[FE 1.0] Check for type mismatch for empty when statements

^KT-47922 Fixed

compiler/testData/diagnostics/tests/sealed/WhenOnEmptySealed.fir.kt

@@ -0,0 +1,11 @@
+// !DIAGNOSTICS: -UNUSED_EXPRESSION
+sealed class Sealed {
+
+}
+
+fun foo(s: Sealed): Int {
+    return <!NO_ELSE_IN_WHEN!>when<!>(s) {
+        // We do not return anything, so else branch must be here
+    }
+}
+

compiler/testData/diagnostics/tests/sealed/WhenOnEmptySealed.kt

@@ -1,12 +1,11 @@
-// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_EXPRESSION
 sealed class Sealed {
 
 }
 
 fun foo(s: Sealed): Int {
-    return <!NO_ELSE_IN_WHEN!>when<!>(s) {
+    return <!TYPE_MISMATCH!><!NO_ELSE_IN_WHEN!>when<!>(s) {
         // We do not return anything, so else branch must be here
-    }
+    }<!>
 }
 

compiler/testData/diagnostics/tests/when/kt47922.fir.kt

@@ -0,0 +1,21 @@
+// ISSUE: KT-47922
+
+package whencase.castissue
+
+sealed class SealedBase {
+    object Complete : SealedBase()
+}
+
+abstract class NonSealedBase {
+    object Complete : NonSealedBase()
+}
+
+sealed class ToState
+
+val sealedTest: SealedBase.() -> ToState? = {
+    <!NON_EXHAUSTIVE_WHEN_STATEMENT!>when<!>(this) {}
+}
+
+val nonSealedTest: NonSealedBase.() -> ToState? = {
+    when(this) {}
+}

compiler/testData/diagnostics/tests/when/kt47922.kt

@@ -0,0 +1,21 @@
+// ISSUE: KT-47922
+
+package whencase.castissue
+
+sealed class SealedBase {
+    object Complete : SealedBase()
+}
+
+abstract class NonSealedBase {
+    object Complete : NonSealedBase()
+}
+
+sealed class ToState
+
+val sealedTest: SealedBase.() -> ToState? = {
+    <!TYPE_MISMATCH!><!NON_EXHAUSTIVE_WHEN_STATEMENT!>when<!>(this) {}<!>
+}
+
+val nonSealedTest: NonSealedBase.() -> ToState? = {
+    <!TYPE_MISMATCH!>when(this) {}<!>
+}

compiler/testData/diagnostics/tests/when/kt47922.txt

@@ -0,0 +1,44 @@
+package
+
+package whencase {
+
+    package whencase.castissue {
+        public val nonSealedTest: whencase.castissue.NonSealedBase.() -> whencase.castissue.ToState?
+        public val sealedTest: whencase.castissue.SealedBase.() -> whencase.castissue.ToState?
+
+        public abstract class NonSealedBase {
+            public constructor NonSealedBase()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+            public object Complete : whencase.castissue.NonSealedBase {
+                private constructor Complete()
+                public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+                public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+                public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+            }
+        }
+
+        public sealed class SealedBase {
+            protected constructor SealedBase()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+            public object Complete : whencase.castissue.SealedBase {
+                private constructor Complete()
+                public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+                public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+                public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+            }
+        }
+
+        public sealed class ToState {
+            protected constructor ToState()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+}