FIR IDE: fix CCE in getKtExpressionType on loops

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirExpressionTypeProvider.kt

@@ -9,6 +9,7 @@ import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.fir.declarations.FirCallableDeclaration
 import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
+import org.jetbrains.kotlin.fir.expressions.FirLoop
 import org.jetbrains.kotlin.fir.expressions.argumentMapping
 import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.fir.references.FirErrorNamedReference
@@ -40,12 +41,12 @@ internal class KtFirExpressionTypeProvider(
     }
 
     override fun getKtExpressionType(expression: KtExpression): KtType = withValidityAssertion {
-        val coneType = when (val fir = expression.getOrBuildFir(firResolveState)) {
+        when (val fir = expression.getOrBuildFir(firResolveState)) {
-            is FirExpression -> fir.typeRef.coneType
+            is FirExpression -> fir.typeRef.coneType.asKtType()
-            is FirNamedReference -> fir.getReferencedElementType()
+            is FirNamedReference -> fir.getReferencedElementType().asKtType()
+            is FirLoop -> with(analysisSession) { builtinTypes.UNIT }
             else -> error("Unexpected ${fir::class}")
         }
-        coneType.asKtType()
     }
 
     private fun FirNamedReference.getReferencedElementType(): ConeKotlinType {

idea/idea-frontend-fir/testData/components/expressionType/forExpression.kt

@@ -0,0 +1,8 @@
+fun x(): Int {
+    <expr>for(i in 1..2) {}</expr>
+}
+// RESULT
+
+// expression: for(i in 1..2) {}
+// type: kotlin.Unit
+

idea/idea-frontend-fir/testData/components/expressionType/whileExpression.kt

@@ -0,0 +1,8 @@
+fun x(): Int {
+    <expr>while(true) {}</expr>
+}
+// RESULT
+
+// expression: while(true) {}
+// type: kotlin.Unit
+

idea/idea-frontend-fir/tests/org/jetbrains/kotlin/idea/frontend/api/components/HLExpressionTypeTestGenerated.java

@@ -33,4 +33,15 @@ public class HLExpressionTypeTestGenerated extends AbstractHLExpressionTypeTest
     public void testAssignmentExpressionTarget() throws Exception {
         runTest("idea/idea-frontend-fir/testData/components/expressionType/assignmentExpressionTarget.kt");
     }
+
+    @TestMetadata("forExpression.kt")
+    public void testForExpression() throws Exception {
+        runTest("idea/idea-frontend-fir/testData/components/expressionType/forExpression.kt");
+    }
+
+
+    @TestMetadata("whileExpression.kt")
+    public void testWhileExpression() throws Exception {
+        runTest("idea/idea-frontend-fir/testData/components/expressionType/whileExpression.kt");
+    }
 }