonblock-statement-body-position would be clearer (hoping we can come up with a shorter/clearer name than that!).

[mysticatea]

nonblock-statement-body-position makes sense to me.

I look at this again, I wonder if nonblock-statement-body-position should include the body of arrow expression as well, or not.

() => foo()
// or
() =>
    foo()