// FIR_IDENTICAL
// LANGUAGE: +WarnAboutNonExhaustiveWhenOnAlgebraicTypes
/*
 * KOTLIN DIAGNOSTICS SPEC TEST (NEGATIVE)
 *
 * SPEC VERSION: 0.1-152
 * PRIMARY LINKS: expressions, when-expression -> paragraph 5 -> sentence 1
 * expressions, when-expression, exhaustive-when-expressions -> paragraph 1 -> sentence 1
 * expressions, when-expression, exhaustive-when-expressions -> paragraph 2 -> sentence 9
 * expressions, when-expression, exhaustive-when-expressions -> paragraph 2 -> sentence 10
 * expressions, when-expression -> paragraph 9 -> sentence 2
 * control--and-data-flow-analysis, performing-analysis-on-the-control-flow-graph, variable-initialization-analysis -> paragraph 2 -> sentence 1
 * control--and-data-flow-analysis, performing-analysis-on-the-control-flow-graph, variable-initialization-analysis -> paragraph 2 -> sentence 3
 */

// Base for KT-6227
enum class X { A, B, C, D }

fun foo(arg: X?): String {
    var res = "XXX"
    <!NO_ELSE_IN_WHEN!>when<!> (arg) {
        X.A -> res = "A"
        X.B -> res = "B"
        X.C -> res = "C"
        X.D -> res = "D"
    }
    return res
}