Rule request: Empty and comment lines in function bodies

[driver733]

New Issue Checklist

• Updated SwiftLint to the latest version
• I searched for existing GitHub issues

Rule Request

Description

Each method should fulfill only one goal, therefore, it should not contain any "parts". If you see that the code blocks in your method beg for logical separation - do not separate these blocks using an empty line, instead, refactor your method by splitting it into several ones or create a new class.

In addition, the code, in my opinion, should not have in-line comments. If any kind of explanations is needed, it has to be put in the method or class documentation. Furthermore, if your code requires comments, then it might be necessary to refactor it, so that it would be self-explainatory.

Read: An Empty Line is a Code Smell, Adoption of a custom checkstyle rule

What would trigger?

internal func exceedsLineCountExcludingCommentsAndWhitespace(_ start: Int, _ end: Int, _ limit: Int) -> (Bool, Int) {
        guard end - start > limit else {
            return (false, end - start)
        }
        // I will put this here instead of method documentation. I will also put an empty line below.

        let count = end - start - numberOfCommentAndWhitespaceOnlyLines(startLine: start, endLine: end)
        return (count > limit, count)
    }

What would not trigger?

internal func exceedsLineCountExcludingCommentsAndWhitespace(_ start: Int, _ end: Int, _ limit: Int) -> (Bool, Int) {
        guard end - start > limit else {
            return (false, end - start)
        }
        let count = end - start - numberOfCommentAndWhitespaceOnlyLines(startLine: start, endLine: end)
        return (count > limit, count)
    }

Configurable?

The rule should not be configurable.

Opt-in or enabled?

This rule could be a personal preference or coding style from various individuals, so it could be kept as opt-in.