Add "First method line is empty" check

[igorwojda]

OK

fun bar() {
   val a = 2
}

Fail

fun bar() {

   val a = 2
}

[igorwojda]

Probably we should also add an equiwalent check for last empty method line

OK

fun bar() {
   val a = 2
}

Fail

fun bar() {
   val a = 2

}

[sowmyav24]

The last empty method line check should be covered by the rule NoBlankLineBeforeRbraceRule.

[sowmyav24]

Created a PR for first method line empty rule. In addition to the scenarios present above, few others that would be covered are

fun bar() {
   if(someCondition) {

    val a = 2
   }
}

[shashachu]

Fixed in https://github.com/pinterest/ktlint/pull/474

[Zayankovsky]

This method triggers no-empty-first-line-in-method-block error:

fun whatever() {
    window.addMouseListener(object : MouseAdapter() {

        override fun mouseClicked(e: MouseEvent) { /*...*/ }

        override fun mouseEntered(e: MouseEvent) { /*...*/ }
    })
}

Should it be this way? I prefer to keep first line in complex object expressions empty, just like in classes.

[sowmyav24]

https://github.com/pinterest/ktlint/pull/461#issue-286397143

In addition to checking for first line blank in a method block, it will check for any first blank line in code blocks of the method.Please let me know if the subsequent code blocks in the method need to be ignored from this check.

Since, the object expression is inside the method, it triggers a violation for the same.

[Zayankovsky]

Both Kotlin Coding Conventions and Android Kotlin style guide don't mention anything about such a requirement. Why is it forced then? I believe object expressions should be excluded from this check.

[JakeWharton]

Actually the Android Kotlin style guide explicitly mentions this whitespace:

Optionally before the first statement in a function, before the first member of a class, or after the last member of a class (neither encouraged nor discouraged).

[Zayankovsky]

Sorry for not making it clear in the first place, I was talking specifically about object expressions inside methods.

[JakeWharton]

That is an anonymous definition of a class which has the same rules as any other class declaration. If that's not clear, we can amend the guide to explicitly denote that syntactical construct as being synonymous with a class definition.