False positive: unnecessary semicolon

[JakeWharton]

val keyFactory = run {
  val random = Random(1);
  { random.nextInt() }
}

This is a minimal reproducing sample which is contrived, not the actual code.

The problem is that without the semicolon Kotlin thinks that I'm calling the Random constructor with a trailing lambda and fails to compile. Thus, the semicolon is necessary to separate the statement from the lambda (which is an implicit return value).

[romtsn]

Hm, I just tried to run no-semi rule over the sample, but it works just fine.

    @Test
    fun `test`() {
        assertThat(
            NoSemicolonsRule().lint(
                """
                val keyFactory = run {
                  val random = Random(1);
                  { random.nextInt() }
                }
                """.trimIndent()
            )
        ).isEmpty()
    }

Also, looks like it's explicitly handled on line 59:

ktlint/ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/NoSemicolonsRule.kt

Lines 54 to 63 in cb0595b

	private fun doesNotRequirePreSemi(nextLeaf: ASTNode?): Boolean {
	if (nextLeaf is PsiWhiteSpace) {
	val nextNextLeaf = nextLeaf.nextLeaf()
	return (
	nextNextLeaf == null || // \s+ and then eof
	nextLeaf.textContains('\n') && nextNextLeaf.text != "{"
	)
	}
	return nextLeaf == null /* eof */
	}

Am I missing something, or the actual code was a bit different?

[shashachu]

Closing until we get more information.

[Mygod]

More false positive edge cases like this: https://github.com/Mygod/VPNHotspot/blob/e333c859dfe4e675005a56049c510e5fb4ff270c/mobile/src/main/java/be/mygod/librootkotlinx/RootServer.kt#L498

[romtsn]

@Mygod so the semicolon is necessary there, right? Mind filing a new issue?