New Rule: requirePaddingNewlinesBeforeKeywords

[avishnyak]

Requires an empty line above the specified keywords unless the keyword is the first expression in a block.

Configured like so:

"requirePaddingNewlinesBeforeKeywords": ["if", "for", "return", "switch", "case", "break", "throw"]

The intent of the rule is to introduce newlines (whitespace) between expressions. Many libraries and individuals already follow this type of convention intuitively.

The rule simply transforms code like this:

String.prototype.hashCode = function () {
    var hash = 0, i, char;
    if (this.length == 0) { return hash };
    for (i = 0, l = this.length; i < l; i++) {
        char = this.charCodeAt(i);
        hash = ((hash << 5) - hash) + char;
        hash |= 0; // Convert to 32bit integer
    }
    return hash;
};

into code like this:

String.prototype.hashCode = function () {
    var hash = 0, i, char;

    if (this.length == 0) {
        return hash
    };

    for (i = 0, l = this.length; i < l; i++) {
        char = this.charCodeAt(i);
        hash = ((hash << 5) - hash) + char;
        hash |= 0; // Convert to 32bit integer
    }

    return hash;
};

Note the empty lines above the if, for and return.

[avishnyak]

One interesting proposal from the conversation on Reddit:

Add a configuration for minimum block size before the rule kicks in. This would prevent the rule from suggesting extra padding lines in very short functions/code blocks.

Example:

Widget.prototype.exec = function(n) {
    var method = n > 0 ? 'get' : 'set';
    return this[method](n);
};

I'm open to thoughts/suggestions on this.

[markelog]

Please correct the indentation

[markelog]

Would you able provide the opposite rule? Could you add more tests? Like one in the doc, it would be preferable to have test for every keywords too.

[avishnyak]

Hi Markelog,

I have provided the opposite rule, fixed indentation and added a bunch of unit tests. Hope that helps.

[mikesherov]

@markelog can you please review this one?

[markelog]

Yep, will do that tomorrow

[markelog]

@avishnyak please rebase with current master, fix the lint errors that will come up after rebase and i'm gonna land this

[avishnyak]

@markelog Should be good to go now.

[coveralls]

Coverage increased (+0.1%) when pulling 8e05b0a on avishnyak:master into 467a170 on jscs-dev:master.

[mikesherov]

@markelog ping!

[markelog]

@avishnyak sorry it took that long, missed the letter with your comment.

One other thing, could these rules accept true value like all rules of JSCS with possible array value?

If value is true it would use this -

node-jscs/lib/utils.js

Line 72 in a16a694

exports.spacedKeywords = [

array?

[coveralls]

Coverage increased (+0.77%) when pulling 3b41606 on avishnyak:master into 467a170 on jscs-dev:master.

[avishnyak]

@markelog This should be good to go now.

[markelog]

Additional spacing?

[markelog]

Could you add a test for true value for each rule?

[markelog]

I finished up with your pull, thank you