Port JSCS rules for: requireSpacesInFunction, etc.

[meister]

When does this rule warn? Please describe and show example code:
The rule allows enforcing or preventing spaces after function parens and before curly bracers. Currently it’s possible to control the space between keyword and parenthesis (function ()), but not after keyword+parenthesis. Examples:

function doSomething(){
//                    ^--- Missing/extra space not checked
    return;
}

for (var i = 0; i < items.length; i++){
//                                    ^--- Missing/extra space not checked
}

try {
    doSomething();
} catch (err){
//           ^--- Missing/extra space not checked
    throw new Error('message');
}

switch (local){
//            ^--- Missing/extra space
  case 1:
    doSomething();
}

Is this rule preventing an error or is it stylistic?
Stylistic

Why is this rule a candidate for inclusion instead of creating a custom rule?
Compatibility with JSCS:

{
    "requireSpacesInAnonymousFunctionExpression": {
        "beforeOpeningCurlyBrace": true
    },
    "requireSpacesInFunctionDeclaration": {
        "beforeOpeningCurlyBrace": true
    },
    "requireSpacesInFunction": {
        "beforeOpeningCurlyBrace": true
    }
}

Are you willing to create the rule yourself?

[mysticatea]

Thank you for this issue.

Is space-before-blocks rule not enough?

[meister]

Wow.. I thought I had checked all the rules. I guess I hadn’t – I can indeed use that rule for this specific use case. Closing my issue.

[mysticatea]

FYI: There is a table to identify gap between JSCS and ESLint: #5856 (comment)

[meister]

Thanks so much for feedback and help. Would you also have any idea about the progress of #4680?

It’s the last rule for our company’s requirements. There doesn’t seem to be a good way to port the rules for code like this:

// Required one-var for consecutive declarations
var a = 1,
    b = 2,
    items = [];

// JSCS throws a warning for rule 'requireMultipleVarDecl:true'
// ESLint throws a warning for rule 'one-var'
var c = a;

doSomething(a, b);

// JSCS does not throw a warning, since a statement was in between var declarations
// ESLint throws a warning
var d = c + b;

// Another block with var
// JSCS does not throw a warning for i
// ESLint throws a warning for i
for (var i = 0; i < items.length; i++) {
    // Another block of consecutive vars
    // JSCS does not throw a warning
    // ESLint throws a warning
    var temp1 = a + c,
        temp2 = b + d;

    doSomething(temp1, temp2);
}

[mysticatea]

I'm not sure.
I feel that the responsibility of one-var and vars-on-top is overlapping from your example.

[meister]

Yes, that was exactly my concern. If one-var was more relaxed (like JSCS), but vars-on-top was enforced, the outcome would be almost exactly how it is now (all vars on top, with 1 var declaration). Otherwise, separated blocks of vars (if there are statements in the middle) would be allowed, thus making my example and those of issue #4680 possible.